760 results about "Electrochemical biosensor" patented technology

This invention relates to a biosensor and more particularly to an electrochemical biosensor for determining the concentration of an analyte in a carrier. The invention is particularly useful for determining the concentration of glucose in blood and is described herein with reference to that use but it should be understood that the invention is applicable to other analytic determinations.

An automated system for continual transdermal extraction of analytes present in a biological system is provided. The system can be used for detecting and / or measuring the concentration of the analyte using an electrochemical biosensor detection means. The system optionally uses reverse iontophoresis to carry out the continual transdermal extraction of the analytes.

A biosensor in the form of a strip. In one embodiment, the biosensor strip comprises an electrode support, a first electrode, i.e., a working electrode, a second electrode, i.e., a counter electrode, and a third electrode, i.e., a reference electrode. Each of the electrodes is disposed on and supported by the electrode support. Each of the electrodes is spaced apart from the other two electrodes. The biosensor strip can include a covering layer, which defines an enclosed space over the electrodes. This enclosed space includes a zone where an analyte in the sample reacts with reagent(s) deposited at the working electrode. This zone is referred to as the reaction zone. The covering layer has an aperture for receiving a sample for introduction into the reaction zone. The biosensor strip can also include at least one layer of mesh interposed in the enclosed space between the covering layer and the electrodes in the reaction zone. This layer of mesh facilitates transporting of the sample to the electrodes in the reaction zone. In another embodiment, a biosensor strip can be constructed to provide a configuration that will allow the sample to be introduced to the reaction zone by action of capillary force. In this embodiment, the layer of mesh can be omitted. The invention also provides a method for determining the concentration of glucose in a sample of whole blood by using the biosensor of this invention.

An electrochemical biosensor with electrode elements that possess smooth, high-quality edges. These smooth edges define gaps between electrodes, electrode traces and contact pads. Due to the remarkable edge smoothness achieved with the present invention, the gaps can be quite small, which provides marked advantages in terms of test accuracy, speed and the number of different functionalities that can be packed into a single biosensor. Further, the present invention provides a novel biosensor production method in which entire electrode patterns for the inventive biosensors can be formed all at one, in nanoseconds—without regard to the complexity of the electrode patterns or the amount of conductive material that must be ablated to form them.

There is provided the reagent layer composition that can substantially reduce the measurement bias arising from hematocrits. The addition of fatty acid (4-20 carbons) and quaternary ammonium salt to a commonly used reagent layer composition composed of an enzyme, an electron transfer mediator, and several water soluble polymers not only reduce the hematocrit level-dependent bias but also provide very stable performance for an extended period of time. Disclosed are also various types of sub microliter sample volume electrochemical biosensors that are suitable to use with the reagent layer composition of present invention.

An automated system for continual transdermal extraction of analytes present in a biological system is provided. The system can be used for detecting and / or measuring the concentration of the analyte using an electrochemical biosensor detection means. The system optionally uses reverse iontophoresis to carry out the continual transdermal extraction of the analytes.

There is provided the reagent layer composition that can substantially reduce the measurement bias arising from hematocrits. The addition of fatty acid (4-20 carbons) and quaternary ammonium salt to a commonly used reagent layer composition composed of an enzyme, an electron transfer mediator, and several water soluble polymers not only reduce the hematocrit level-dependent bias but also provide very stable performance for an extended period of time. Disclosed are also various types of sub microliter sample volume electrochemical biosensors that are suitable to use with the reagent layer composition of present invention.

There is provided electrochemical biosensors with a sample introducing part, comprising a sample introducing passage, an air discharge passage, and a void. The sample introducing passage communicates with the air discharge passage, and the void is formed at the point of communication. Also, disclosed is the electrochemical biosensor with the said sample introducing part and a fluidity determining electrode.

