Touch-based biomarker monitoring system

Abstract

Provided herein are methods, devices, and systems relating to solid state sensors and sensor readings for touch-based rapid physiological and chemical sensing.

Description

Cross-references

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 512,248, filed July 6, 2023, which is incorporated herein by reference. background

[0002] Sweat contains numerous small-molecule biomarkers and can be a promising alternative biofluid for non-invasive sensing of blood and interstitial fluid. However, sweat-based sensing can be limited in accuracy and practicality because these methods typically require additional steps in the sweat generation and collection process, have longer latency compared to blood-based sensing, and can be affected by individual variability and sweating rates. Therefore, there is a need for accurate, convenient, rapid, and non-invasive biomarker sensing that utilizes sweat as an readily available sample to measure a wide range of biomarkers. Overview

[0003] In one aspect, this disclosure provides a system comprising: a test strip including a solid-state electrochemical sensor layer and a conductive layer; and a test strip reading device including a slot configured to receive a first portion of the test strip and retain a second portion of the test strip uncovered, wherein the uncovered surface is an accessible portion for contact with a user's skin.

[0004] In some embodiments, the system further includes a computer processor operatively coupled to the test strip reading device, the computer processor being configured to use the test strip reading device to determine the properties of the skin. In some embodiments, the test strip reading device includes a physical data port. In some embodiments, the physical data port is a Universal Serial Bus (USB) port. In some embodiments, the USB port is configured to allow communication between the test strip reading device and a computing system. In some embodiments, the USB port is configured to receive power from the computing system when connected to the computing system. In some embodiments, the test strip reading device includes a wireless communication module. In some embodiments, the wireless communication module includes a Bluetooth® communication module, a Wi-Fi® communication module, a Near Field Communication (NFC) module, a cellular communication module, a radio communication module, an ultra-wideband communication module, or any combination thereof. In some embodiments, the test strip reading device is reusable. In some embodiments, the test strip is reusable. In some embodiments, the test strip can be reused for at least about 3 days. In some embodiments, the test strip can be reused for at least about 7 days. In some embodiments, the test strip can be reused at least about 15 times. In some embodiments, the test strip is not reusable. In some embodiments, the test strip reading device is not reusable. In some embodiments, the test strip reading device is configured to allow the removal of the test strip after testing the skin. In some embodiments, after the removal of the test strip, the test strip reading device is configured to receive an additional test strip. In some embodiments, the test strip reading device is configured to attach to a computing device. In some embodiments, the computing device is a mobile phone, watch, wearable device, or laptop computer. In some embodiments, the test strip reading device includes a microprocessor configured to interface with the test strip to acquire measurements from the test strip. In some embodiments, the system also includes a cover positioned to protect an uncovered surface of the test strip. In some embodiments, the cover is slidable relative to the test strip reading device. In some embodiments, the cover is attached to the test strip reading device using a hinge. In some embodiments, the cover includes one or more sensors configured to determine an open or closed state of the cover. In some embodiments, the test strip reading device has a volume of up to about 4 cubic centimeters (cm²). 3The volume of the test strip. In some embodiments, the test strip reading device is configured to guide the user's finger to the test strip. In some embodiments, the system further includes a display in the test strip reading device. In some embodiments, the system further includes one or more physical buttons. In some embodiments, the test strip reading device includes one or more sensors. In some embodiments, the one or more sensors are configured to acquire one or more signals, including the user's temperature, the temperature of the test strip reading device, the user's moisture level, humidity, the user's sweat gland density, the user's sweating rate, the user's transdermal water loss rate, pressure, the user's skin hydration level, the user's heart rate, the user's blood oxygen level, the user's blood pressure, the user's skin conductance, the user's skin capacitance, the user's skin resistance, the user's skin impedance, or any combination thereof. In some embodiments, the test strip reading device has a credit card shape factor, a keychain shape factor, or a ring shape factor. In some embodiments, the test strip reading device is integrated into a laptop computer. In some embodiments, the test strip reading device is configured to be integrated into or associated with a mobile phone housing. In some embodiments, the test strip reading device is configured to be covered by a portion of the mobile phone housing.

[0005] In another aspect, this disclosure provides a method comprising: (a) providing a test strip reading device for holding a test strip, the test strip including a solid-state electrochemical sensor layer and a conductive layer; (b) bringing the test strip into contact with a portion of a subject's skin; (c) using the solid-state electrochemical sensor layer and the conductive layer to generate an electrical measurement based on biomarkers from said portion of the subject's skin or sweat thereon; and (d) using said electrical measurement to determine the nature of said biomarkers of the subject.

[0006] In some embodiments, the nature of the biomarker is the subject's blood glucose level. In some embodiments, the method further includes using a calibrated measurement when determining the nature of the biomarker. In some embodiments, the nature of the biomarker is determined without pre-calibration. In some embodiments, the method further includes, prior to (b), opening a cover attached to the test strip reading device to expose the test strip. In some embodiments, the test strip is reusable. In some embodiments, the test strip can be reused at least about 15 times.

[0007] This article provides methods, devices, and systems designed for rapid touch-based physiological and chemical sensing.

[0008] In some embodiments, the system includes a portable sweat-based analyte monitoring system. In some embodiments, the sensor device includes a test strip comprising a solid-state electrochemical sensing layer and a conductive layer; and a test strip reading device configured to contact a portion of a user's skin to receive a sample from the skin, wherein the test strip reading device is configured to receive the test strip. In some embodiments, the sample includes sweat.

[0009] In some embodiments, the conductive layer comprises a conductive material. In some embodiments, the conductive material comprises one or more of a metal, a doped ceramic, a carbonaceous material, or a conductive polymer. In some embodiments, the metal comprises one or more of gold, silver, copper, ruthenium, rhodium, platinum, bismuth, tungsten, iron, titanium, rhenium, osmium, or iridium. In some embodiments, the doped ceramic comprises one or more of indium tin oxide, aluminum-doped zinc oxide, or fluorine-doped tin oxide. In some embodiments, the carbonaceous material comprises one or more of graphite, carbon black, carbon nanotubes, graphene, or reduced graphene oxide. In some embodiments, the conductive polymer comprises one or more of poly(3,4-ethylenedioxythiophene)polystyrene sulfonate, polypyrrole, polyaniline, polythiophene, or poly(p-phenylene) or polyphenylene diamine.

[0010] In some embodiments, the conductive layer is configured to conduct electrochemical signals and establish an electrical connection to the test strip reader when the test strip is inserted into the test strip reader. In some embodiments, the sensor includes an electrochemical transducer that incorporates biometric functionality. In some embodiments, the sensor comprises one or more of an enzyme, an ion carrier, a binding peptide, a polynucleotide, an aptamer, a molecularly imprinted polymer, or a microorganism. In some embodiments, the enzyme comprises one or more of glucose oxidase, glucose dehydrogenase, alcohol oxidase, alcohol dehydrogenase, lactate oxidase, lactate dehydrogenase, cholesterol oxidase, uricase, urease, ascorbic acid oxidase, horseradish peroxidase, catalase, tyrosinase, creatinine deiminase, amylase, glutamate oxidase, xanthine oxidase, bilirubin oxidase, hydroxybutyrate dehydrogenase, hydroxybutyrate oxidase, D-amino acid oxidase, L-amino acid oxidase, pyruvate oxidase, or acetoacetate dehydrogenase. In some embodiments, the binding peptide comprises an antibody or an antigen-binding fragment.

[0011] In some embodiments, the sensor further comprises one or more of a cofactor, mediator, stabilizer, surfactant, polymer, plasticizer, crosslinking agent, crosslinking terminator, or crosslinking initiator. In some embodiments, the cofactor comprises one or more of nicotinamide adenine dinucleotide, nicotinamide adenine dinucleotide phosphate, flavin adenine dinucleotide, flavin mononucleotide, thiamine pyrophosphate, biotin, heme, coenzyme A, coenzyme Q, cobalamin, pyridoxal phosphate, tetrahydrofolate, or S-adenosylmethionine. In some embodiments, the mediator comprises one or more of ferrocene and ferrocene derivatives, ferricyanide, ferrocyanide, Prussian blue, quinones, tetrathiofulvalene, organic dyes (methylene blue, Meldora blue), osmium complexes, or ruthenium complexes. In some embodiments, the stabilizer comprises one or more of glycerol, trehalose, chitosan, albumin, polyethylene glycol, calcium chloride, silica, polyol, diethyldithiocarbamate, or mercaptoundecyl alcohol. In some embodiments, the surfactant comprises a Pluronic triblock copolymer. In some embodiments, the polymer comprises one or more of alginate, chitosan, acrylate, methacrylate, or sugar. In some embodiments, the polymer comprises polymer monomers. In some embodiments, the plasticizer comprises one or more of di-2-ethylhexyl phthalate, diisononyl phthalate, dioctyl adipate, diisononyl adipate, triphenyl phosphate, polyethylene glycol, dibutyl sebacate, dioctyl sebacate, tributyl acetylacetonate, or epoxidized soybean oil. In some embodiments, the crosslinking agent comprises one or more of glutaraldehyde, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide, polyethylene glycol diglycidyl ether, glyoxal, benzophenone, disuccinimide succinate, bis(sulfosuccinimide) succinate, or dithiobis(succinimide propionate). In some embodiments, the crosslinking initiator comprises one or more of azobisisobutyronitrile, potassium persulfate, ammonium persulfate, tetramethylethylenediamine, benzoyl peroxide, or Irgacure 2959.

[0012] In some embodiments, the test strip further includes a substrate. In some embodiments, the substrate comprises one or more of plastic, ceramic, or natural materials. In some embodiments, the substrate comprises one or more of polyethylene, polypropylene, polyethylene terephthalate, polyester, polyimide, polydimethylsiloxane, alumina, silicon, or paper. In some embodiments, the substrate is subjected to mechanical, chemical, and / or physical treatments to modify its properties. In some embodiments, the characteristics include one or more of surface roughness, hydrophobicity, dielectric constant, or electrostatic charge. In some embodiments, the substrate treatment includes one or more of alkaline chemical etching, plasma etching, electroplating, abrasion, laser ablation, sputtering, heating, and physical or chemical vapor deposition. In some embodiments, the substrate treatment improves sample adhesion and / or sample compatibility.

[0013] In some embodiments, the test strip further includes an insulating layer. In some embodiments, the insulating layer comprises a non-conductive material. In some embodiments, the insulating layer is waterproof. In some embodiments, the insulating layer is rigid. In some embodiments, the insulating layer is transparent. In some embodiments, the insulating layer has antibacterial properties. In some embodiments, the insulating layer covers a portion of the test strip to define an exposed area for contact with skin. In some embodiments, the insulating layer is deposited or attached to another layer of the test strip.

[0014] In some embodiments, the test strip further includes an anti-interference layer. In some embodiments, the anti-interference layer comprises one or more of a metal, a mediator, a negatively charged or positively charged molecule. In some embodiments, the mediator comprises one or more of ferrocene and ferrocene derivatives, ferrocyanide, ferrocyanide, Prussian blue, quinones, tetrathionene, organic dyes, osmium complexes, or ruthenium complexes. In some embodiments, the organic dye comprises one or more of methylene blue or Meldora blue. In some embodiments, the negatively charged or positively charged molecule comprises one or more of Nafion, polychlorotrifluoroethylene, polyfluoroalkane, fluororubber, chitosan, polyethyleneimine, polyurethane, poly(p-phenylene diamine), polystyrene sulfonate, polyvinyl sulfate, polyvinyl alcohol, or polyvinyl chloride. In some embodiments, the fluororubber comprises one or more copolymers of vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, and perfluoromethyl vinyl ether. In some embodiments, the fluororubber includes the addition of ethylene and propylene to the copolymer.

[0015] In some embodiments, the test strip further includes a protective layer. In some embodiments, the protective layer comprises a polymer. In some embodiments, the polymer comprises one or more of Nafion, polychlorotrifluoroethylene, chitosan, methyl- or ethyl-cellulose, polyvinyl chloride, polyurethane, poly(p-phenylenediamine), silicone, polytetrafluoroethylene, polyolefin, polyester, polycarbonate, copolymer, polyvinylidene fluoride, polymethyl methacrylate, polyvinyl alcohol, polyethylene glycol, polyacrylamide, polyacetate, polyvinylpyrrolidone, polyethylene oxide, or polysulfides. In some embodiments, the protective layer is permeable. In some embodiments, the protective layer is configured to protect the underlying layer from mechanical and / or chemical damage.

[0016] In some embodiments, the test strip further includes a conditioning layer. In some embodiments, the conditioning layer comprises a polymer and a surfactant. In some embodiments, the conditioning layer is configured to adjust the hydrophilicity and electrostatic charge of the electrode. In some embodiments, the test strip is for single use. In some embodiments, the test strip can be reused at least 10 times.

[0017] In some embodiments, the layer is patterned to improve sweat contact and signal transduction. In some embodiments, the pattern includes one or more of interdigitated patterns, concentric patterns, and radial interdigitated patterns. Each segment of the lines or arcs of the pattern is spaced approximately 1 mm apart. In some embodiments, the analyte comprises one or more of sodium, potassium, calcium, magnesium, chloride, fluoride, glucose, lactate, alcohol (ethanol), ketone (β-hydroxybutyrate, acetoacetate), cortisol, uric acid, urea, ascorbate, creatinine, creatine, amino acids (e.g., glycine, leucine, proline, lysine, alanine, glutamine, tyrosine, tryptophan, cysteine, etc.), levodopa, caffeine, cannabinoids, cocaine, opioids, explosives, or nerve agents.

[0018] In some embodiments, the device includes a housing and a circuit board. In some embodiments, the circuit board includes a microcontroller, a signal generation and processing chip, a data storage chip, and a connector configured to receive a test strip. In some embodiments, the circuit board also includes one or more of a wireless transmission function, an antenna, a display panel, indicator lights, user input buttons, or a power supply. In some embodiments, the user input buttons include electrical buttons or mechanical buttons, or a combination thereof. In some embodiments, the circuit board is configured to generate electrochemical measurements when a test strip is inserted into the device and a sample is brought into contact with the test strip. In some embodiments, the electrochemical measurements include one or more of open-circuit voltage measurement, chronopotentiometrics, chronoamperometry, chronocoulometrics, cyclic voltammetry, differential pulse voltammetry, square wave voltammetry, linear sweep voltammetry, AC impedance spectroscopy, or DC internal resistance measurement. In some embodiments, the circuit board is configured to generate an electrical signal based on the electrochemical measurements from the sample and to process the electrical signal to determine the concentration of an analyte. In some embodiments, the circuit board processes the electrical signal into an analyte concentration using a pre-programmed algorithm and user-input calibration data. In some embodiments, the pre-programmed algorithm includes two-point or single-point linear regression using user-input calibration data. In some embodiments, calibration data input by the user is obtained from another analyte monitoring device. In some embodiments, the other analyte monitoring device includes a blood glucose monitor or a continuous glucose monitor. In some embodiments, the pre-programmed algorithm is personalized for the user. In some embodiments, the pre-programmed algorithm is individualized for different fingers of the user. In some embodiments, the data storage chip is configured to store one or more of the following: the number of times the test strip was used, the raw signal, the processed data, the measurement time, or personalized and individualized calibration data. In embodiments, the analyte is referred to herein as a small molecule biomarker.

[0019] In some embodiments, the circuit board is configured to deliver stored information to an auxiliary device. In some embodiments, the auxiliary device includes one or more computers, mobile devices, or cloud-based data centers. In some embodiments, the auxiliary device performs data analysis and data visualization on the stored information. In some embodiments, the device also includes one or more optical or electrical sensors. In some embodiments, the optical or electrical sensors are configured to measure one or more physiological and physical signals from the skin. In some embodiments, the other one or more physiological and physical signals include one or more of temperature, moisture level, sweat gland density, sweating rate, transdermal water loss rate, pressure, hydration level, heart rate, skin conductance, skin capacitance, skin resistance, skin impedance, or blood oxygen level. In some embodiments, a pre-programmed algorithm uses the other one or more physiological and physical signals to correct for calculating analyte concentrations based on electrical signals. In some embodiments, the device also includes an optical, capacitive, or ultrasonic fingerprint scanner to identify the user and finger touching the test strip.

[0020] In some embodiments, the housing is configured to protect the circuit board and test strip when inserted into the device. In some embodiments, the housing includes a movable cover to cover a portion of the test strip inserted into the device when the movable cover is closed, and to expose a portion of the test strip when the movable cover is open. In some embodiments, the cover includes a replaceable wipe or scraper to remove sample residue after contact with skin. In some embodiments, the housing includes a replaceable wiper for wiping the skin before contact with the test strip. In some embodiments, the housing includes a mechanical guide for contact with skin.

[0021] This document provides a non-invasive method for detecting analytes from fingertips, the method comprising: inserting a test strip of any of the preceding claims into a device of any of the preceding claims; placing a portion of a user's skin in contact with the test strip; and obtaining a reading of the analyte from the test strip reading device. In other embodiments, this document provides a non-invasive method for monitoring analytes from fingertips, the method comprising: receiving a sample from a user's skin on a test strip of any of the preceding claims inserted into a device of any of the preceding claims via skin contact with the test strip; generating an electrical signal based on an electrochemical measurement of the analyte using the solid-state electrochemical sensor; measuring the concentration of the analyte in the sample based on the electrical signal; calculating the systemic concentration of the analyte in the user by the device based on the concentration of the analyte in the sample; and providing the systemic concentration of the analyte on a display of the device.