An electrochemical biosensor formed by screen printing and method of fabricating such biosensor is disclosed in the present invention. The biosensor can quickly absorb a sample to be measured therein, effectively control volume of the sample fed and “fill-and-position” the sample therein. The biosensor includes an electrode layer (electrode area) comprising two or three electrodes, which are a working electrode, a reference electrode and an auxiliary electrode (tri-electrode) on an insulating substrate. An active reaction layer containing reactant, reaction catalyst, mediator, wetting agent and surfactant is spread on the surface of the electrode layer. A sample inflow area is formed above the electrode area by adding an upper cover on top of a middle insulating layer with a U-shaped opening formed therein. Sample solution with a minute amount about 0.8 to 1 μl can be rapidly introduced into the electrode area and the active reaction layer via the inflow area by siphon or capillary, where the ingredient of the sample can be analysed by measuring reaction between the sample, reaction catalyst and mediator in the reaction layer using electrochemical potentiometric or amperometric method. An upwardly extended closed space formed within the upper cover above the electrode area adjacent to the front of conductive wires can be effectively used to control sample volume and “fill-and-position” the sample.

An electrochemical biosensor strip has a base, an electrode system, an optional spacer and a cover. The electrode system is laid on the base. The spacer is laid on the electrode system and exposes a portion of the electrode system for electrical connection with a meter and a different portion of the electrode system for application of a test reagent. The cover is covered on the spacer to form a cavity. Between the test reagent and the base, a hydrophilic layer is laid between them for increasing the binding effect of the test reagent on the base. The hydrophilic layer is laid on the area excluding from the electrode system and laid on the electrode system about 50% to 0% of the electrode system corresponding to the test reagent. The hydrophilic layer will not interfere with signal transmission of the electrode system so the test is more accurate.

A portable multi-functional electrochemical biosensor system includes a plurality of sample cells, pluggable information memories and a multi-functional signal analysis processor. The biosensor system uses a set of sample cell and pluggable information memory to detect the concentration of a corresponding selected analyte. Each sample cell has a reaction zone on which a chemical substance is placed to react with the corresponding analyte and has at least two independent electrodes. During detection, each corresponding pluggable information memory can provide parameters used for analysis. The multi-functional signal analysis processor has a microprocessor, an electrically erasable programmable read / write memory and an environmental temperature sensor. The concentration of the selected analyte is calculated by using the electrochemical reaction signal output from the sample cell and the parameters with cooperation of the environmental temperature sensor, and then an analysis result is output.

The present invention relates to methods and compositions for identifying a pathogen. The inventions provide an antibody-based biosensor probe comprising (AUNT) in combination with a polymer-coated magnetic nanoparticle. In particular, a nanoparticle-based biosensor was developed for detection of Escherichia coli O157:H7 bacterium in food products. Further described are biosensors for detecting pathogens at low concentrations in samples. Even further, a gold nanoparticle-based electrochemical biosensor detection and amplification method for identifying the insertion element gene of Salmonella enterica Serovar Enteritidis is described. The present invention provides compositions and methods for providing a handheld potentiostat system for detecting pathogens outside of the laboratory. The AUNT biosensor system has applications detecting pathogens in food, water, beverages, clinical samples, and environmental samples.

The present invention provides an electrochemical biosensor test strip used for quantitative determination of an analyte in a liquid sample. Methods of fabricating the test strip and reagent formulas are also provided. Improvements in electrochemical test strips are required to detect the presence of a compound in a liquid mixture using a smaller sample size with increased accuracy. The present invention was developed to be user-friendly, decrease sample requirements and decrease analyzing time while increasing the reproducibility and accuracy of the electrochemical test strip.

The invention discloses a high-specific-surface-area boron-doped diamond (BDD) electrode which comprises an electrode substrate. A boron-doped diamond layer is arranged on the surface of the electrode substrate. Or, a transition layer is arranged on the surface of the substrate, and then a boron-doped diamond layer is arranged on the surface of the transition layer. Metal particles are distributed in the diamond layer, and tiny holes and / or pointed cones are distributed on the surface of the diamond layer. Compared with a traditional plate electrode, the boron-doped diamond electrode contains a large number of tiny holes and pointed cones and has the extremely high specific surface area, and the large current intensity is provided through the low current intensity; and meanwhile, due to the different electrode configurations of the substrate and modification of surface graphene and / or carbon nano tubs (CNT), the mass transfer process can be greatly improved, the current efficiency and the electrochemical property are greatly improved, and the BDD electrode with high electrocatalytic activity and high using efficiency is prepared. The electrode can be widely applied in the fields of electrochemical wastewater purification treatment, electrochemical biosensors, strong oxidant electrochemical synthesis, electrochemical detection and the like.