[0022] This document provides a method for repairing test strips for sweat-based analyte monitoring systems, the method comprising: depositing one or more layers on top of a substrate; and attaching the deposited layer to the substrate or a prior layer, wherein the test strip includes the substrate, a conductive layer, a solid-state electrochemical sensor, and an insulating layer. In some embodiments, deposition includes one or more of electrodeposition, sputtering, physical and chemical vapor deposition, screen printing, transfer printing, dip coating, spraying, spin coating, doctor blade coating, inkjet printing, drop casting, or micro-dot patterning. In some embodiments, the method of attaching the layer includes one or more of cold pressing, hot pressing, bonding, curling, or embedding. In some embodiments, the layer is patterned to improve sweat contact and signal transduction. Patterning includes one or more of the following: direct deposition or printing, mask deposition or printing, mask etching, laser ablation, laser cutting, mechanical abrasion, or mechanical cutting. By incorporating via reference

[0023] All publications, patents and patent applications mentioned in this specification are incorporated herein by reference to the extent that each individual publication, patent or patent application is specifically and individually indicated to be incorporated by reference. Attached Figure Description

[0024] The novel features of this disclosure are set forth in particular in the appended claims. A better understanding of the features and advantages of this disclosure will be obtained by referring to the following detailed description of the invention, along with the accompanying drawings, which illustrate illustrative embodiments in which the principles of this disclosure are utilized: Figure 1 An exploded perspective view of an exemplary embodiment of an electrochemical solid-state sensor is shown.

[0025] Figure 2 A illustrates a chemical or physical treatment process on the substrate, accompanied by a certain temperature. Figure 2 B shows the laser ablation of a metal sputtered substrate.

[0026] Figure 3 shows a signal comparison with and without an anti-interference layer for common interfering substances (acetaminophen (AP), uric acid (UA), and ascorbic acid (AA)).

[0027] Figure 4 shows a comparison of glucose sensitivity with and without substrate treatment, as well as stability tests for multiple repeated experiments.

[0028] Figure 5 A schematic diagram of the sensor is shown, in which a finger is applied to the sensor to collect sweat and biomarkers.

[0029] Figure 6 A schematic diagram of a system combining a biosensor and a housing device is shown.

[0030] Figure 7 A schematic diagram is shown for inserting test strips into the device. Figure 8 A schematic diagram of a system combining an electrochemical sensing test strip, a device, and a battery is shown.

[0031] Figure 9 A schematic diagram is shown of the cover for opening / closing the notch retainer for the test strip.

[0032] Figures 10A-10B An example of a credit card shape factor test bar reading device is shown.

[0033] Figures 11A-11C An example of a keychain shape factor test bar reading device is shown.

[0034] Figures 12A-12B An example of a laptop-type shape factor test bar reading device is shown.

[0035] Figures 13A-13C An example of a mobile phone casing shape factor test bar reading device is shown.

[0036] Figures 14A-14C An example of a ring shape factor test bar reading device is shown.

[0037] Figures 15A-15C An example of a Universal Serial Bus plug-in shape factor test bar reading device is shown.

[0038] Figures 16A-16C An example of a smart watch strap shape factor test bar reading device is shown.

[0039] Figures 17A-17B An example of a handheld shape factor test bar reading device is shown.

[0040] Figures 18A-18B An example of a pressure switch and its integration into a test bar reading device is shown.

[0041] Figures 19A-19C An example of a pressure switch in an activation neutralization test strip reading device is shown.

[0042] Figure 20 An example of an exploded view of a test bar reading device is shown. Detailed description

[0043] Sweat contains a variety of small-molecule biomarkers and may be a promising alternative biofluid for non-invasive sensing of blood and interstitial fluid. Sweat biomarker sensing can be achieved using a combination of biosensors with high specificity for the target analyte, sweat generation and collection mechanisms, and electronic devices for signal generation, data processing, and human interfaces.

[0044] Previous sweat biomarker monitoring systems may have relied on motion-based sweat, transdermal drug delivery-induced sweat, or heat-induced sweat collected using microfluidic mechanisms or hydrogels for subsequent interaction with signal transduction sensor electrodes. Such methods can be limited in accuracy and practicality because they typically require lengthy and arduous sweat generation and collection processes, have significant delays compared to blood-based biomarker monitoring, and are heavily influenced by individual variability and sweating rates.

[0045] Recent fingertip-based sensors allow for the collection of sweat from fingertips without exercise or active extraction, using hygroscopic porous hydrogels for analyte collection and electrolytes covering the electrode surface for rapid, non-invasive sensing. However, such sensors may still require the use of easily drying hydrogels and introduce additional problems during sensing due to analyte dilution and accumulation. The use of hydrogels is difficult in terms of their implementation and storage, making the devices and operation less practical and accessible to users.

[0046] In one aspect, this disclosure provides a novel portable integrated sweat monitoring system comprising two main components: a solid electrochemical test strip and an electronic device into which the test strip can be inserted. The system can be used, for example, for non-invasive sweat sensing, wherein a user inserts the test strip into the electronic device and places their finger on the test strip for a given amount of time, during which time the electronic device performs an electrochemical measurement on the test strip to generate a raw electrical signal; the electrical signal is then processed by the electronic device to produce a desired result, such as the concentration of a target analyte.

[0047] This document discloses methods, apparatus, and systems relating to solid-state gel-free sensors for rapid touch-based physiological and chemical sensing. The disclosed techniques can be implemented in some embodiments to provide novel, non-invasive, painless sensors for direct sampling and frequent measurement of biomarkers and related physiological states in sweat, such as sweating rate.

[0048] The novel portable sweat monitoring system presented in this paper offers various advantages, including but not limited to more accurate, convenient, rapid, and non-invasive biomarker sensing. This system eliminates the need for sweat stimulation, instead utilizing natural fingertip sweat as the biofluid for sensing, which can be highly advantageous. It can comprise two main components: a disposable electrochemical sensing test strip and a reusable electronic instrument. The unique design and composition of the test strip allow for the detection and quantification of biomarkers in very small amounts of natural fingertip sweat (<100 nL), unaffected by sweat rate, chemical and physical interferences, and environmental factors. The electronic instrument can feature specialized signal generation and conversion algorithms, as well as unique mechanical design considerations to increase user-friendliness and limit human error during its use. Electrochemical sensing of biomarkers

[0049] A. Sweat-based monitoring system In some embodiments, the system may include a portable sweat-based analyte monitoring system. In some embodiments, the sensor device includes a test strip comprising a solid-state electrochemical sensor layer and a conductive layer; and a test strip reading device configured to contact a portion of a user's skin to receive a sample from the skin, wherein the test strip reading device is configured to receive the test strip. The sample includes sweat.

[0050] In some embodiments, the sensor can operate with direct contact between the user and a fingertip or any other skin surface that emits passive, natural, thermoregulating sweat, and measures the concentration of various ions and biomolecules (e.g., sodium, potassium, chloride, glucose, lactic acid, urea, uric acid, bilirubin, hydroxybutyric acid, vitamins, amino acids, alcohols, levodopa, caffeine, cortisol, insulin, explosives, anesthetics, nerve agents, fluorides, calcium, zinc, lead, cadmium, mercury) in the sweat via electrical (e.g., conductivity, piezoresistive, thermal resistance, piezoresistive, thermoelectric, piezoelectric), chemical (e.g., nonspecific adsorption, specific binding, intercalation, insertion), or electrochemical (e.g., catalytic, redox) transduction methods.

[0051] For diabetic patients requiring continuous blood glucose monitoring, finger-prick glucometers can be used, which can be highly invasive and painful. Alternative continuous glucose monitoring systems still require inserting a needle into the body for continuous sensing, which is invasive and requires maintenance. To sense glucose and many other biomarkers important for human health, new wearable sensors can be used, characterized by non-invasive sensing of more accessible biofluids such as sweat or interstitial fluid. The use of such epidermal sensors may require arduous analyte extraction processes, such as exercise, heating, or iontophoresis, and relies on complex device architectures such as microfluidic devices, microneedles, iontophoresis patches, etc. This process can be invasive, complex, and highly maintainable for self-monitoring. Furthermore, these devices may require large quantities of analytes or special analyte uptake mechanisms, such as microfluidic channels or hydrogels, to ensure coverage of the electrode surface.

[0052] Finger-touch technology enables the collection of sweat from fingertips without movement or active extraction. It utilizes a hygroscopic porous hydrogel for analyte collection and an electrolyte covering the electrode surface for rapid, non-invasive sensing, and can be used to sense a variety of chemicals. However, the process may still require the use of an easily drying hydrogel, and additional problems may arise during sensing due to analyte dilution and accumulation. The use of hydrogels can be challenging in its implementation and storage, making the device and operation less practical and accessible to users. Figure 5 Examples of test bars with sensors implemented based on some embodiments of the disclosed technology are shown. Figure 5 The illustration shows a fingertip contacting a sensor on a test strip, implemented as in some embodiments of the disclosed technology, and examples of gel-free sensors for rapid touch-based physiological and chemical sensing implemented in some embodiments of the disclosed technology. Embodiments of the disclosed technology eliminate the need for external analyte collection mechanisms such as those using hydrogels, hydrocolloids, porous materials, microfluidic channels, microneedles, iontophoresis, reverse iontophoresis, transdermal cholinergic agent delivery, etc., and allow for rapid, maintenance-free, user-friendly near real-time biochemical and physiological sensing.

[0053] In embodiments, the techniques described herein can be implemented using closely spaced electrodes functionalized with transducers for biomarkers, allowing users to perform sensing in a rapid, non-invasive, painless, and maintenance-free manner. The closely spaced or interdigitated electrode design avoids the use of hydrogels, making the device more accessible, simple, stable, and suitable for frequent, repetitive measurements. The disclosed techniques can be implemented in some embodiments to provide a method for sensing epidermal sweat that eliminates the need for any arduous sweat collection processes, such as exercise, heating, chemical stimulation, or iontophoresis extraction.

[0054] A single sensor strip can be reliably used for repeated glucose tests, allowing users to track their glucose levels and conveniently and closely detect potential blood glucose abnormalities. The initial day, a simple 2-data-point personalized calibration (at different blood glucose levels) can fully address individual differences (e.g., sweating rate). The sensor provides highly accurate blood glucose concentration data, closely matching capillary blood glucose (CBG) levels obtained from commercially available finger-prick tests.

[0055] Therefore, this design enables fingertip sensing based on solid-state contact, offering significant advantages over hydrogel-based sweat collection mechanisms in terms of simplicity, reusability, testing frequency, and data reproducibility. For comparison, the same finger can be repeatedly tested on the same sensor, with and without hydrogel, and under conditions of stable and decreasing glucose levels (30 minutes before and after meals, respectively). Under constant glucose levels, the hydrogel-covered sensor may exhibit an increased current signal due to the residue and accumulation of glucose from repeated touches, while the solid-state sensor shows good stability, with the differences through these repeated contacts being negligible. Conversely, under decreasing glucose levels, the solid-state sensor accurately captures the dynamically decreasing glucose concentration, while the hydrogel-covered sensor exhibits a slowly increasing response due to the combined competitive effect of the decreasing glucose concentration and its accumulation in the gel, leading to an unrealistically increased response associated with this residue effect. The reproducibility of the sensor at different glucose concentrations can be investigated by five repeated tests under fasting conditions.

[0056] The disclosed techniques can be implemented in some embodiments to provide a highly accurate, simple, and rapid glucose sensing protocol using interdigitated, solid-state PEDOT:PSS-based electrodes that leverage passive perspiration from the fingertips for reliable, near-real-time, non-invasive monitoring of glucose levels. Eliminating the need for a sweat-collecting hydrogel interface greatly simplifies operation, allowing for frequent, repeated measurements throughout the day, while providing superior analytical performance compared to conventional hydrogel-based SPE sensors. The sensor is compatible with diverse subjects and allows for rapid, personalized calibration (based on only the initial two finger-prick measurements), showing great promise as an alternative to painful, frequent finger-prick SMBG and invasive CGM techniques for continuous 24-hour blood glucose monitoring. The new protocol offers high accuracy with low MARD and a good CEGA (Clarke Error Grid Analysis) index, comparable to commercial glucose sensing technologies, as well as painless (bloodless and needle-free) and rapid operation.

[0057] The same low-cost sensor can be used without any restabilization. This convenient touch-based sensing can significantly increase the frequency of self-testing compared to traditional SMBG, providing enhanced diabetes control. The disclosed techniques can also be implemented in some embodiments to enable large-scale validation using diverse subjects and further improve speed and simplicity, develop advanced bloodless calibration processes and predictive algorithms, and improve the understanding of the role of passive fingertip sweating and electrode geometry in hydrogel-free (interdigital) settings. Translating this touch-based sensing into passive, repetitive monitoring of glucose throughout the day could further facilitate its practical use as a true CGM alternative.

[0058] Combined with engineering efforts to create user-friendly sensor prototypes, these developments could lead to highly reliable, painless, rapid, and frequent glucose self-testing for home and other decentralized settings to improve diabetes management, as well as simplified and accurate non-invasive monitoring for other key sweat biomarkers, such as ketones, cortisol, drug-like compounds, etc.

[0059] Test bar component The test strip may include at least one substrate. In some cases, the substrate comprises one or more types of plastic, ceramic, or natural materials, such as polyethylene, polypropylene, polyethylene terephthalate, polyester, polyimide, polydimethylsiloxane, alumina, silicon, and paper. In some cases, the sensor comprises a substrate made of glass, silicon, paper, textiles, or polymeric plastics or elastomers. Furthermore, such test strips can be fabricated or integrated onto other platforms; for example, the substrate may include a silicone or polyurethane film, such as a polyurethane-based elastomer.

[0060] In some cases, the surface of the substrate can be mechanically, chemically, or physically treated to alter its surface roughness, cleanliness, hydrophobicity, dielectric constant, and electrostatic charge, thereby improving adhesion and compatibility with sweat sensing. In some cases, processing techniques include, but are not limited to: acid or alkali chemical etching, plasma etching, electroplating, abrasion, laser ablation, sputtering, heating, and physical or chemical vapor deposition.

[0061] In some embodiments, the test strip includes an electrochemical sensor layer. The electrochemical sensor layer may include at least an electrochemical transducer with biometric functionality, such as an enzyme (glucose oxidase, glucose dehydrogenase, alcohol oxidase, alcohol dehydrogenase, lactate oxidase, lactate dehydrogenase, cholesterol oxidase, uricase, ascorbic acid oxidase, horseradish peroxidase, catalase, tyrosinase, creatine deiminase, amylase, glutamate oxidase, xanthine oxidase, bilirubin oxidase, hydroxybutyrate dehydrogenase, hydroxybutyrate oxidase, acetoacetate dehydrogenase), an ion carrier, an antibody, a nucleic acid, an aptamer, a molecularly imprinted polymer, or a microorganism.

[0062] The electrochemical sensing layer may include one or more cofactors, such as nicotinamide adenine dinucleotide, nicotinamide adenine dinucleotide phosphate, flavin adenine dinucleotide, flavin mononucleotide, thiamine pyrophosphate, biotin, heme, coenzyme A, coenzyme Q, cobalamin, pyridoxal phosphate, tetrahydrofolate, and S-adenosylmethionine.

[0063] The electrochemical sensing layer may include one or more mediators, such as ferrocene and ferrocene derivatives, ferricyanide, ferrocyanide, Prussian blue, quinones, tetrathionyl fulvalene, organic dyes (methylene blue, Meldora blue), osmium or ruthenium complexes.

[0064] The electrochemical sensing layer may include one or more stabilizers, such as glycerol, trehalose, chitosan, albumin, polyethylene glycol, calcium chloride, silica, polyols, diethyl dithiocarbamate, mercaptoundecyl alcohol, or surfactants, such as Pluronic triblock copolymers. Examples of surfactants include, but are not limited to, fluorinated surfactants (e.g., surfactants containing fluorinated groups), surfynol (e.g., tetramethyldecynyl glycol), triton-X 100, triton-X 114, etc.

[0065] The electrochemical sensing layer may include one or more polymers or polymer monomers (alginate, chitosan, acrylate, methacrylate, sugars), plasticizers (di-2-ethylhexyl phthalate, diisononyl phthalate, dioctyl adipate, diisononyl adipate, triphenyl phosphate, polyethylene glycol, dibutyl sebacate, dioctyl sebacate, acetyl tributyl citrate, epoxidized soybean oil).

[0066] The electrochemical sensing layer may include one or more crosslinking agents, such as glutaraldehyde, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide, polyethylene glycol diglycidyl ether, glyoxal, benzophenone, disuccinimide succinate, bis(sulfosuccinimide) succinate, and dithiobis(succinimide propionate).

[0067] The electrochemical sensing layer may include one or more crosslinking initiators, such as azobisisobutyronitrile, potassium persulfate, ammonium persulfate, tetramethylethylenediamine, benzoyl peroxide, and Irgacure 2959. The electrochemical sensing layer may include one or more crosslinking terminators (e.g., lysine, glycine, polylysine, etc.).

[0068] In some embodiments, the test strip includes at least a conductive layer. In some cases, the conductive layer serves to conduct electrochemical signals and establish an electrical connection with electronic devices upon insertion. In some cases, it is composed of conductive materials such as one or more types of metals (gold, silver, copper, ruthenium, rhodium, platinum, bismuth, tungsten, iron, titanium, rhenium, osmium, iridium), doped ceramics (indium tin oxide, aluminum-doped zinc oxide, fluorine-doped tin oxide), carbonaceous materials (graphite, carbon black, carbon nanotubes, graphene, reduced graphene oxide), and conductive polymers (poly(3,4-ethylenedioxythiophene)polystyrene sulfonate), polypyrrole, polyaniline, polythiophene, poly(p-phenylene), polyphenylene diamine, or 2D materials (e.g., MoS2, WSe2, VO2).

[0069] In some cases, the layer may include an electrically semiconductive material with added impurities to alter its resistive properties. For example, the electrically semiconductive material may include a semiconductive ink, such as, but not limited to, amorphous carbon, carbon black, graphite, carbon nanotubes, and / or graphene. In some embodiments of the method, for example, the electrode pattern may include carbon fiber segments dispersed within a conductive or semiconductive material.

[0070] The test strip may include a permeable protective layer to protect the underlying layer from mechanical or chemical damage. The protective layer may comprise one or a combination of polymers (Nafion, chitosan, methyl or ethyl cellulose, polyvinyl chloride, polyurethane, silicone, polytetrafluoroethylene, polyolefins, polyesters, polycarbonates, copolymers, polyvinylidene fluoride, polymethyl methacrylate, and polysulfides). The sensor may also include a protective layer composed of polymeric materials such as Nafion, chitosan, ethyl cellulose, polyvinyl chloride, polyvinyl alcohol, polyethylene glycol, polyacrylamide, polyacetate, polyvinylpyrrolidone, or polyethylene oxide.

[0071] The test strip may include an anti-interference layer comprising one or more of the following: metals, mediators (ferrocene and ferrocene derivatives, ferrocyanide, ferrocyanide, Prussian blue, quinone, tetrathionyl fulvalene, organic dyes (methylene blue, Meldora blue), osmium or ruthenium complexes), negatively / positively charged molecules or polymers (Nafion, polyfluoroalkane, fluororubber, chitosan, polyethyleneimine, polyurethane, polystyrene sulfonate, polyvinyl sulfate, polyvinyl alcohol, polyvinyl chloride). In some embodiments, the fluororubber comprises one or more copolymers of vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, and perfluoromethyl vinyl ether. In some embodiments, the fluororubber includes the addition of ethylene and propylene to the copolymer. In some embodiments, the fluororubber is an elastomer.

[0072] The sensor may include an insulating layer made of a dielectric material. The insulating layer partially covers the test strip to define and limit the exposed area, and may be deposited or attached to a previous layer. The insulating layer may be made of a non-conductive material and may have specific desired properties, such as waterproof, rigid, transparent, or antibacterial.

[0073] The test strip may include a conditioning layer to adjust the hydrophilicity and electrostatic charge of the electrode. The conditioning layer may contain one of a combination of polymers and surfactants.

[0074] In some cases, test strips can be reusable (e.g., capable of multiple readings). Test strips can be reused at least approximately 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 times or more. Test strips can be reused at least approximately 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 days or more. Test strips can be disposable (e.g., non-reusable). For example, test strips can be discarded after each use. Test strip reading devices can be reusable. For example, test strip reading devices can be configured to allow the removal of used test strips and the replacement of new test strips into the test strip reading device. In this way, test strip reading devices can be reused as housings and interfaces for multiple different test strips. Test strip reading devices can be reused for at least approximately 2, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, or more test strips. Reusable test strip reading devices offer advantages such as lower long-term costs, increased complexity and capability with onboard sensors and computing power, and user convenience. In some cases, test strip reading devices may not be reusable. For example, a test strip reading device may be configured to accept only a single test strip, and when that test strip is used up, it is discarded along with the test strip. Disposable test strip reading devices offer lower upfront costs, smaller form factor, etc.

[0075] In some cases, the test strip reading device can be configured to allow the removal of the test strip after testing the sample. For example, the test strip may not be permanently attached to the test strip reading device. The test strip can interface with the test strip reading device via, for example, electronic leads (e.g., spring pins, conductive clamping leads, etc.). The test strip reading device may include portions configured to hold the test strip in place and facilitate connection between the test strip and the electronics of the test strip reading device. In some cases, the test strip reading device can be configured to accept test strips (e.g., after removing expired test strips). In this way, the test strip reading device can be reused for multiple test strips, as described elsewhere herein.

[0076] The test strip reading device can be configured to read information from test strips. Information can be read via a physical connection (e.g., via a contact point). Information can also be read wirelessly (e.g., via a near-field communication module). This information may include, for example, the type of test strip (e.g., biomarkers identifying the test strip), the batch number or lot number of the test strip, the remaining number of measurements the test strip can be used for, the health condition of the test strip (e.g., whether defects are present or absent in the test strip), the cleanliness of the test strip (e.g., whether impurities are present or absent on the test strip), the quality of the test strip (e.g., another quality the test strip possesses), etc., or any combination thereof.

[0077] manufacture This electrochemical sensor layer technology may include disposable sensors for non-invasive and painless detection of specific analytes associated with disease or health performance metrics. In some aspects, the disclosed electrochemical sensors may be used on device patches that can be fabricated or integrated onto various substrates, such as, but not limited to, paper, fabric, flexible and / or stretchable plastics, or stretchable elastomer films. In some cases, the electrochemical sensor layer test strip is a single-use strip. In some cases, the electrochemical sensor layer test strip is designed for multiple uses. Exemplary electrochemical sensor layers of this technology can be manufactured using various techniques, such as, but not limited to, printing processes such as screen printing, roll-to-roll printing, inkjet printing, and / or offset printing. This technology can provide painless, disposable, non-invasive testing as an alternative to disposable strips for detecting chemicals in the blood.

[0078] Each layer of the test strip can be deposited on top of a substrate or other layer using various thin-film and thick-film methods, including electrodeposition, sputtering, physical and chemical vapor deposition, screen printing, transfer printing, dip coating, spraying, spin coating, doctor blade coating, inkjet printing, drop casting, or micro-dot patterning. The formed layer can be attached to a previous layer by cold pressing, hot pressing, bonding, curling, and embedding. Patterning methods include, but are not limited to, direct deposition or printing, mask deposition or printing, mask etching, laser ablation, laser cutting, mechanical abrasion, or mechanical cutting.

[0079] In some aspects, a method of producing an epidermal biosensor includes forming an electrode pattern on a coated surface of a paper-based substrate to form an electrochemical sensor, the electrode pattern comprising conductive and electrically insulating materials configured in a specific design layout. In some embodiments, an adhesive sheet is additionally present on the surface of the electrochemical sensor layer having the electrode pattern. In some instances, the adhesive sheet is capable of adhering to the skin. In some cases, it is configured to include a coating on the outer surface of the adhesive sheet. In some cases, after removing the coating, the paper-based substrate from the electrochemical sensor layer exposes the electrode pattern. In some embodiments of the method, the formation may include screen printing, aerosol deposition, or inkjet printing the electrode pattern onto the coated surface of the paper-based substrate.

[0080] For example, conductive materials may include conductive inks, such as, but not limited to, gold, platinum, nickel, copper, silver, and / or silver chloride. Electrically insulating materials may include non-conductive inks, such as, but not limited to, PET, PS, PE, and / or PTFE. In some examples, the electrode pattern may include an electrically semiconductive material. For example, the electrically semiconductive material may include semiconductive inks, such as, but not limited to, amorphous carbon, carbon black, graphite, carbon nanotubes, and / or graphene. In some embodiments of the method, for example, the electrode pattern may include carbon fiber segments dispersed within a conductive material or an electrically semiconductive material.

[0081] Electrode assembly Electrochemically based sensors can be used to detect chemicals, substances, and biological materials (e.g., organisms) by using transducers to convert detection events into signals for processing and / or display. Biosensors can use biological materials as biosensitive components, such as biomolecules including enzymes, antibodies, nucleic acids, etc., and living cells. For example, molecular biosensors can be configured to recognize target reagents using specific chemical properties or molecular recognition mechanisms. Biosensors can use transducer elements to convert signals generated by the detection of analytes by biosensitive components into different signals that can be processed by optical, electronic, or other means. For example, transduction mechanisms can include physicochemical, electrochemical, optical, piezoelectric, and other transducer devices.

[0082] In some embodiments, the non-invasive electrochemical sensor layer of the disclosed technology includes an anode electrode group and a cathode electrode group. Each group includes an electrochemical sensor layer electrode assembly comprising a working electrode, a counter electrode, and / or a reference electrode. The working electrode, counter electrode, and / or reference electrode together constitute an electrochemical sensor layer electrode assembly for sensitive chemical detection. In embodiments of a two-electrode configuration of the electrochemical sensor, for example, in addition to the working electrode, a second electrode may operate as both a reference electrode and a counter electrode. In embodiments of a three-electrode configuration of the electrochemical sensor, for example, in addition to the working electrode, one electrode may operate as a reference electrode, and another electrode may operate as a counter electrode. In some embodiments, for example, the working electrodes of the cathode and / or anode are modified with specific acceptors such as enzymes, ion carriers, and / or other reagents to achieve selective detection of the desired chemical analyte. Examples of ion carriers include, but are not limited to, sodium ion carriers (e.g., monensin, monensin, etc.), fluoride ion carriers (e.g., fluorides, lanthanum fluoride, aluminum fluoride, etc.), chloride ion carriers (e.g., tridecylmethylammonium, quaternary ammonium, etc.), and any combination thereof.

[0083] In some embodiments, the electrochemical sensor layer is electrically coupled to one or more circuitry or electronic devices. For example, the electrochemical sensor layer may include an electrode interface assembly comprising individual or separate conductive conduits disposed on a substrate, the conductive conduits being electrically coupled to anodic and cathode electrode assemblies. In some cases, the substrate may include flexible and / or stretchable properties. The individual or separate conduits are configured to electrically couple the electrochemical sensor layer electrodes of the anodic and cathode electrode assemblies to external circuitry or electronic devices capable of electrically stimulating the electrochemical sensing electrodes and capable of individually stimulating the electrodes for their respective operation.

[0084] In some embodiments used for alcohol detection, a three-electrode system for the electrochemical sensor layer electrode assembly is preferred. For glucose detection, however, the electrochemical sensor layer electrode assembly may include a two-electrode system (e.g., a working electrode and a counter / reference electrode) because the current measured as a function of glucose concentration is relatively low, making a two-electrode system sufficient for glucose detection. For example, in the case of alcohol detection, the alcohol concentration in biological fluids (e.g., sweat) can be relatively high, and therefore the measured current is higher, thus allowing the use of a three-electrode system.

[0085] In some embodiments, the sensor uses a closely spaced or interdigitated electrode design, ensuring a small interelectrode distance (<1 mm), which allows ion pathways between two or more electrodes to be used for signal transduction when in contact with a fingertip. In some embodiments, the first and second electrodes, as well as the first and second current collectors, are arranged in the same direction. In some embodiments, the first electrode may be a working electrode, and the second electrode may be a reference / counter electrode. The first electrode (e.g., working electrode) and the second electrode (e.g., reference / counter electrode) are arranged alternately, and adjacent first and second electrodes are spaced apart from each other by a predetermined distance. In some embodiments, the distance between adjacent first and second electrodes may be about 1 mm. In one embodiment, the distance between adjacent first and second electrodes is less than 1 mm. In another embodiment, the distance between adjacent first and second electrodes is greater than 1 mm. In one embodiment, the first electrode (e.g., working electrode) and the second electrode (e.g., reference / counter electrode) are interdigitated and arranged radially. In another embodiment, the first electrode (e.g., working electrode) and the second electrode (e.g., reference / counter electrode) are interdigitated and arranged parallel to each other. In some embodiments, the first electrode (e.g., working electrode) and the second electrode (e.g., reference / counter electrode) are arranged concentrically. In some embodiments, the electrodes in the sensor are radially aligned. In some embodiments, the interdigitated electrodes are concentric.

[0086] In some embodiments, the gel-free sensor includes a plurality of first electrodes extending along a first direction, a plurality of second electrodes extending along the first direction, a first current collector coupled to the plurality of first electrodes, and a second current collector coupled to the plurality of second electrodes. In one example, the first and second electrodes are arranged alternately in a second direction. In one example, the first direction is perpendicular to the second direction. In some embodiments, the first current collector is connected to one end of each first electrode, and the second current collector is connected to one end of each second electrode. In some embodiments, the first electrode can be used as a working electrode, and the second electrode can be used as a reference / counter electrode. In some embodiments, the first electrode can include a PEDOT:PSS-Prussian blue (PB) cathode, and the second electrode can include a poly(3,4-ethylenedioxythiophene)polystyrene sulfonate (PEDOT:PSS) anode. In some embodiments, the first and second electrodes are solid-state interdigitated electrodes printed on a styrene-isoprene-styrene block copolymer (SIS) substrate. In some embodiments, the solid-state interdigitated electrodes are modified with glucose oxidase (GOx) enzyme, which selectively reacts with glucose in fingertip sweat for subsequent detection. In some embodiments, the first and second electrodes extend in the same direction (e.g., a second direction) and are arranged alternately at predetermined distances. In one example, the predetermined distance between adjacent first and second electrodes provides an ion pathway. In some embodiments, the predetermined distance is less than 1 mm.

[0087] In some aspects, the electrochemical sensor layer includes a substrate formed of an electrically insulating material. In some aspects, a first electrode is formed on a substrate of a conductive material, a second electrode is disposed on the substrate of a conductive material and separated from the first electrode by a spacer region, the first and second electrodes are capable of maintaining a redox reaction to generate an electrical signal, and a first electrode interface component and a second electrode interface component are formed on the substrate and electrically coupled to the first and second electrodes respectively via conductive conduits, wherein, when in contact with skin and electrically coupled to one or more circuits via the first and second electrode interface components, the device is operable to detect substances in the local environment of the skin or wearable item.

[0088] In another aspect, a method of manufacturing an electrochemical sensor layer includes depositing conductive ink on an electrically insulating substrate to form two or more electrodes that are adjacent to and separated from each other, and conduits connected to each electrode. The deposition includes printing ink onto a first template placed on the substrate, the first template including patterned regions configured in a design for two or more electrodes and conduits to allow ink transfer to the substrate, and the first template inhibiting ink transfer to areas outside the patterned regions; curing the conductive ink; depositing electrically insulating ink on the substrate to form an insulating layer exposing the two or more electrodes, the deposition including printing the electrically insulating ink onto a second template placed on the substrate, the second template including printed regions configured in a second design to allow ink transfer to the substrate, the second template inhibiting ink transfer to areas outside the printed regions; and curing the electrically insulating ink.

[0089] Embodiments of the method may optionally include one or more of the following features. In some embodiments, for example, the substrate may include a paper substrate. For example, the paper substrate may include an upper layer and a base paper layer, the upper layer including a release agent coated on the base paper layer and configured to peel off to remove the paper substrate. For example, curing may include applying at least one of heat or ultraviolet radiation to the deposited ink on the substrate. In some embodiments, for example, the method may include forming an electrically semiconductive layer on at least one of two or more electrodes by printing an ink of an electrically semiconductive material onto a third template placed on the substrate, the third template including a printing area configured in a first design for at least one of the two or more electrodes, the printing area allowing ink transfer on the paper substrate and the third template inhibiting ink transfer to areas outside the printing area; and curing the electrically semiconductive ink. In some embodiments, for example, the method may include dispersing carbon fibers in conductive ink.

[0090] Functionalization and multiplexing detection In some cases, sensors are designed for multiplexing to detect multiple biomarkers. In some cases, multiplexing electrodes for detecting multiple biomarkers and physiological signals are on the same sensor. In some cases, the sensor device includes a plurality of first electrodes extending in a first direction, a plurality of second electrodes extending in the first direction, a first current collector coupled to the plurality of first electrodes at one end of each first electrode, and a second current collector coupled to the plurality of second electrodes at one end of each second electrode.

[0091] In some embodiments, the test strip includes multiple electrode arrays, each including a first electrode and a second electrode discussed in this patent document. In one example, different electrode arrays 142, 144, and 146 can be used to detect different biomarkers: biomarker 1, biomarker 2, and biomarker 3.

[0092] Embodiments of the device may optionally include one or more of the following features. For example, in some embodiments of the device, at least one of the first or second electrodes may include an enzyme catalyst and an electroactive redox medium, the electroactive redox medium facilitating electron transfer between the electrode and the active site of the enzyme catalyst configured to maintain a redox reaction. In some embodiments, for example, the device may include a conductive underlayer, respectively on a substrate and beneath each of the first and second electrodes, providing separation between the first and second electrodes.

[0093] In some embodiments, for example, the working electrodes of the cathode and / or anode are modified with specific acceptors such as enzymes, ion carriers, and / or other reagents to achieve selective detection of the desired chemical analyte. The electrochemical sensing layer includes at least an electrochemical transducer with biorecognition functionality, such as enzymes (glucose oxidase, glucose dehydrogenase, alcohol oxidase, alcohol dehydrogenase, lactate oxidase, lactate dehydrogenase, cholesterol oxidase, uricase, urease, ascorbic acid oxidase, horseradish peroxidase, catalase, tyrosinase, creatinine deiminase, amylase, glutamate oxidase, xanthine oxidase, bilirubin oxidase, hydroxybutyrate dehydrogenase, hydroxybutyrate oxidase, acetoacetate dehydrogenase), ion carriers, antibodies, nucleic acids, aptamers, molecularly imprinted polymers, and microorganisms.

[0094] Electrodes can be functionalized with various chemical / electrochemical transducers, such as enzymes (e.g., lactate oxidase, lactate dehydrogenase, glucose oxidase, glucose dehydrogenase, bilirubin oxidase, uricase, urease, alcohol oxidase, alcohol dehydrogenase, tyrosinase, catalase), catalysts (e.g., platinum, ruthenium, palladium, rhodium, silver), redox media (Prussian blue, Meldora blue, methylene blue, indigo carmine, 2,2'-bipyridine, 1,4-naphthoquinone, tetrathiofulvalene, tetracyanoquinone dimethane, ferrocene), antibodies, ion-selective membranes, silver / silver chloride mixtures, molecularly imprinted membranes, or aptamers, for sensing biomarkers. In some embodiments, the electrode is functionalized with glucose. In some embodiments, the electrode is functionalized with lactate. In some embodiments, the electrode is functionalized with alcohol.

[0095] An exemplary device's glucose sensor includes an anode group and a cathode group, each group comprising: an Ag / AgCl electrode serving as a counter / reference electrode; and a printable Prussian blue transducer (selected in this exemplary embodiment due to its high selectivity for hydrogen peroxide (a detectable product of the GOx enzymatic reaction)). In some embodiments, glucose is extracted in the cathode group, and the working electrode of the cathode group (e.g., modified with a GOx enzyme) is operable to selectively detect glucose. In other embodiments where the analyte comprises a negatively charged component (e.g., lactate), the analyte is extracted in the anode group, and the working electrode of the anode group can be modified with a reagent (e.g., a catalyst, such as lactate oxidase (LOx enzyme) in the case of lactate) to selectively detect the analyte. In an exemplary embodiment for glucose detection, chitosan is used as a polymer matrix for immobilizing the enzyme on the transducer surface. However, in some embodiments, different biocompatible polymers other than chitosan may be used. In some cases, care should be taken to ensure proper contact between the skin and the sensor during reverse iontophoresis to effectively extract glucose and avoid skin irritation. For example, this can be achieved by uniformly coating each group with a biocompatible agarose gel layer to cover all electrodes. The resulting glucose sensor can be easily applied to the skin, adhering and conforming to the contours of the epidermis.

[0096] In some embodiments, the sensor device may include additional sensors for measuring resistance and / or temperature. The sensors may include additional closely spaced or interdigitated electrodes for physiological sensing, having physical transducers such as thermal resistance, thermoelectric, piezoresistive, piezoresistive, piezocapacitive, photovoltaic, physically adsorbed, or chemically adsorbed materials that sense physical properties such as temperature, skin moisture levels, or pressure.

[0097] electronic devices In some cases, the test strip reading device of this disclosure is an electronic device. In some embodiments, the electronic device includes a circuit board and a mechanical housing. In some embodiments, the circuit board includes a microcontroller, a signal generation and processing chip such as a potentiostat, a data storage chip, and a connector into which the test strip can be inserted. In some embodiments, it may include wireless transmission capabilities (e.g., Bluetooth, LTE, 5G), an antenna, a display panel or indicator lights, electrical or mechanical buttons, and a power source such as a battery. In some embodiments, the mechanical housing includes a casing to protect the circuit board and the test strip. In some cases, the test strip reading device may have a power life of at least about 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, 18 months, 24 months, or more (e.g., the length of time the test strip reading device has operating power supplied to it, battery life). In some cases, the test strip reading device may not always be on (e.g., it may be in a switched-off state (e.g., to save power)). In some cases, the test strip reading device is always on (e.g., to provide a faster latency during measurement).

[0098] In some embodiments, the circuit board controlled by the microcontroller unit can perform various types of electrochemical measurements, including open-circuit voltage measurement, chronopotentiometric method, chronoamperometric method, chronocoulometric method, cyclic voltammetry, differential pulse voltammetry, square wave voltammetry, linear sweep voltammetry, AC impedance spectroscopy, and DC internal resistance measurement.

[0099] The circuit board can store and process raw signals from electrochemical measurements. The raw signals can be converted into concentrations of target analytes using pre-programmed algorithms and user-input calibration data. The algorithms may include two-point or single-point linear regressions using user-input calibration data obtained from another biomarker monitoring device, such as a blood glucose monitor or continuous glucose monitor. Such algorithms can be personalized and individualized for different fingers.

[0100] The memory chip can store the number of times the test strip has been used, the raw signal, the processed data, the measurement time, and personalized and individualized calibration data.

[0101] The circuit board can use wired or wireless transmission to transmit stored information to auxiliary devices, such as computers or smartphones, or to cloud-based data centers for data analysis and visualization. A system (e.g., including a test strip reading device) can include a computer processor operatively coupled to the test strip reading device. For example, the computer processor may be contained within the test strip reading device. In another example, the computer processor may be external to the test strip reading device (e.g., in another device local to the test strip reading device, in a cloud computing server, etc.). The computer processor can be configured to use the test strip reading device or data from the test strip reading device to determine the properties of a sample (e.g., blood glucose levels, the presence or absence of an analyte, etc.). For example, the computer processor may provide commands to the test strip reading device to perform measurements on the sample. In another example, the computer processor may receive data generated by the test strip reading device and use that data to determine the properties of the sample.

[0102] The mechanical housing may include a movable cover that allows a finger to access the test strip by opening the cover. The cover can be closed after use to protect the test strip. The cover may include a replaceable wipe or scraper to remove sweat residue after touch. The mechanical housing may include a replaceable wiper so that the user can wipe their finger before touching the test strip. The mechanical housing may include mechanical guides to define the exact location of finger contact.

[0103] In some cases, the test strip reading device may include a cover. In some cases, the mechanical housing may include a cover. The cover may be positioned to protect the uncovered surface of the test strip (e.g., from abrasion, dust, water, accidental contact, etc.). For example, in the closed position, the cover may cover the test strip, thereby preventing accidental contact. The cover may include the same material as the body of the test strip reading device. For example, a polymer test strip reading device may include a polymer cover to provide lightweight protection. The cover may include a different material from the body of the test strip reading device. For example, a metal cover may be used to provide additional protection against damage to the test strip. The cover may slide relative to the test strip reading device. For example, to expose the test strip, the cover may slide along the test strip reading device. The cover may be attached to the test strip reading device via a hinge. For example, the cover may flip up to expose the test strip. The cover or the test strip reading device may include one or more sensors configured to determine the open or closed state of the cover. For example, the cover may include a magnet, and the test strip reading device may include a magnetic sensor to determine the proximity of the cover to the test strip reading device. In this example, when the cover is closed, the magnet may be very close to the magnetic sensor, thereby generating a signal that the cover is closed. Examples of sensors include, but are not limited to, position sensors (e.g., potentiometers, etc.), optical sensors, magnetic sensors, electrical sensors, and any combination thereof. The presence of a lid sensor enables the system to remind the user to close the lid after use if the user forgets to do so, and to eliminate erroneous readings that occur when the lid is closed.

[0104] Electronic devices may include optical or electrical sensors to measure various physiological and physical signals from the fingers during sweat sensing. Other physiological and physical signals include, but are not limited to, temperature, moisture level, sweat gland density, sweating rate, transdermal water loss rate, pressure, hydration level, heart rate, and blood oxygen level. One or more sensors may include one or more thermistors, infrared sensors, thermocouples, resistance temperature detectors, moisture meters, capacitive sensors, hygrometers, cameras, piezoelectric sensors, capacitive pressure sensors, electrical sensors (e.g., electrocardiogram sensors), ultrasound sensors, skin conductance sensors, impedance sensors, and any combination thereof.

[0105] Electronic devices can use such physical or physiological signals in algorithms to correct the conversion from raw signals to biomarker concentrations.

[0106] Electronic devices may include optical, capacitive, or ultrasonic fingerprint scanners to identify the user and which finger was used for non-invasive sweat monitoring.

[0107] In some embodiments, the disclosed biosensor device includes an integrated electronic backbone for powering the sensor, and signal processing and wireless communication units on the sensor platform, enabling the collection of intermittent data from diabetic patients and the performance of large-scale glucose monitoring across different patient populations. Exemplary biosensing platforms can be readily used for non-invasive monitoring of other chemical markers present in interstitial fluid, as well as for transdermal drug delivery.

[0108] Figure 6 A diagram of an exemplary sensor device of the disclosed technology is shown. Figure 7 A block diagram of an exemplary test bar is shown. (As follows) Figure 8 As shown, a sensor device system may be part of a kit that may include a power supply 802 (e.g., a battery), a current test strip notch 804, a test strip (sensor signal acquisition unit) 803, and a data processing unit 801 capable of signal processing and communication (e.g., to external devices). The data processing unit may include a processor for processing data and a memory that communicates with the processor to store the data. For example, the processor may include a central processing unit (CPU) or a microcontroller unit (MCU). The memory may include and store processor-executable code that, when executed by the processor, configures the data processing unit to perform various operations, such as receiving information, commands, and / or data, and processing information and data. To support the various functions of the data processing unit, the memory may store information and data, such as instructions, software, values, images, and other data processed or referenced by the processor. For example, various types of random access memory (RAM) devices, read-only memory (ROM) devices, flash memory devices, and other suitable storage media may be used to implement the storage function of the memory unit.

[0109] The data processing unit may include input / output (I / O) units and / or output units, which can be connected to, for example, external interfaces, data storage sources, or display devices. Furthermore, various types of wired or wireless interfaces compatible with typical data communication standards can be used for communication via the data processing unit through the wireless transmitter / receiver unit 605. These interfaces include, but are not limited to, Universal Serial Bus (USB), IEEE 1394 (FireWire), Bluetooth, IEEE 802.111, Wireless Local Area Network (WLAN), Wireless Personal Area Network (WPAN), Wireless Wide Area Network (WWAN), WiMAX, IEEE 802.16 (Microwave Access Global Interoperability (WiMAX)), 2G / 3G / 4G / LTE / 5G cellular communication methods, Near Field Communication (NFC), Ultra Wideband, and parallel interfaces. For example, the test strip reading device may include a USB port (e.g., USB A port, USB B port, USB C port, etc.). The USB port can provide data transfer and power delivery to the test strip reading device. For example, plugging a test strip reader into a USB port on a computing device (e.g., a computer, cellular phone, etc.) provides power from the computing device and access to data generated by the test strip reader by the computing device's processor. The I / O of the data processing unit can also interface with other external interfaces, data storage sources, and / or visual or audio display devices to retrieve and transmit data and information that can be processed by the processor, stored in memory units, or presented on the output units of external devices. For example, an external display device can be configured to communicate with the data processing unit via I / O, and the I / O may include visual display devices, audio display devices, and / or sensing devices, such as smartphones, tablets, and / or wearable technology devices.

[0110] In some cases, the test strip reading device may include a display. Examples of displays include, but are not limited to, liquid crystal displays, light-emitting diode displays, electronic ink displays, and any combination thereof. The display may be configured to show the user information such as the number of tests remaining on the test strip, when to touch the test strip and for how long, error messages, and the results of analysis performed on the user's skin. In some cases, the test strip reading device may include one or more physical buttons. One or more physical buttons may allow operation of the test strip reading device without coupling the test strip reading device to an external computer processor. For example, one or more physical buttons may enable the user to input commands into the test strip reading device to perform analysis on the user's skin. In some cases, the physical buttons are mechanical buttons, digital buttons, capacitive buttons, and any combination thereof. In some cases, the test strip reading device may not include any physical buttons. In some cases, the test strip reading device may include a sensor configured to determine whether a user's finger is present on the test strip in the test strip reading device. For example, a pressure-activated switch, a pressure sensor, etc., may determine whether a user's finger is present on the test strip. The presence of the user's finger (e.g., determined by the sensor) may initiate a measurement (e.g., a biomarker measurement). For example, a pressure sensor can detect the presence of a user's finger, and a test strip reading device can determine the concentration of biomarkers in the user's sweat. In some cases, the sensor can terminate the reading. For example, when the user removes their finger from the test strip, the sensor can stop measuring using the test strip. The test strip reading device may include a haptic feedback module. For example, the haptic feedback module can provide vibration feedback when the user activates and deactivates the test strip reading device. The test strip reading device may include an audio module. The audio module may include one or more audio input devices (e.g., microphones) and / or one or more audio output devices (e.g., speakers). The audio module can be configured to interface with the user to provide, for example, instructions or feedback regarding the use of the test strip reading device. The audio module can be used to activate or deactivate the device.

[0111] In some embodiments, for example, the electronic system may be contained within a housing that is electrically connected to the sensor device via electrical contact pads on the substrate of the sensor device, the electrical contact pads being interconnected to the electrodes of the sensor device. Figure 6 In such an embodiment, the contained electronic system may be a portable device that is attached to and detached from the device (e.g., attaching and detaching the test strip from a retainer notch in the device), and carried by the user for easy access to the next test, e.g., placed in the user's pocket, wallet, etc. Figure 6The sensor device can make electrical contact with a portable device via multiple connections, including pressure contacts, magnetic contacts, solder contacts, etc. The incorporated electronic system can be wired or wirelessly connected to a user's mobile communication or computing device (e.g., smartphones, tablets, wearable computing devices such as smart glasses, smartwatches, etc., and / or laptops or desktop computers). An exemplary incorporated electronic system can be powered, operated, and retrieve acquired physiologically relevant electrical signals from the sensor device.

[0112] This disclosure relates to wearable technology devices, such as smartwatches, health bands, fitness bands, and smartphones, and combinations thereof, which can help their wearers prevent and / or treat physiological conditions such as dehydration, stress, fatigue, muscle fatigue, infection, and / or depression by instructing users when to perform a sweat test. Therefore, wearable devices include attachable wearable devices that attach to the body (e.g., wrist, neck, ankle, waist, ear, etc.) and carried devices (e.g., mobile phones). Thus, the various embodiments described herein are adapted to monitor and determine when a person should test their sweat based on the occurrence of one or more specific physiological conditions. Because some physiological conditions can lead to severe weakness or even life-threatening situations, enabling wearable devices to provide such functionality allows users of the technology not only to quickly identify certain physiological conditions but also, for example, to take remedial action as instructed by the wearable device. Furthermore, by providing users with instructions on when to perform a sweat test, the guesswork that could cost the user money is eliminated. For example, performing a sweat test when prompted can prevent unnecessary sweat tests and the associated costs. As described in detail below, such aspects can be facilitated by various GUIs and other software features running on one or more of various devices, including wearable technology devices (or simply "wearable devices"), web servers, and other devices. These broad aspects of this disclosure are described below with reference to various specific examples. That is, those skilled in the art will readily understand that the specific examples described are merely examples intended to inform and guide those skilled in the art regarding the broad range of features they can then implement in numerous ways using only ordinary knowledge and skills in the art.

[0113] In some embodiments, the disclosed biosensor device includes an integrated electronic backbone for powering the sensor, and signal processing and wireless communication units on a flexible wearable sensor platform, capable of collecting continuous data from diabetic patients and performing large-scale glucose monitoring across different patient groups. The exemplary biosensing platform can be readily used for non-invasive monitoring of other chemical markers present in interstitial fluid, as well as for transdermal drug delivery.

[0114] The embodiments of the subject matter and functional operation described in this patent document can be implemented in various systems, digital electronic circuits, or computer software, firmware, or hardware, including the structures disclosed in this specification and their structural equivalents, or combinations thereof. Embodiments of the subject matter described in this specification can be implemented as one or more computer program products, i.e., one or more modules of computer program instructions encoded on a tangible and non-transitory computer-readable medium for execution by or control of the operation of a data processing apparatus. The computer-readable medium can be a machine-readable storage device, a machine-readable storage substrate, a memory device, a composition of materials that implements machine-readable propagation signals, or combinations thereof. The term "data processing apparatus" includes all means, devices, and machines for processing data, such as a programmable processor, a computer, or multiple processors or computers. In addition to hardware, the apparatus may also include code that creates an execution environment for the computer program in question, such as code constituting processor firmware, a protocol stack, a database management system, an operating system, or combinations thereof.

[0115] A computer program (also known as a program, software, software application, script, or code) can be written in any programming language, including compiled or interpreted languages, and can be deployed in any form, including as a standalone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program does not necessarily correspond to a file in a file system. A program may be stored in a part of a file that stores other programs or data (e.g., one or more scripts stored in a markup language document), in a single file dedicated to the program in question, or in multiple coordinating files (e.g., a file that stores portions of one or more modules, subroutines, or code). A computer program may be deployed to execute on a single computer or on multiple computers located in one place or distributed across multiple locations and interconnected by a communication network.

[0116] The processes and logic flows described in this specification can be executed by one or more programmable processors, which execute one or more computer programs to perform functions by manipulating input data and generating outputs. The processes and logic flows can be executed by dedicated logic circuitry, and the device can be implemented as dedicated logic circuitry, such as an FPGA (Field-Programmable Gate Array) or an ASIC (Application-Specific Integrated Circuit).

[0117] Processors suitable for executing computer programs include, for example, general-purpose microprocessors and special-purpose microprocessors, as well as any one or more processors in any type of digital computer. Typically, a processor receives instructions and data from read-only memory or random access memory, or both. The key components of a computer are the processor for executing instructions and one or more memory devices for storing instructions and data. Typically, a computer will include one or more mass storage devices (e.g., magnetic disks, magneto-optical disks, or optical disks) for storing data, or be operatively coupled to receive data from or transfer data to one or more mass storage devices for storing data, or both. However, a computer does not necessarily need to have such devices. Computer-readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media, and memory devices, including semiconductor memory devices such as EPROM, EEPROM, and flash memory devices. The processor and memory may be supplemented or incorporated into special-purpose logic circuitry.

[0118] In some cases, a test strip reading device may include a microprocessor. The microprocessor may be configured to interface with the test strip to acquire measurements from it. For example, the microprocessor may be electrically coupled to the test strip via one or more leads, and may instruct the transmission of electrical signals along one or more leads. The microprocessor may be configured to receive analog data from the test strip and convert it into digital data. For example, analog electrical measurements from the test strip may be converted into digital values ​​before being provided to a computer processor for processing.

[0119] In some cases, the test strip reader can be configured to attach to a computing device. For example, the test strip reader may have a smaller form factor than the computing device. Examples of computing devices include, but are not limited to, mobile phones, watches, wearable devices (e.g., pedometers, smartwatches, etc.), laptop computers, and any combination thereof. The test strip reader can be attached to the computing device in a manner in which the test strip reader can also be operatively connected to the computing device. For example, the test strip reader can be inserted into a physical port of the computing device. In another example, the test strip reader can be connected to the computing device to which it is attached via a wireless connection. In some cases, the test strip reader can be reversibly attached to the computing device. For example, the test strip reader can be attached to the computing device using one or more hooks, loops, adhesives, etc. In some cases, the test strip reader can be permanently attached to the computing device. For example, the test strip reader can be integrated into the body of the computing device. In another example, the test strip reader can be attached to the computing device using epoxy resin, etc.

[0120] In some cases, test strip reading devices may have a volume of up to approximately 50, 40, 30, 25, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03, 0.02, 0.01 or less cubic centimeters. In some cases, the test strip reading device may have a volume of up to about 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 cubic centimeters or more. The test strip reading device may have a volume within the range defined by any two of the foregoing values. The test strip reading device may be configured to guide a user's finger or fingertip to the test strip. For example, the test strip reading device may include ridges, contours, protrusions, etc., oriented to help the user find the test strip and correctly position their finger on the test strip for accurate measurement. In some cases, ridges, contours, protrusions, or combinations thereof may be fingertip-shaped contours. The shape of the test strip reading device may be configured to position the user's finger on the test strip when the user holds it in their hand. For example, a test strip reading device can be shaped such that when held naturally in the user's hand, one of the user's fingers is positioned above the test strip.

[0121] Test strip reading devices can have shape factors similar to credit cards (e.g., narrow, with a credit card-like size), keychains (e.g., having a maximum size of up to about 5, 4, 3, 2, 1 inches or less, configured to be attached to a keychain), rings (e.g., configured to be worn on a user's finger), etc. Test strip devices can be integrated into mobile computing platforms (e.g., laptop computers). For example, a laptop computer may include a test strip holder and a cover configured to protect the test strip. Test strip reading devices can be configured to be integrated into mobile phone housings. For example, a mobile phone housing may be configured to hold the mobile phone and the test strip. In this example, the mobile phone may be communicatively coupled to the test strip reading device. Test strip reading devices can be configured to be covered by a portion of the mobile phone housing. For example, a portion of the mobile phone housing may form a cover for the test strip reading device. Test strip reading devices may include fixing portions (e.g., adhesives, magnets, hooks, and rings) configured to attach the test strip reading device to the mobile phone housing. For example, the test strip reading device may be attached to a user-supplied mobile phone housing. Test strip reading devices may be permanently attached to the mobile phone housing. The test strip reading device does not need to be permanently attached to the mobile phone casing.

[0122] 1. Detection method Sweat is a non-invasive, recyclable biofluid containing abundant trace amounts of health-related biomarkers. Sweat sensors have shown great potential in monitoring physiological health (e.g., hydration), disease diagnosis and management (e.g., diabetes and gout), and therapeutic drug monitoring (e.g., pain management). However, the presence of the skin as a mechanical barrier prevents uninterrupted access to this information-rich biofluid, thus requiring triggering systems (i.e., physical exercise, thermal stimulation, or iontophoresis) to provide continuous access to sweat samples. In contrast to this strong, active stimulation approach, the natural sweating pathway has demonstrated great potential for achieving simple, easy, and continuous acquisition of sweat for chemical analysis. Utilizing the high density (approximately 400 glands cm⁻²) of eccrine sweat glands and the resulting high rate of sweating, finger-touch-based biosensors for detecting key sweat biomarkers (e.g., glucose, vitamin C, and cortisol) have recently been reported.

[0123] In some embodiments, this document provides a non-invasive method for detecting analytes from a fingertip, the method comprising: inserting a test strip of any of the preceding claims into a device of any of the preceding claims; placing a portion of a user’s skin in contact with the test strip; and obtaining a reading of the analyte from the test strip reading device.

[0124] In some embodiments, a non-invasive method for monitoring an analyte from a fingertip includes: receiving a sample from a user's skin on a test strip of any of the preceding claims, inserted into a device of any of the preceding claims, through skin contact with a test strip; generating an electrical signal based on an electrochemical measurement of the analyte using a solid-state electrochemical sensor; measuring the concentration of the analyte in the sample based on the electrical signal; calculating the systemic concentration of the analyte in the user from the concentration of the analyte in the sample using the device; and providing the systemic concentration of the analyte on a display of the device.

[0125] In some embodiments, the method includes, at 610, obtaining a sweat sample from a sweat sample taken from an individual's finger onto a sweat-permeable layer of the device using the device disclosed in this patent document. Figure 5 ), using signals from the sensors disclosed in this patent document to acquire multiple measurements of the analyte level ( Figure 7 For each of the multiple measurements of the analyte level, a measurement of the analyte concentration in the individual's blood is obtained. At 602, the power parameter, multiplier parameter, and intercept parameter of the correlation between the obtained measurement of the analyte concentration in the individual's blood and the obtained measurement of the analyte level in the individual's sweat are obtained. At 602, the new measurement of the analyte level in the individual's sweat is converted into an estimate of the analyte concentration in the individual's blood using the power parameter, multiplier parameter, and intercept parameter.

[0126] Exemplary methods for determining the concentration of an analyte in an individual's blood, based on some embodiments of the disclosed technology. In some embodiments, the method includes obtaining a sweat sample from a sweat sample taken from an individual's finger and deposited onto a sweat-permeable layer of the device using the device disclosed in this patent document; acquiring multiple sets of measurements of the level of the analyte in the individual's sweat using signals from the device disclosed in this patent document, wherein the sweat is collected by the device from an individual's finger in contact with the sweat-permeable layer of the device; for each set of measurements of the level of the analyte in the individual's sweat, obtaining a corresponding set of measurements of the concentration of the analyte in the individual's blood; for each set of measurements of the level of the analyte in the individual's sweat, obtaining values ​​of a linear slope parameter and an intercept parameter for the correlation between the measurements in that set and the measurements in the corresponding set of measurements of the concentration of the analyte in the individual's blood; determining the average value of the linear slope parameter and the average value of the intercept parameter for the sets of measurements of the level of the analyte in the individual's sweat; and determining the concentration of the analyte in the individual's blood based on the determined average value of the linear slope parameter and the determined average value of the intercept parameter.

[0127] glucose test In some embodiments, a touch-based, non-invasive sweat fingertip glucose test comprises two steps: collecting sweat via a touch membrane (which covers an enzyme biosensor) and using the biosensor to perform amperometric detection of the products of a biocatalytic reaction. Figure 5 The high density of sweat glands in the fingertip ensures sufficient biofluid volume for reliable and repeatable glucose measurements. Direct contact between the fingertip and the sweat permeation layer (…) Figure 5 When the fingertip is in contact with the sweat-permeable layer for a minimal amount of time (e.g., about 1 minute), sweat is collected from the fingertip. From the direct contact between the fingertip and the sweat-permeable layer, a minute amount of sweat fluid is drawn in (collected) and transferred through the layer, where the collected sweat diffuses to the recognition layer (i.e., the modified and / or unmodified electrodes of the electrochemical sensor), where an enzymatic reaction occurs to detect parameters of the analyte in the sweat, which can be processed to determine parameters of the analyte in the blood (discussed elsewhere in this disclosure).

[0128] This painless touch-based glucose sensor represents a promising non-invasive approach to improving diabetes monitoring by increasing the frequency of glucose testing. However, analyzing glucose in sweat is a challenging task. Sweat glucose levels can fluctuate depending on the method used to collect the sweat. For example, sweat collected during exercise may underestimate glucose levels, while iontophoresis may overestimate them due to glucose buildup on the iontophoresis gel. Furthermore, contamination from skin components such as bacteria, moisturizers, and even glucose itself can affect measured glucose values. Glucose concentrations in sweat range from 0.01 to 1.11 mM, significantly lower than blood concentrations (240 mM).

[0129] A fingertip-touch glucose sensor ensures user-friendly sweat collection because it does not involve the movement or chemical stimulation of sweat glands. The technology disclosed in this patent document uses a “personalized” mathematical approach that significantly improves the sweat-blood glucose correlation and overall accuracy of glucose testing. This simple, one-time personal calibration, following a single training session of the system, addresses individual variations in sweat rate and skin properties through a unique sweat-to-blood conversion algorithm. The brief personal system training involves blood-verified sweat signals to estimate each person’s mean personal slope (K) and intercept (Io) to obtain a personalized sweat-to-blood conversion factor. Such initial training and processing significantly improves the Pearson correlation coefficient (Pr) to 0.95, reflecting a substantial improvement in the accuracy of the overall mean absolute relative difference (MARD), with 100% of paired points falling within the A+B region of the Clarke Error Grid (CEG). These substantial improvements are achieved without requiring additional sensors and complex microfluidic networks to correct and normalize the results. Following this one-time personal training of the system, the results can be obtained through methods such as… Figure 5The finger-based test shown estimates accurate blood glucose levels directly from an individual's sweat glucose response over a period of several weeks, relying solely on their sweat signal without requiring blood sampling. A single blood calibration is recommended once or twice a month. These single-cycle measurements are analyzed by software that filters out outliers and updates existing individual parameters.

[0130] Detailed studies have shown that using both the individual intercept and slope is significantly more accurate than using the slope alone. This greatly improved correlation is achieved even when the values ​​of the slope and intercept vary substantially between subjects. In some embodiments, the slope value corresponds to the rate of fingertip sweating, while the intercept reflects multiple factors based on individual skin properties and sweat composition. This simple mathematical processing can be easily integrated into software (e.g., in a handheld meter or smartphone app) to provide built-in individual calibration for autonomous estimation of sweat-based glucose concentration (SG). The method presented in this paper calibrates the subject's individual equation based on an initial blood-validated sweat response. Once this personalized transformation is obtained, glucose levels can be estimated directly and reliably from sweat measurements without the need for blood fingertip verification. Single blood calibrations are recommended once or twice a month. This single-period measurement result is analyzed by software that filters out outliers and updates existing individual parameters. By taking into account inter-individual variability, the new method provides an efficient standardization of the sweat glucose response, thereby significantly improving inter-personal sweat-blood correlation parameters and potentially being applied to the monitoring of other sweat biomarkers.

[0131] Then, a personalized algorithm is used to convert the electrochemical signal into blood glucose levels, taking into account individual skin properties and sweating rates. Following successful embodiments of the touch-based sweat collection / electrochemical detection protocol sensor, the disclosed techniques can be implemented in some embodiments to provide a mathematical approach for correlating sweat glucose responses with blood glucose concentrations. This personalized sweat-to-blood conversion algorithm involves measuring the fingertip sweat glucose response and calibrating these current values ​​using blood glucose levels from a commercial blood glucose meter. Measurements are taken daily at the same time. Sweat and blood glucose levels are measured 20 minutes before and after meals. An optimized protocol for fingertip sweat analysis is strictly followed. First, patients are asked to clean their index finger with a damp paper towel and wait 3 minutes; next, they are asked to touch the sensor for 1 minute. Subsequently, the sweat signal is measured for 60 seconds at a fixed potential of -0.2 V using chronoamperometry. Therefore, mechanical cleaning with water is used due to potential interactions with surfactant residues in soap. This cleaning protocol is followed by an optimal contact time of 1 minute. Calibration plots are analyzed daily, and the mean slope and intercept are calculated.

[0132] Cortisol test In some embodiments, the disclosed techniques can be implemented to provide an effective novel stress-free cortisol sensing platform that allows for rapid, reliable, and simple detection of cortisol in sweat via fingertip touch. The disclosed techniques can be implemented in some embodiments to develop novel stress testing platforms utilizing this natural sweat sampling method, relying on highly scalable screen-printed electrodes modified with a selective MIP recognition layer. Compared to motion-based contrast sweat cortisol sensors, collecting natural sweat via simple fingertip touch ensures that only endogenous cortisol levels are measured. To achieve one-step, rapid, repeatable, highly sensitive, and selective cortisol sensing, an electropolymerized polypyrrole (PPy) MIP electrode was synthesized in the presence of cortisol as a template and Prussian blue (PB) as an embedded redox probe, thus eliminating the need for complex labeling procedures or external redox probes. Cortisol is subsequently eluted from the membrane via the peroxidation of PPy, which induces a structural change in the polymer, releasing the template cortisol molecules.

[0133] This change was confirmed using various surface characterizations and molecular simulations. Template elution produces a surface recognition cavity complementary to the shape and size of the target cortisol molecule. The incorporation of PB within the MIP PPy network results in a “built-in” electrochemical signal probe, eliminating the need for an external redox probe and thus significantly simplifying in vivo testing compared to common MIP sensors based on such solution-phase redox probes. The resulting user-friendly cortisol sensor integrates MIP recognition and a built-in PB transduction element, thus enabling chronoamperometry (CA) dependent on the PB oxidation current. The selective binding of cortisol within the imprinted cavity leads to the blockage of the PB electron transfer pathway, resulting in a reduction in the PB oxidation current. The degree of this current reduction reflects the concentration of sweat cortisol and can therefore be used as an analytical signal. This change in current was confirmed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Rapid, label-free CA cortisol sensing was achieved by incorporating a built-in PB redox transducer within the imprinted polymer and systematically optimizing experimental parameters. In some cases, the test takes only about 3 minutes, which is more than ten times faster than conventional cortisol measurements, thus offering a significant advantage in capturing cortisol levels that fluctuate dramatically in response to acute stimuli. This rapid and simple cortisol testing platform enables easy and stress-free cortisol sensing to track circadian cortisol level variations. This sensing platform can be used to capture changes in cortisol levels during physical stimuli, which alter endogenous cortisol levels and are important for indicating injury, fatigue, and dehydration / malnutrition. Therefore, the simplicity and speed of touch-based fingertip sweat analysis coupled with label-free MIP-based electronic detection enables dynamic stress response analysis for personalized healthcare and the management of individual stress and mental health.

[0134] Dopa test The disclosed technology, which can be implemented in some embodiments, provides personalized medication monitoring for PD patients. Its core lies in the dynamic, non-invasive tracking of levodopa (L-Dopa) levels in sweat after ingestion of a standard pill formulation. Utilizing naturally thermoregulated sweat samples, a finger-touch L-Dopa biosensor based on some embodiments of the disclosed technology can monitor the dynamic curve of sweat L-Dopa after ingestion of a standard anti-Parkinson's disease drug including L-Dopa-carbidopa (100:25 mg). In some embodiments, the current L-Dopa signal difference is measured at 10-minute intervals shortly after drug ingestion. In some cases, the signal shows an increase in sweat reaching its peak level, followed by a decrease to its background level. In some cases, the obtained sweat samples show similar pharmacokinetic curves to capillary blood samples, with negligible lag times (approximately 10 minutes).

[0135] L-Dopa analysis relies on transferring natural sweat to an electrode modified with an immobilized tyrosinase, whereby sweat-derived L-DOPA is oxidized to dopaquinone through its reaction with the immobilized tyrosinase. The enzymatically generated dopaquinone is then electrochemically reduced back to L-Dopa at an applied potential of -0.3 V, and the resulting amperometric signal correlates with the dynamic fluctuations in L-Dopa levels. This non-invasive, rapid, and simple touch-based procedure shows considerable promise in guiding dose adjustments for PD patients by capturing real-time fluctuations in sweat L-DOPA levels.

[0136] The disclosed methods, apparatus, and systems can be used to provide fingertip L-Dopa biosensors. L-Dopa detection can begin by (a) touching the sensor with an index finger, and (b) transferring L-Dopa-containing natural sweat from the skin surface to the electrode surface, wherein electrochemical measurements are performed on the tyrosinase-immobilized electrode, such as... Figure 5 As shown.

[0137] The disclosed techniques can be implemented in some embodiments to provide levodopa monitoring using touch-based sensors. The time course of one cycle of levodopa detection in fingertip sweat may include measuring the current before touch (2 minutes), touching (2 minutes), measuring after touch (2 minutes), and waiting for the next cycle (4 minutes). Levodopa detection is achieved by coupling the oxidation of levodopa catalyzed by tyrosinase (catecholase activity) with the subsequent electrochemical reduction of the corresponding quinone product—dopaquinone—at a low potential. The resulting reaction cycle not only enhances sensitivity by amplifying the resulting current signal but also prevents electrode fouling by inhibiting the spontaneous polymerization of unstable quinone molecules. Tyrosinase is immobilized on the surface of a screen-printed carbon electrode and then crosslinked with glutaraldehyde to prevent enzyme leaching.

[0138] The sensor's performance in tracking levodopa pharmacokinetics was characterized by administration of L-Dopa / C-Dopa (100:25 mg) pills (a common oral medication for PD patients) to healthy subjects. Carbidopa (C-Dopa) is an amino acid (Dopa) decarboxylase inhibitor, and its co-administration with levodopa improves drug bioavailability. Carbidopa is an orthodiol compound that can be oxidized by tyrosinase, thus interfering with the detection of the target levodopa. The selectivity of the sensor was challenged by detecting L-Dopa / C-Dopa at a concentration ratio of 4:1 (similar to the ratio in the pill). In some cases, selectivity tests were performed to detect interference from carbidopa in the signal from the levodopa detection. In some cases, selectivity tests indicated minimal interference from carbidopa, consistent with achieving accurate and reliable levodopa detection.

[0139] Typical measurements of targeted levodopa after pill ingestion can be performed every 10 minutes. The optimal time course for a single 10-minute cycle of the in vivo levodopa sensing protocol includes an initial 2 minutes of recording background current on the electrodes (without fingertip touch), followed by 2 minutes of placing the index finger on the gel (covering the working electrode) during which sweat diffuses onto the electrode surface, then stepping the potential to -0.3 V and recording the current signal for 2 minutes. After each cycle, subjects are asked to wait 4 minutes before starting the next cycle. The levodopa current signal begins to increase 10 minutes after administration, reaches its peak value at 30 minutes, and then declines back to its background level nearly an hour after administration. Touch-based levodopa sensors can successfully track changes in levodopa sweat levels. While plasma is the "gold standard" matrix for levodopa treatment monitoring, this analytical method relies on a centralized LC-MS instrument. To further confirm the reliability of the developed touch-based sweat levodopa detection scheme, the feasibility of data validation between sweat and blood samples was investigated to confirm that the peak time distribution of sweat closely matches the corresponding blood levodopa concentration (with a short 10-minute time delay).

[0140] In some embodiments, the disclosed technology is implemented to simultaneously provide drug detection methods and devices. Driving under the influence of illicit or legal drugs such as marijuana and alcohol is one of the major safety concerns because these substances have a strong synergistic effect. Therefore, there is a need for rapid on-site testing of such substances to reduce the risk of road accidents. Thus, the disclosed technology can facilitate the accurate and rapid discrete detection of drugs using a finger sweat sensor combined with mathematical methods. The disclosed technology can be used as a personal safety system for vehicle ignition, where the finger sweat sensor is directly integrated into the vehicle ignition device, including but not limited to the on / off button, car key, etc. Multiple sweat drug molecules can be detected simultaneously for drug screening and identification. Software for personalized quantification of such drugs can include a drug database for identifying substances in sweat. The disclosed technology not only helps advance this important and much-needed self-monitoring application to improve safety, but also enables law enforcement officers to screen drivers during traffic stops, addressing the growing problem of drug-impaired driving.

[0141] In some cases, the method may include a test strip reading device that provides a test strip (e.g., a test strip as described elsewhere herein). For example, the test strip may include a solid-state electrochemical sensor layer and a conductive layer. The test strip may contact a portion of a subject's skin. The solid-state electrochemical sensor layer and the conductive layer can be used to generate electrical measurements based on biomarkers from a portion of the subject's skin. The electrical measurements can be used to determine the nature of the subject's biomarkers.

[0142] The nature of a biomarker can be as described elsewhere herein (e.g., a subject's blood glucose level). For example, the method can be a non-invasive method for determining a subject's blood glucose level. The determination of the nature of a biomarker can be performed without pre-calibration or standardization. For example, the raw output of the test strip reader can be used to determine the nature of the biomarker without applying pre-calibration. In some cases, the test strip reader has already been calibrated once for multiple tests. For example, the determination of the nature of a biomarker for a given individual may not include calibration, but a global calibration of the test strip reader can be performed. In this way, individual determination can be faster while maintaining accuracy. In some cases, calibration measurements can be used to determine the nature of a biomarker. For example, the test strip reader unit can be calibrated.

[0143] In some cases, additional sensors, such as those described elsewhere herein, can be used to provide additional data points in the measurement of biomarkers. For example, skin roughness or moisture content measurements can be used to help accurately determine the nature of a biomarker. In this example, moisture content can be used to standardize biomarker readings for different conditions on a user's finger. In some cases, the use of additional sensors of this disclosure can enable calibration-free measurements of the nature of biomarkers. For example, using a combination of sensor data, the nature of a biomarker can be determined without the need for a separate calibration curve for the user's biomarker. In this way, the test strip reading device of this disclosure can be used on subjects without prior calibration, which is useful in emergency situations, such as when prior calibration may not be available.

[0144] In some cases, the cover attached to the test strip reader can be opened to expose the test strip before it is touched. For example, a user can open the cover to access the test strip. In some cases, the test strip is reusable, as described elsewhere in this document (e.g., at least about 15 times).

[0145] definition Unless otherwise defined, all technical terms, symbols, and other technical and scientific terms or expressions used herein are intended to have the same meaning as commonly understood by one of ordinary skill in the art to which the claimed subject matter pertains. In some cases, terms having a commonly understood meaning are defined herein for clarity and / or for reference at any time, and the inclusion of such definitions herein should not necessarily be construed as indicating a material difference from the commonly understood meaning in the art.

[0146] Throughout this application, various embodiments may be presented in a range format. It should be understood that the range format is merely for convenience and brevity and should not be construed as a rigid limitation on the scope of this disclosure. Therefore, a range description should be considered to have all possible subranges of the specific disclosure and the individual numerical values ​​within that range. For example, a range such as 1 to 6 should be considered to have specific disclosed subranges such as 1 to 3, 1 to 4, 1 to 5, 2 to 4, 2 to 6, 3 to 6, etc., and the individual numbers within that range, such as 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.

[0147] As used in this specification and claims, unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” include plural indicators. For example, the term “sample” includes multiple samples, including mixtures thereof.

[0148] As used herein, the term “about” means that the difference from the quantity stated is no more than 10%.

[0149] The terms “determine,” “measure,” “evaluate,” “assess,” “determine,” and “analyze” are often used interchangeably in this document to refer to the form of measurement. These terms include determining the presence of an element (e.g., detection). These terms can include quantitative, qualitative, or a combination of quantitative and qualitative determinations. Assessments can be relative or absolute. “Detecting presence” can, depending on the context, include not only determining the presence of a substance but also determining the quantity present.

[0150] The terms “subject,” “individual,” or “patient” are often used interchangeably in this document. A “subject” can be a biological entity containing expressed genetic material. A biological entity can be a plant, animal, or microorganism, including, for example, bacteria, viruses, fungi, and protozoa. A subject can be a tissue, cell, or progeny of a biological entity obtained in vivo or cultured in vitro. A subject can be a mammal. A mammal can be a human. A subject may be diagnosed or suspected of being at high risk for a disease. In some cases, a subject may not necessarily be diagnosed or suspected of being at high risk for a disease.

[0151] The chapter titles used in this article are for organizational purposes only and should not be construed as limiting the topics described. Example

[0152] The following examples are included for illustrative purposes only and are not intended to limit the scope of this disclosure.

[0153] Example 1: Touch-based sweat glucose monitoring system A touch-based sweat glucose monitoring system quantifies glucose (sugar) in fresh, natural sweat from the fingertips and converts it into corresponding blood glucose levels after personalized calibration. The disclosed technology can be implemented in some embodiments to provide a unique solid-state interdigital electrode transducer for direct touch-based glucose monitoring without requiring any sweat extraction mechanism. Unlike earlier studies based on sweating stimulated by exercise or iontophoresis, which reported low correlation with blood glucose, current use of natural sweating, combined with single-day personalized calibration, provides high accuracy in predicting blood glucose levels. With the attractive features of this novel, user-friendly, non-invasive biosensing method and its high-quality data, the disclosed technology can be implemented in some embodiments to achieve non-invasive glucose monitoring, which can become an important component of diabetes self-care.

[0154] Figure 6 Example sensor devices for measuring biomarkers (e.g., glucose in sweat) in biological fluids are illustrated based on some embodiments of the disclosed technology. Components of the sensor device are given in Table 1. In some embodiments, the method includes placing the sensor system in contact with the subject's skin, using, for example...Figure 5 The sensor system shown measures biomarkers in biofluids (e.g., sweat) from a subject's skin. The sensor system can be composed of, for example... Figure 6 The sweat glucose meter shown and such Figure 7 The test strip is shown in Table 2. The system works by utilizing the fact that glucose in capillary blood can diffuse through sweat glands and be expelled through natural perspiration from the fingertips. The test strip has a retainer notch for the user to hold the strip without touching sensor 701. A plastic sensor retainer is depicted in 702. The test strip is insulated, as shown in 703. Sensing occurs in sensing area 704. The test strip is functionalized with the enzyme GOx and a small current can be detected when it reacts with glucose in natural sweat. The intensity of this current can be correlated with the sweat glucose level via an initial two-point calibration. The touch-based sweat glucose sensing system displays the sweat glucose level 602 and then stores it in system memory. In some embodiments, the glucose sensing system is part of a kit that includes a touch-based sweat glucose monitor 801 with a notch for inserting the test strip 804, four sensors 803, and a pre-installed battery 802. In some cases, the kit also includes a manual with user instructions.

[0155] Table 1

[0156] Table 2

[0157] In some embodiments, the touch-based sensing system includes display monitors 601-605. The display monitors are designed to display information 602 regarding the level of an analyte measured in the biological fluid. The display monitors have other indicators, such as a sensor life indicator 603. In other cases, the display monitors display information about battery life 604, or about connectivity to a Bluetooth source 605, or date / time 601.

[0158] The sensor system includes an instrument that is opened by the user by pressing a key until a welcome screen appears. In other cases, the system includes an instrument that is opened by sliding the sensor cover from the standby position 901 to the test position 902. The sensor instrument includes up / down buttons 607 and 609 for changing digits and a middle button 608 for jumping to the next digit / next step. At the end of the setup, the user presses the MID (middle) button 608 to confirm that the time and date are correct, or presses the DWN (down) button 609 to reset the settings.

[0159] The device prompts users to set up a personalized calibration profile before first use of the meter. This requires two sets of blood glucose measurements at two different blood glucose levels—one fasting and one one hour after a meal. For each set of measurements, the user performs one finger prick measurement using a commercial-grade blood glucose meter and one measurement using a touch-based sweat glucose monitor system. The sensor meter is designed for personal calibration to each individual and to a specific finger. The sensor meter is designed to be used with the same finger used for the personal calibration of the blood glucose monitoring system. The sensor meter is designed to measure glucose values ​​between 40 and 400 mg / dL, and the user must calibrate using two different calibration items above 20 mg / dL.

[0160] Before performing the finger prick test, the user washes their hands and uses a glucose test strip that is not expired and has been stored correctly. After performing the glucose measurement test as instructed, the user accurately enters the results into the system calibration profile based on the system touch.

[0161] To complete the calibration profile, the user must press their index finger on the touch-based sensor to measure glucose levels until the screen indicates completion, and then press the MID button to confirm. A second set of measurements is performed when glucose levels have changed significantly (>20 mg / dL). The user again presses their index finger on the touch-based sensor to measure glucose levels until the screen indicates completion, and then presses the MID button to confirm.

[0162] The sensor meter requires the user to clean and dry their selected index finger before use. The sensor meter has a cover; the user pushes the cover to the open position using their selected index finger and then presses the sensing area to begin the test. A click sound is heard when sufficient pressure is applied. The sensor meter has a cover that the user closes after measurement. Results are displayed on the screen and stored in the meter's memory. If the glucose test result is below 20 mg / dL, the sensor meter indicates to the user that this may indicate hypoglycemia and stores the result in the mobile application. A glucose test result above 600 mg / dL may indicate hyperglycemia (high blood sugar) or a result above the measurement range. High results are stored in the meter. On the mobile application, it will be saved as a test result >600 mg / dL.

[0163] In some cases, the test strip can be used 30 times. After each measurement, the remaining number of uses will be displayed in the lower left corner of the screen. After the test strip has been used 30 times, the sensor meter will indicate to the user that the test strip needs to be replaced. If the sensor has been used more than 30 times, a sensor change notification will be displayed. 603 To replace the sensor, the user pulls out the test strip using the retainer notch. 610 The user inserts the new test strip into the test strip insertion port and pushes it until it is fully inserted. If it is not fully inserted, an insertion notification will be displayed on the screen until a new sensor is detected.

[0164] In some embodiments, the electronic system may include a display to present the analyzed data to a user. The sensor system stores 200 glucose measurement results. A non-invasive electrochemical sensor layer is connected to an external electronic system, which may be portable and / or wearable on the user. The electronic system powers the electrochemical sensor layer and analyzes the acquired sensor signals (e.g., detected current, voltage, etc.) to generate data about the analyte, such as chemical concentration. Information can be wirelessly transmitted from the electronic system to a user computing device, such as a smartphone, tablet, wearable computing device such as smart glasses, smartwatch, etc., and / or a laptop or desktop computer. The electronic system can connect to such a user computing device via physical contact (e.g., wired) or wirelessly using RF or Bluetooth communication or other wireless communication technologies. Bluetooth technology allows users to wirelessly send their readings to a mobile device, where they can plot their results.

[0165] Example 2: Sensor Manufacturing Figure 1 An exploded schematic diagram of the sensor's structure is shown. This disclosure can be implemented in some embodiments to provide a solid-state touch sensor capable of frequent, accurate, and non-invasive glucose monitoring. The sensor has the ability to withstand conditions such as... Figure 2 A shows a substrate subjected to chemical and mechanical processing. In some cases, photolithography / patterning techniques are used to fabricate the substrate. Figure 2 B.

[0166] The electrochemical sensor layer on the test strip can be fabricated using layer-by-layer screen printing. For example, in one instance, the sensor was customized using multiple inks. In one instance, the sensor was first coated with electrochromic poly(3,4-ethylenedioxythiophene)polystyrene sulfonate (PEDOT:PSS) ink, then coated with silver ink used for interconnection, and then coated with an insulating resin composed of SEBS. The PEDOT:PSS ink was formed using a mixture of inks prepared with 1 g of PEDOT:PSS slurry, 0.2 mL of toluene, 0.15 mL of DBSS (75 mg / mL in DI water), and 0.0135 mL of the fluorosurfactant FS-65. To prepare the PEDOT:PSS-PB ink, a similar composition can be used, with an additional 20 mg of PB powder added per 1 g of mixture. In one instance, a stretchable silver ink was synthesized using a combination of silver flakes, toluene, and SEBS mixed in a weight ratio of 4:2.37:0.63. The ink was homogenized by mixing it in a dual asymmetric centrifugal mixer, for example, at 1900 RPM for 5 minutes. The insulating resin was prepared by dissolving SEBS in a toluene solution (4:10 by weight). The solution was then mixed at 1900 RPM for 20 minutes or until the SEBS was completely dissolved.

[0167] Following ink preparation, a flexible substrate for printing fingerprint sensors is fabricated. The surface of the substrate can be mechanically, chemically, or physically treated to alter its surface roughness, hydrophobicity, dielectric constant, and electrostatic charge to improve adhesion and compatibility with sweat sensing. Processing techniques include one of acid or alkaline chemical etching, plasma etching, electroplating, abrasion, laser ablation, sputtering, heating, and physical or chemical vapor deposition. For example, polyethylene terephthalate substrates can be acid-etched by immersing them in a 1M HCl bath at 80°C for 1 hour. In some cases, the substrate can then be rinsed with water and dried to remove residual chemicals. In other cases, the substrate can undergo a 20-minute ozone plasma treatment to remove chemical contaminants and enhance its adhesion to subsequent deposited layers. The substrate is composed of one or more types of plastic, ceramic, or natural materials, such as polyethylene, polypropylene, polyethylene terephthalate, polyester, polyimide, polydimethylsiloxane, alumina, silicon, and paper.

[0168] In some embodiments, a 1000µm SIS layer is formed on top of a PET plastic sheet. The thin layer is dried at 60°C for 30 minutes. The printed electrode pattern (e.g., electrode area 0.02 cm²) is designed in the software. 2 ), and transfer it to a stainless steel sheet (e.g., 12 x 12 inches). 2On the substrate, etching was used to create a metal template. The electrochemical system, consisting of a working electrode and a reference electrode, was screen-printed using an MPM-SPM semi-automatic screen printer. The printing process involved first printing the reference electrode on the SIS substrate using PEDOT:PSS ink, followed by a curing step at 120°C for 30 minutes. Next, the working electrode was printed using PEDOT:PSS-PB ink, with similar drying conditions applied after the electrode printing. Subsequently, a silver interconnect pattern was printed on top of the electrode system, followed by a curing step at 90°C for 15 minutes. The interconnects were insulated using SEBS resin. Finally, the insulator was dried at 90°C for 10 minutes to obtain the printed electrode. The electrode could then be modified by drop-casting a mixture of 6 µL glucose oxidase (20 mg / mL in PBS, 0.1 M, pH 7.3) and 3 µL glutaraldehyde (1% in DI water) onto the exposed electrode surface. After modification, the electrode was stored overnight in a refrigerator at 4°C.

[0169] In one example, the electrochemical sensing layer may comprise a combination of cofactors, mediators, stabilizers, polymers, or plasticizers. For example, in some embodiments: graphite, toluene, acetone, ethanol, glutaraldehyde, glucose, glucose oxidase (GOx), silver foil, potassium chloride (KCl), sodium chloride (NaCl), anhydrous sodium phosphate, Prussian blue, and sodium dodecylbenzenesulfonate (DBSS) are used to fabricate interdigitated electrodes based on some embodiments of the disclosed technology. Based on some embodiments of the disclosed technology, a styrene-ethylene-butene-styrene (e.g., SEBS G1645) triblock copolymer is used to fabricate the interdigitated electrode. In one example, based on some embodiments of the disclosed technology, a screen-printable PEDOT:PSS paste is used to fabricate the interdigitated electrode.

[0170] In addition to the electrochemical sensing layer, the sensor also includes an insulating layer, an anti-interference layer, a protective permeable layer, and a conditioning layer. Each layer of the test strip is deposited on top of a substrate or other layer using various thin-film and thick-film methods, including electrodeposition, sputtering, physical and chemical vapor deposition, screen printing, transfer printing, dip coating, spraying, spin coating, doctor blade coating, inkjet printing, drop casting, or micro-dot patterning. The formed layers are attached to previous layers by cold pressing, hot pressing, bonding, curling, and embedding. Each layer of the test strip is patterned individually or together into the desired shape for optimal sweat contact and signal transduction.

[0171] Example 3: Characterization of in vitro sensors The touch-based glucose sensor was characterized in vitro using 0.1 M PBS (pH 7.3) and ascorbic acid (100 µM). The in vitro characterization of the touch-based glucose sensor included the characterization of the sensor's selectivity and reproducibility (Figures 3-4). Figure 3A(i) Characterization of the sensor without an anti-interference layer is shown in the presence and absence of ascorbic acid, including (i) 2-electrode CV and (ii) CA at different potentials from -0.2 V to 0.6 V. Figure 3B (i) shows the characterization of a sensor with an anti-interference layer in the presence and absence of ascorbic acid, including (i) 2-electrode CV and (ii) CA at different potentials from -0.2 V to 0.6 V.

[0172] Furthermore, in the absence of an anti-interference layer ( Figure 3A (ii) and the existence of an anti-interference layer ( Figure 3B In case of (ii), selective testing was performed in PBS by adding 100 µM ascorbic acid (AA), acetaminophen (AP) and uric acid (UA). Figure 3A (ii) shows the selectivity of the sensor: the CA response of the sensor in PBS (blank) and after the addition of 1 mM glucose before substrate treatment. Figure 3B (ii) shows the selectivity of the sensor: the CA response of the sensor in PBS (blank) and after the addition of 1 mM glucose following substrate treatment.

[0173] For these repeated touch-based measurements, highly reproducible CA signals were observed, resulting in an RSD of 4.8% using the substrate processing procedure. Figure 4B In contrast, it was 15.3% without substrate treatment. Figure 4A The highly reproducible current signal exhibits a low RSD of 3.9% (n=20), revealing good repeatability for frequent, repeated measurements. Figure 4C ).

[0174] Example 4: Monitoring and Validation of Cortisol in the Diurnal Cycle The disclosed techniques can be implemented in some embodiments to provide methods and devices for monitoring sweat biomarkers. Personalized processing of touch-based fingertip sweat analysis provides simplified and accurate tracking of combinations of key sweat biomarkers such as levodopa, cortisol, alcohol, lactate, ketones, or uric acid, as well as illicit drugs or tetrahydrocannabinol (THC). For example, tracking fluctuations in cortisol levels is crucial for understanding the body's endocrine response to stress stimuli. Traditional cortisol sensing relies on centralized laboratory settings, while wearable cortisol sensors are limited to slow and complex assays. The disclosed techniques can be implemented in some embodiments to provide a simple touch-based sensor for rapid cortisol detection. In one embodiment of this technique, the entire assay can take approximately 3 minutes, which is extremely important for capturing transient and rapid changes in cortisol levels. The sensor easily collects natural sweat from the fingertip and introduces it into a polypyrrole layer imprinted with cortisol, in which a Prussian blue redox probe is embedded. Figure 5 This is an illustration of an experimental setup used to visualize sweat on a fingertip when the sensor is pressed. The process is tense and lengthy, involving sweat extraction. Correlating sweat biomarker values ​​with corresponding blood values ​​is a current challenge in the sweat sensor industry; the novel method disclosed in this paper makes it possible to accurately estimate blood concentrations while considering inter-individual variability.

[0175] The performance of the novel cortisol sensor was first evaluated by monitoring changes in endogenous cortisol levels during the diurnal cycle. Studies have shown that cortisol levels are correlated with a diurnal rhythm, with concentrations higher in the morning, decreasing during the day, and finally reaching lower levels at night. Semi-continuous dynamic tracking of these cortisol levels is quite important for assessing an individual's chronic stress levels. Therefore, the daily variations in the response of the touch-based sweat cortisol sensor were monitored and validated. Cortisol levels in five patients were measured using fingertip sweat at 7 a.m. and 5 p.m. on the same day, and validation was performed using immunoassays on pilocarpine-stimulated sweat samples.

[0176] As an example, optimized touch and incubation times were used, and cortisol signals were acquired using a portable device with a test strip sensor modified for cortisol detection. For subjects using a finger-based cortisol sensor, 86 to 200 x 10⁻⁶ were observed. -9Significant differences were observed in m-cortisol levels, and the current-induced cortisol responses of the three patients showed considerable variation in the morning / evening tests. Background signal was measured using the sensor surface, followed by sweat cortisol measurements in the morning (red curve) and evening (blue curve). In some cases, the new sensor was used to record each response. Data from the sensor were correlated between sweat cortisol concentrations estimated via the fingertip MIP sensor and those estimated via the corresponding immunoassay (Pearson correlation coefficient r = 0.96). Following sweat validation testing, the new sweat finger sensor was successfully used to monitor morning and evening cortisol levels in other patients, showing significant differences in concentrations during these periods. The rapid and convenient use of the finger cortisol sensor was demonstrated by monitoring cortisol levels in several patients throughout the day. For this purpose, sensor responses were recorded every 2 hours over a 12-hour period from 7:00 AM to 7:00 PM. A gradual decrease in sweat cortisol levels was observed in all patients during the morning and evening measurements.

[0177] Attempting sweat stimulation during physical activity results in a mixture of chemically and exercise-induced sweat, clearly indicating the need for effortless sweat cortisol sensing, as exercise-induced cortisol can influence endogenous cortisol levels. During this semi-continuous cortisol monitoring period, patients engaging in daily activities including routine exercise (including 30 minutes of indoor cycling) showed an increase in sweat cortisol levels immediately after exercise, which decreased to endogenous levels within 2 hours. Therefore, to assess and validate exercise-induced stress stimulation, a sweat-inducing protocol should be used immediately after routine exercise.

[0178] Example 5: Multiplexing of biomarkers for detection In some embodiments, the application of the data processing method may be combined with a number of biosensors, including but not limited to levodopa biosensors modified by tyrosinase or non-enzymatic sensors modified by voltammetry, lactate biosensors modified by lactate oxidase (or other recognition elements), cortisol biosensors modified by molecularly imprinted polymerization (MIP) (or other recognition elements), ketone body biosensors using sensors (or other recognition elements) modified by p-hydroxybutyrate dehydrogenase, glucose biosensors using glucose oxidase (or other recognition elements), THC sensors using sensors (or other recognition elements) modified by nanoparticles, CNTs or MIPs, sensors for illicit drugs such as cocaine, sensors for illicit drugs such as cocaine using bare carbon electrodes (or other recognition elements), and alcohol sensors using enzyme alcohol oxidase (or other recognition elements).

[0179] For example, in addition to detecting cortisol as described in the foregoing embodiments, the disclosed techniques can be implemented in some embodiments to provide a data processing method for correlating the sweat analyte response to ketone biomarkers in natural passive perspiration with its blood concentration. A p-hydroxybutyrate dehydrogenase-modified sensor biosensor is used to measure sweat ketones. After a defined amount of time following contact with the skin, the collected sweat reaches a recognition layer where the analyte is measured. As described above, the working electrode of the screen-printed 3-electrode system is enzyme-modified for detecting ketones and cortisol. Sweat is collected from the fingertips during a 1-minute touch period following proper handwashing. After collection, the sweat ketone signal is obtained by chronoamperometry. The signal is obtained twice daily for one week.

[0180] After data acquisition, a personalized correlation equation can be determined. For this purpose, several days of data are collected and validated using appropriate methods. For example, commercial urine analysis can be used to validate the determination of sweat ketones. Urine samples are collected and analyzed before each measurement in the validation step. After data collection, the linear slope and intercept obtained each day are averaged, and a personalized general equation is derived to directly convert signal intensity into blood concentration. As described above, for each day of analysis, the linear correlation between two points (sweat and urine ketones) is obtained, and the average slope and intercept are calculated for the user. These personalized values ​​take into account individual sweat parameters, such as sweat rate and composition. The sensor signal is then directly converted into blood ketone values ​​and cortisol levels (obtained as described in an earlier example) using the personalized general equation. Therefore, various embodiments of the features of the disclosed technology can be based on the above disclosure, including the examples and embodiments listed above.

[0181] Example 6: Test bar reading device Figures 10A-10B An example of a credit card shape factor test strip reader 1000 is shown. The credit card shape factor test strip reader may include a cover 1010 covering a test strip 1020. The credit card shape factor test strip reader may be disposable. For example, the credit card shape factor test strip reader may not be configured with a removable test strip. The credit card shape factor test strip reader may include a wireless power delivery or wireless data transmission module as described elsewhere herein. For example, the credit card shape factor test strip reader may not include ports or other interface points. The credit card shape factor test strip reader can provide a low-cost and compact test strip reader.

[0182] Figures 11A-11CAn example of a key fob shape factor test strip reading device 1100 is shown. A cover 1110 can be positioned to protect the test strip 1120 and is movable to expose the test strip. A ring 1130 can be configured to interface with a chain, belt, etc., thereby providing the ability to secure the key fob shape factor test strip reading device. In some cases, the test strip can be removed from a slot 1150 1140 and replaced with a new test strip. In this way, the key fob shape factor test strip reading device can be reused for multiple test strips. As described elsewhere herein, the key fob shape factor test strip reading device may include a battery configured to power the key fob shape factor test strip reading device. In some cases, the key fob shape factor test strip reading device can be discarded once the battery is no longer inoperable (e.g., the battery may be non-replicable).

[0183] Figures 12A-12B An example of a laptop shape factor test strip reader 1200 is shown. The laptop shape factor test strip reader may include a cover 1210 configured to cover a test strip 1220. The laptop shape factor test strip reader may be integrated into a laptop computer (e.g., a personal computer, Apple® laptop computer, Chromebook®, etc.), and the computer processor within the laptop computer can provide computing power to the laptop shape factor test strip reader. Similarly, a battery within the laptop computer can provide power to the laptop shape factor test strip reader.

[0184] Figures 13A-13C An example of a mobile phone housing shape factor test strip reading device 1300 is shown. The phone housing may be configured to accommodate a cellular phone. In some cases, the phone housing shape factor test strip reading device may be configured to be directly attached (e.g., using adhesive) to the mobile phone. The phone housing shape factor test strip reading device may include a cover 1310 configured to cover a test strip 1320. The test strip is removable from a slot 1340 1330. In some cases, the phone housing shape factor test strip reading device may be wirelessly powered by the mobile phone. In some cases, the phone housing shape factor test strip reading device may wirelessly communicate with the mobile phone (e.g., via Bluetooth®).

[0185] Figures 14A-14CAn example of a ring shape factor test strip reading device 1400 is shown. The ring shape factor test strip reading device may include a cover 1410 configured to cover a test strip 1420. The cover may be removable to expose the test strip. In some cases, the cover is slidable to expose the test strip. In some cases, the test strip may be removed from a slot 1440 1430, and the ring shape factor test strip reading device may be reusable. In some cases, the ring shape factor test strip reading device may include a rechargeable battery.

[0186] Figures 15A-15C An example of a Universal Serial Bus (USB) plug-in shape factor test strip reader 1500 is shown. The USB plug-in shape factor test strip reader can be configured to be inserted into a USB port, such as that of a mobile phone 1540. The USB plug-in shape factor test strip reader can include a cover 1510 configured to cover a test strip 1520, which can be removed from a slot 1540 1530. The USB port can provide data access and power delivery to the USB plug-in shape factor test strip reader.

[0187] Figures 16A-16C An example of a smart watchband shape factor test strip reading device 1600 is shown. A smartwatch 1640 may have the smart watchband shape factor test strip reading device 1600 inserted through the watchband of the smartwatch, thereby reversibly attaching the smart watchband shape factor test strip reading device to the smartwatch. The smart watchband shape factor test strip reading device may include a cover 1610 movable to expose a test strip 1620. The test strip can be removed from the slot 1640 1630. The smart watchband shape factor test strip reading device can be configured to communicate wirelessly with the smartwatch. In some cases, the smart watchband shape factor test strip reading device can be used with a non-smartwatch.

[0188] Figures 17A-17B An example of a handheld shape factor test strip reading device 1700 is shown. The handheld shape factor test strip reading device may include a cover 1710 as described elsewhere herein. The cover may be slidable to expose the test strip. The cover may include a gap 1711 configured to allow a user's finger to contact the cover to move it. The handheld shape factor test strip reading device may include a ridge 1750 configured to guide the user's finger to the cover 1710. The body 1730 of the handheld shape factor test strip reading device may be configured to include, for example, a battery, a battery cover 1760, a microprocessor, a screen 1720, a plurality of buttons 1740, etc., or any combination thereof. The handheld shape factor test strip reading device may be configured to implement the methods of this disclosure (e.g., determining a user's blood glucose level).

[0189] Figures 18A-18BAn example of a pressure switch 1800 and integrated into a test strip reading device 1700 is shown. The test strip reading device may be as described elsewhere herein. The test strip reading device may include the pressure switch 1800, which is configured to provide a reading regarding the presence and / or amount of pressure applied to a test strip held in the test strip reading device. For example, the pressure switch may detect pressure applied to the test strip and, for example, initiate a method of this disclosure to determine the nature of biomarkers in a user's sweat. In another example, the pressure switch may record the amount of pressure applied to the test strip throughout the reading, thereby providing feedback to the user regarding the amount of pressure applied. In this example, if the user provides too much or too little pressure, the test strip reading device may (e.g., via a display) communicate with the user to correct the amount of pressure applied.

[0190] The pressure switch 1800 may include a switching unit 1801. The switching unit may be configured to receive movement from the test strip, for example, when a user places their finger on the test strip. The switching unit may include, for example, one or more electromechanical pressure switches, electronic pressure switches, solid-state pressure switches, capacitive pressure switches, etc., or any combination thereof. In some cases, the switching unit is a tactile switch, an optical switch, or a combination thereof. The switching unit may include a contact 1802 configured to be electrically connected to an electrical lead 1804, which is part of a strip 1803. The strip and the corresponding lead can be connected to the switching unit in a low-cost and easy-to-manufacture manner. The strip may include end leads 1805, which can be used to connect the strip to the rest of the test strip reading device. The test strip reading device 1700 may include a base housing 1830 and a stepped block 1840 configured to protect the strip 1803 and the lead 1804. An optional protective barrier 1820 may be positioned between the test strip and the switching unit to, for example, prevent debris from entering the test strip reading device and protect the switching unit from abrasion. The protective barrier may include, for example, polyethylene terephthalate, polypropylene, polyvinyl chloride, polycarbonate, polyimide, polytetrafluoroethylene, etc., or any combination thereof. The protective barrier may be configured to provide a spring-like action to reset the test strip and switch unit after the user has removed their finger. For example, the protective barrier may be raised in the middle where the switch unit is located. The raised portion may provide a spring force.

[0191] Figures 19A-19C An example of activating a pressure switch in a test strip reading device is shown. Figure 19A A test strip 1911 is shown above the switching unit 1912, where the switching unit is not activated and the test strip has no pressure 1910. Figure 19B During the test, the test strip is under pressure of 1920, and the switch unit is pressed down and activated.

[0192] Figure 19CAn area 1930 surrounding a test strip and a pressure switch, according to some embodiments, is shown. A printed circuit board 1931 may house a processor and other electronic components as described elsewhere herein. A test strip holder 1932 may be positioned above a switching unit 1933 such that the test strip can be movably communicated with the switching unit. A step block 1934 may be positioned as a stop to prevent overtravel of the test strip and to provide structural support for a test strip reading device. A cover 1935 may be configured, as described elsewhere herein (e.g., to protect the test strip).

[0193] Figure 20 An example exploded view of a test strip reading device 2000 is shown. The test strip reading device may include a top cover 2001 and a bottom cover 2004 configured to hold the components of the test strip reading device. A display 2002 may be configured to provide information to a user of the test strip reading device. A printed circuit board 2003 may be configured to hold and interconnect the electronic components of the test strip reading device. Step blocks 2005 and protective barriers 2007 may be as described elsewhere herein. A switch unit 2008 may be configured as described elsewhere herein. A label 2006 may provide, for example, model information, serial number, other listings, patent information, etc., or any combination thereof. Screws 2009 may secure the top and bottom covers and hold the test strip reading device together. Insulating tape 2010 may be configured to provide insulation and may include, for example, Kapton tape. A cover 2011 may be configured to cover the test strip reading area and may be as described elsewhere herein. A battery cover 2012 may be configured to allow battery replacement, as described elsewhere herein.

[0194] Additional numbered embodiments 1. A portable sweat-based analyte monitoring system, the system comprising: a) A test strip comprising a solid-state electrochemical sensor layer and a conductive layer; and b) Test strip reading device. The test strip is configured to contact a portion of the user's skin to receive a sample from the skin, and The test strip reading device is configured to receive the test strip.

[0195] 2. The system according to Example 1, wherein the sample comprises sweat.

[0196] 3. The system according to any one of the foregoing embodiments, wherein the conductive layer comprises a conductive material.

[0197] 4. The system according to any one of the foregoing embodiments, wherein the conductive material comprises one or more of a metal, a doped ceramic, a carbonaceous material, or a conductive polymer.

[0198] 5. The system according to Example 4, wherein the metal includes one or more of gold, silver, copper, ruthenium, rhodium, platinum, bismuth, tungsten, iron, titanium, rhenium, osmium, or iridium.

[0199] 6. The system according to Example 4, wherein the doped ceramic comprises one or more of indium tin oxide, aluminum-doped zinc oxide, or fluorine-doped tin oxide.

[0200] 7. The system according to Example 4, wherein the carbonaceous material includes one or more of graphite, carbon black, carbon nanotubes, graphene, or reduced graphene oxide.

[0201] 8. The system according to Example 4, wherein the conductive polymer comprises one or more of poly(3,4-ethylenedioxythiophene)polystyrene sulfonate, polypyrrole, polyaniline, polyphenylene diamine, polythiophene, or poly(p-phenylene).

[0202] 9. The system according to any one of the foregoing embodiments, wherein the conductive layer is configured to conduct electrochemical signals and establish an electrical connection to the test strip reading device when the test strip is inserted into the test strip reading device.

[0203] 10. The system according to any one of the foregoing embodiments, wherein the sensor includes an electrochemical transducer with biometric recognition functionality.

[0204] 11. The system according to any one of the foregoing embodiments, wherein the sensor comprises one or more of an enzyme, an ion carrier, a binding polypeptide, a polynucleotide, an aptamer, a molecularly imprinted polymer, or a microorganism.

[0205] 12. The system according to Example 11, wherein the enzyme comprises one or more of glucose oxidase, glucose dehydrogenase, alcohol oxidase, alcohol dehydrogenase, lactate oxidase, lactate dehydrogenase, cholesterol oxidase, uricase, urease, ascorbic acid oxidase, horseradish peroxidase, catalase, tyrosinase, creatinine deiminase, amylase, glutamate oxidase, xanthine oxidase, bilirubin oxidase, hydroxybutyrate dehydrogenase, hydroxybutyrate oxidase, D-amino acid oxidase, L-amino acid oxidase, pyruvate oxidase, or acetoacetate dehydrogenase.

[0206] 13. The system according to Example 11, wherein the binding polypeptide comprises an antibody or an antigen-binding fragment.

[0207] 14. The system according to any one of the foregoing embodiments, wherein the sensor further comprises one or more of a cofactor, mediator, stabilizer, surfactant, polymer, plasticizer, crosslinking agent, crosslinking terminator or crosslinking initiator.

[0208] 15. The system according to Example 14, wherein the cofactor comprises one or more of nicotinamide adenine dinucleotide, nicotinamide adenine dinucleotide phosphate, flavin adenine dinucleotide, flavin mononucleotide, thiamine pyrophosphate, biotin, heme, coenzyme A, coenzyme Q, cobalamin, pyridoxal phosphate, tetrahydrofolate, or S-adenosylmethionine.

[0209] 16. The system according to Example 14, wherein the mediator comprises one or more of ferrocene and ferrocene derivatives, ferricyanide, ferrocyanide, Prussian blue, quinones, tetrathionyl fulvalene, organic dyes (methylene blue, Meldora blue), osmium complexes or ruthenium complexes.

[0210] 17. The system according to Example 14, wherein the stabilizer comprises one or more of glycerol, trehalose, chitosan, albumin, polyethylene glycol, calcium chloride, silica, polyol, diethyl dithiocarbamate, or mercaptoundecanoyl alcohol.

[0211] 18. The system according to Example 14, wherein the surfactant includes Pluronic triblock copolymer, fluorinated surfactant, tetramethyldecynyl glycol, triton-X 100, and trion-X 114.

[0212] 19. The system according to Example 14, wherein the polymer comprises one or more of alginate, chitosan, acrylate, methacrylate or sugar.

[0213] 20. The system according to Example 14, wherein the polymer comprises monomers of the polymer.

[0214] 21. The system according to Example 14, wherein the plasticizer comprises one or more of di-2-ethylhexyl phthalate, diisononyl phthalate, dioctyl adipate, diisononyl adipate, triphenyl phosphate, polyethylene glycol, dibutyl sebacate, dioctyl sebacate, tributyl acetylacetonate, or epoxidized soybean oil.

[0215] 22. The system according to Example 14, wherein the crosslinking agent comprises one or more of glutaraldehyde, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide, polyethylene glycol diglycidyl ether, glyoxal, benzophenone, disuccinimide succinate, bis(sulfosuccinimide) succinate, or dithiobis(succinimide propionate).

[0216] 23. The system according to Example 14, wherein the crosslinking initiator comprises one or more of azobisisobutyronitrile, potassium persulfate, ammonium persulfate, tetramethylethylenediamine, benzoyl peroxide, or Irgacure 2959.

[0217] 24. The system according to any one of the foregoing embodiments, wherein the test strip further includes a substrate.

[0218] 25. The system according to any one of the foregoing embodiments, wherein the substrate comprises one or more of plastic, ceramic or natural materials.

[0219] 26. The system according to any one of the foregoing embodiments, wherein the substrate comprises one or more of polyethylene, polypropylene, polyethylene terephthalate, polyester, polyimide, polydimethylsiloxane, alumina, silicon, or paper.

[0220] 27. The system according to any one of the foregoing embodiments, wherein the substrate is mechanically, chemically and / or physically treated to alter its properties.

[0221] 28. The system according to any one of the foregoing embodiments, wherein the characteristic includes one or more of surface roughness, surface cleanliness, hydrophobicity, dielectric constant, or electrostatic charge.

[0222] 29. The system according to any one of the foregoing embodiments, wherein the substrate treatment includes one or more of alkaline chemical etching, plasma etching, electroplating, abrasion, laser ablation, sputtering, heating, and physical or chemical vapor deposition.

[0223] 30. The system according to any one of the foregoing embodiments, wherein the substrate treatment improves the adhesion and / or compatibility of the sample.

[0224] 31. The system according to any one of the foregoing embodiments, wherein the test strip further includes an insulating layer.

[0225] 32. The system according to any one of the foregoing embodiments, wherein the insulating layer comprises a non-conductive material.

[0226] 33. The system according to any one of the foregoing embodiments, wherein the insulating layer is waterproof.

[0227] 34. The system according to any one of the foregoing embodiments, wherein the insulating layer is rigid.

[0228] 35. The system according to any one of the foregoing embodiments, wherein the insulating layer is transparent.

[0229] 36. The system according to any one of the foregoing embodiments, wherein the insulating layer has antibacterial properties.

[0230] 37. The system according to any one of the foregoing embodiments, wherein the insulating layer covers a portion of the test strip to define an exposed area for contact with the skin.

[0231] 38. The system according to any one of the foregoing embodiments, wherein the insulating layer is deposited or attached to another layer of the test strip.

[0232] 39. The system according to any one of the foregoing embodiments, wherein the test strip further includes an anti-interference layer.

[0233] 40. The system according to any one of the foregoing embodiments, wherein the anti-interference layer comprises one or more of a metal, a mediator, a negatively charged or positively charged molecule.

[0234] 41. The system according to Example 40, wherein the mediator comprises one or more of ferrocene and ferrocene derivatives, ferrocyanide, ferricyanide, Prussian blue, quinones, tetrathione, organic dyes, osmium complexes, or ruthenium complexes.

[0235] 42. The system according to Example 41, wherein the organic dye comprises one or more of methylene blue or Meldora blue.

[0236] 43. The system according to Example 40, wherein the negatively or positively charged molecules include one or more of Nafion, polyfluoroalkane, polychlorotrifluoroethylene, fluororubber, chitosan, polyethyleneimine, polyurethane, polystyrene sulfonate, polyvinyl sulfate, polyvinyl alcohol, or polyvinyl chloride.

[0237] 44. The system according to Example 43, wherein the fluororubber comprises one or more copolymers of vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene and perfluoromethyl vinyl ether.

[0238] 45. The system according to Example 43, wherein the fluororubber comprises ethylene and propylene added to the copolymer.

[0239] 46. ​​The system according to any one of the foregoing embodiments, wherein the test strip further includes a protective layer.

[0240] 47. The system according to any one of the foregoing embodiments, wherein the protective layer comprises a polymer.

[0241] 48. The system according to Example 45, wherein the polymer comprises one or more of Nafion, chitosan, methyl or ethyl cellulose, polyvinyl chloride, polyurethane, silicone, polytetrafluoroethylene, polyolefin, polyester, polycarbonate, copolymer, polyvinylidene fluoride, polymethyl methacrylate, polyvinyl alcohol, polyethylene glycol, polyacrylamide, polyacetate, polyvinylpyrrolidone, polyethylene oxide, poly(p-phenylene diamine), or polysulfides.

[0242] 49. The system according to any one of the foregoing embodiments, wherein the protective layer is permeable.

[0243] 50. The system according to any one of the foregoing embodiments, wherein the protective layer is configured to protect the underlying layer from mechanical and / or chemical damage.

[0244] 51. The system according to any one of the foregoing embodiments, wherein the test strip further includes a conditioning layer.

[0245] 52. The system according to any one of the foregoing embodiments, wherein the conditioning layer comprises a polymer and a surfactant.

[0246] 53. The system according to any one of the foregoing embodiments, wherein the conditioning layer is configured to regulate the hydrophilicity and electrostatic charge of the electrode.

[0247] 54. The system according to any one of the foregoing embodiments, wherein the test strip is for single use.

[0248] 55. The system according to any one of the foregoing embodiments, wherein the test strip can be reused at least 10 times.

[0249] 56. The system according to any one of the foregoing embodiments, wherein the layer is patterned to improve sweat contact and signal transduction.

[0250] 57. The system according to embodiment 54, wherein the pattern includes one or more of interdigitated patterns, concentric patterns, and radial interdigitated patterns.

[0251] 58. The system according to embodiment 54 or 55, wherein each segment of the line or arc of the pattern is spaced approximately 1 mm apart from each other. 59. The system according to embodiment 54, 55 or 56, wherein the width of the lines or arcs of the pattern does not exceed about 1 mm.

[0252] 60. The system according to any one of the foregoing embodiments, wherein the analyte comprises one or more of sodium, potassium, calcium, magnesium, chloride, fluoride, glucose, lactate, alcohol (ethanol), ketone (β-hydroxybutyrate, acetoacetate), cortisol, uric acid, urea, ascorbate, creatinine, creatine, amino acids (glycine, leucine, proline, lysine, alanine, glutamine, tyrosine, tryptophan, cysteine, leucine, proline, lysine, alanine, glutamine, tyrosine, tryptophan, cysteine), levodopa, caffeine, cannabinoids, cocaine, opioids, explosives, or nerve agents.

[0253] 61. The system according to any one of the foregoing embodiments, wherein the device includes a housing and a circuit board.

[0254] 62. The system according to any one of the foregoing embodiments, wherein the circuit board includes a microcontroller, a signal generation and processing chip, a data storage chip, and a connector configured to receive the test strip.

[0255] 63. The system according to any one of the foregoing embodiments, wherein the circuit board further includes one or more of a wireless transmission function, an antenna, a display panel, indicator lights, user input buttons, or a power supply.

[0256] 64. The system according to embodiment 61, wherein the user input button comprises an electric button or a mechanical button or a combination thereof.

[0257] 65. The system according to any one of the foregoing embodiments, wherein the circuit board is configured to generate an electrochemical measurement when the test strip is inserted into the device and the sample comes into contact with the test strip.

[0258] 66. The system according to any one of the foregoing embodiments, wherein the electrochemical measurement includes one or more of the following: open-circuit voltage measurement, chronopotentiometric method, chronoamperometric method, chronocoulometric method, cyclic voltammetry, differential pulse voltammetry, square wave voltammetry, linear sweep voltammetry, AC impedance spectroscopy, or DC internal resistance measurement.

[0259] 67. The system according to any one of the foregoing embodiments, wherein the circuit board is configured to generate an electrical signal based on an electrochemical measurement from the sample, and to process the electrical signal to determine the concentration of the analyte.

[0260] 68. The system according to any one of the foregoing embodiments, wherein the circuit board processes the electrical signal into the concentration of the analyte using a pre-programmed algorithm and user-input calibration data.

[0261] 69. The system according to any one of the foregoing embodiments, wherein the pre-programmed algorithm includes two-point or single-point linear regression using the calibration data input by the user.

[0262] 70. The system according to any one of the foregoing embodiments, wherein the calibration data input by the user is obtained from another analyte monitoring device.

[0263] 71. The system according to any one of the foregoing embodiments, wherein the other analyte monitoring device includes a blood glucose monitor or a continuous glucose monitor.

[0264] 72. The system according to any one of the foregoing embodiments, wherein the pre-programmed algorithm is personalized for the user.

[0265] 73. The system according to any one of the foregoing embodiments, wherein the pre-programmed algorithm is individualized for different fingers of the user.

[0266] 74. The system according to any one of the foregoing embodiments, wherein the data storage chip is configured to store one or more of the number of times the test strip was used, the raw signal, the processed data, the measurement time, or the personalized and individualized calibration data.

[0267] 75. The system according to any one of the foregoing embodiments, wherein the circuit board is configured to deliver the stored information to an auxiliary device.

[0268] 76. The system according to any one of the foregoing embodiments, wherein the auxiliary device includes one or more of a computer, a mobile device, or a cloud-based data center.

[0269] 77. The system according to any one of the foregoing embodiments, wherein the auxiliary device performs data analysis and data visualization on the stored information.

[0270] 78. The system according to any one of the foregoing embodiments, wherein the device further includes one or more optical sensors or electrical sensors.

[0271] 79. The system according to any one of the foregoing embodiments, wherein the optical sensor or the electrical sensor is configured to measure one or more physiological and physical signals from the skin.

[0272] 80. The system according to any one of the foregoing embodiments, wherein one or more other physiological and physical signals include one or more of temperature, water level, sweat gland density, sweating rate, transdermal water loss rate, pressure, hydration level, heart rate, or blood oxygen level.

[0273] 81. The system according to any one of the foregoing embodiments, wherein the pre-programmed algorithm uses one or more other physiological and physical signals to correct when calculating the analyte concentration based on the electrical signals.

[0274] 82. The system according to any one of the foregoing embodiments, wherein the device further includes an optical, capacitive, or ultrasonic fingerprint scanner to identify the user and finger touching the test strip.

[0275] 83. The system according to any one of the above embodiments, wherein the housing is configured to protect the circuit board and the test strip when inserted into the device.

[0276] 84. The system according to any one of the above embodiments, wherein the housing includes a movable cover to cover a portion of the test strip inserted into the device when the movable cover is closed, and to expose the portion of the test strip when the movable cover is open.

[0277] 85. The system according to any one of the above embodiments, wherein the cover includes a replaceable wiping material or scraper to remove sample residue after contact with skin.

[0278] 86. The system according to any one of the above embodiments, wherein the housing includes a replaceable wipe for wiping the skin before contacting the test strip.

[0279] 87. The system according to any one of the above embodiments, wherein the housing includes a mechanical guide for contact with the skin.

[0280] 88. A method for non-invasively detecting an analyte from a fingertip, the method comprising: a) Insert the test strip of any of the foregoing embodiments into the device of any of the foregoing embodiments; b) Bring a portion of the user's skin into contact with the test strip; and c) Obtain the analyte reading from the test strip reading device.

[0281] 89. A method for non-invasively monitoring analytes from a fingertip, the method comprising: a) By contacting the skin with the test strip, a sample from the user's skin is received on the test strip of any of the aforementioned embodiments, which is inserted into the device of any of the aforementioned embodiments; b) Using a solid-state electrochemical sensor to generate an electrical signal based on electrochemical measurements of the analyte; c) Measure the concentration of the analyte in the sample based on the electrical signal; d) The device calculates the systemic concentration of the analyte in the user based on the concentration of the analyte in the sample; and e) Provide the whole-body concentration of the analyte on the display of the device.

[0282] 90. A method for preparing a test strip for a sweat-based analyte monitoring system, the method comprising: a) Deposit one or more layers on top of the substrate; and b) Attach the deposited layer to the substrate or the previous layer. The test strip includes the substrate, conductive layer, solid-state electrochemical sensor, and insulating layer.

[0283] 91. The method according to Example 88, wherein the deposition includes one or more of electrodeposition, sputtering, physical and chemical vapor deposition, screen printing, transfer printing, dip coating, spraying, spin coating, doctor blade coating, inkjet printing, drop casting, or micro-dot patterning.

[0284] 92. The method according to embodiment 88 or 89, wherein attaching the layer includes one or more of cold pressing, hot pressing, bonding, curling, or embedding.

[0285] 93. The method according to any one of Examples 88 to 90, wherein the layer is patterned to improve sweat contact and signal transduction.

[0286] 94. The method according to any one of Examples 88 to 91, wherein patterning includes one or more of direct deposition or printing, mask deposition or printing, mask etching, laser ablation, laser cutting, mechanical abrasion or mechanical cutting.

[0287] While preferred embodiments of the present disclosure have been shown and described herein, it will be apparent to those skilled in the art that such embodiments have been provided by way of example only. Many variations, modifications, and substitutions will now occur to those skilled in the art without departing from the present disclosure. It should be understood that various alternatives to the embodiments of the present disclosure described herein may be employed in the practice of the present disclosure. The appended claims are intended to define the scope of the present disclosure and thus cover the methods and structures and their equivalents within the scope of these claims.

Claims

1. A system comprising: a test strip comprising a solid-state electrochemical sensor layer and a conductive layer; and a test strip reading device comprising a slot configured to receive a first portion of the test strip and leave a surface of a second portion of the test strip uncovered, wherein the uncovered surface is accessible to contact a portion of a user’s skin.

2. The system of claim 1, further comprising a computer processor operably coupled to the test strip reading device, the computer processor configured to determine a property of the skin using the test strip reading device.

3. The system of claim 1, wherein, the test strip reading device comprises a physical data port.

4. The system of claim 3, wherein, the physical data port is a universal serial bus (USB) port.

5. The system of claim 4, wherein, the USB port is configured to allow communication between the test strip reading device and a computing system.

6. The system of claim 4, wherein, the USB port is configured to receive power from a computing system when connected to the computing system.

7. The system of claim 1, wherein, the test strip reading device comprises a wireless communication module.

8. The system of claim 7, wherein, the wireless communication module comprises a Bluetooth® communication module, a Wi-Fi® communication module, a near field communication (NFC) module, a cellular communication module, a radio communication module, an ultra-wideband communication module, or any combination thereof.

9. The system of claim 1, wherein, the test strip reading device is reusable.

10. The system of claim 1, wherein, the test strip is reusable.

11. The system of claim 10, wherein, the test strip is reusable for at least about 3 days.

12. The system of claim 11, wherein, the test strip is reusable for at least about 7 days.

13. The system of claim 10, wherein, the test strip is reusable for at least about 15 times.

14. The system of claim 1, wherein, the test strip is not reusable.

15. The system of claim 1, wherein, the test strip reading device is not reusable.

16. The system of claim 1, wherein, the test strip reading device is configured to allow removal of the test strip after testing the skin.

17. The system of claim 16, wherein, the test strip reading device is configured to receive an additional test strip after the removal of the test strip.

18. The system of claim 1, wherein, the test strip reading device is configured to attach to a computing device.

19. The system of claim 18, wherein, the computing device is a mobile phone, a watch, a wearable device, or a laptop computer.

20. The system of claim 1, wherein, the test strip reading device comprises a microprocessor configured to interface with the test strip to obtain a measurement from the test strip.

21. The system of claim 1, further comprising a cover positioned to protect the uncovered surface of the test strip.

22. The system of claim 21, wherein, the cover is slidable relative to the test strip reading device.

23. The system of claim 21, wherein, the cover is attached to the test strip reading device using a hinge.

24. The system of claim 21, wherein, the cover comprises one or more sensors configured to determine an open or closed state of the cover.

25. The system of claim 1, wherein the test strip reading device has a volume of at most about 4 cubic centimeters (cm3). 3 ) of the test strip reading device.

26. The system of claim 1, wherein, the test strip reading device is configured to guide a user’s finger to the test strip.

27. The system of claim 1, further comprising a display in the test strip reading device.

28. The system of claim 1, further comprising one or more physical buttons.

29. The system of claim 1, wherein, the test strip reading device comprises one or more sensors.

30. The system of claim 29, wherein, The one or more sensors are configured to acquire one or more signals including a temperature of the user, a temperature of the test strip reading device, a moisture level of the user, a humidity, a sweat gland density of the user, a sweat rate of the user, a transepidermal water loss rate of the user, a pressure, a skin hydration level of the user, a heart rate of the user, a blood oxygen level of the user, a blood pressure of the user, a skin conductance of the user, a skin capacitance of the user, a skin resistance of the user, a skin impedance of the user, or any combination thereof.

31. The system of claim 1, wherein, The test strip reading device has a credit card form factor, a keychain form factor, or a ring form factor.

32. The system of claim 1, wherein, The test strip reading device is integrated in a laptop computer.

33. The system of claim 1, wherein, The test strip reading device is configured to be integrated into or associated with a mobile phone housing.

34. The system of claim 33, wherein, The test strip reading device is configured to be covered by a portion of the mobile phone housing.

35. A method comprising: (a) providing a test strip reading device holding a test strip, the test strip comprising a solid-state electrochemical sensor layer and a conductive layer; (b) contacting the test strip with a portion of a subject’s skin; (c) using the solid-state electrochemical sensor layer and the conductive layer to generate an electrical measurement based on a biomarker from the portion of the subject’s skin or sweat exuded thereon; and (d) using the electrical measurement to determine a property of the biomarker of the subject.

36. The method of claim 35, wherein, The property of the biomarker is a blood glucose level of the subject.

37. The method of claim 35, further comprising using a calibration measurement in determining the property of the biomarker.

38. The method of claim 35, wherein, The determination of the property of the biomarker is performed without pre-calibration.

39. The method of claim 35, further comprising, prior to (b), opening a cover attached to the test strip reading device to expose the test strip.

40. The method of claim 35, wherein, The test strip is reusable.

41. The method of claim 40, wherein, The test strip is reusable for at least about 15 times.

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