The invention discloses a methods in which dry reagent enzyme based electrochemical biosensors, which are in a relatively mature form due to the extensive amount of development pioneered by the blood glucose monitoring industry, may be simply adapted to perform tests for blood coagulation, enzymatic activity, or immunochemical assays for antigens present in a fluid sample. In particular, the utility of combining apoenzyme based dry reagent electrochemical biosensors with apoenzyme reactivation technology is taught. This combination creates a novel combination dry reagent test technology capable of detecting a wide range of different analytes.

An electrochemical biosensor strip has a base, an electrode system, an optional spacer and a cover. The electrode system is laid on the base. The spacer is laid on the electrode system and exposes a portion of the electrode system for electrical connection with a meter and a different portion of the electrode system for application of a test reagent. The cover is covered on the spacer to form a cavity. Between the test reagent and the base, a hydrophilic layer is laid between them for increasing the binding effect of the test reagent on the base. The hydrophilic layer is laid on the area excluding from the electrode system and laid on the electrode system about 50% to 0% of the electrode system corresponding to the test reagent. The hydrophilic layer will not interfere with signal transmission of the electrode system so the test is more accurate.

A simple, fast, selective and highly sensitive electrochemical method assay and disposable device for detection of viruses, bacteria, proteins, DNA, and / or organic / inorganic compounds. The sensor has a multi-layered construction, with each successive layer performing a different function. The design further allows for the packing of numerous microscopic electrode transducers onto the small footprint of a biochip device, allowing for a high-density array of sensors.

Polymers for use as redox mediators in electrochemical biosensors are described. The transition metal complexes attached to polymeric backbones can be used as redox mediators in enzyme based electrochemical sensors. In such instances, transition metal complexes accept electrons from, or transfer electrons to, enzymes at a high rate and also exchange electrons rapidly with the sensor. The transition metal complexes include at least one substituted or unsubstituted biimidazole ligand and may further include a second substituted or unsubstituted biimidazole ligand or a substituted or unsubstituted bipyridine or pyridylimidazole ligand.

This invention relates to a biosensor and more particularly to an electrochemical biosensor for determining the concentration of an analyte in a carrier. The invention is particularly useful for determining the concentration of glucose in blood and is described herein with reference to that use but it should be understood that the invention is applicable to other analytic determinations.

The invention provides electrochemical biosensors for direct determination of percentage of glycated hemoglobin in blood samples without the need of a separated measurement of total hemoglobin content in blood samples. The invention provides methods for using the electrochemical biosensors.

Disclosed herein is a method for measuring blood glucose levels, using an electrochemical biosensor provided with a converse-type thin-layer electrochemical cell. The electrochemical cell comprising: a working electrode formed on a flat insulating substrate; an auxiliary electrode formed on a separate flat insulating substrate so as to face the working electrode; a fluidity-determining electrode, formed at a predetermined distance from the working electrode on the flat insulating substrate used for the working electrode or the auxiliary electrode; an adhesive spacer, provided with a sample-introducing part having a micro-passage, for spatially separating the working electrode and the auxiliary electrode by being interposed therebetween; an electrode connector, printed with a thick conductive material on a portion of the auxiliary electrode, for three-dimensionally connecting the working electrode to the auxiliary electrode; and a reagent layer containing an electron transfer mediator and an oxidation enzyme.

An electrochemical biosensor formed by screen printing and method of fabricating such biosensor is disclosed in the present invention. The biosensor can quickly absorb a sample to be measured therein, effectively control volume of the sample fed and “fill-and-position” the sample therein. The biosensor includes an electrode layer (electrode area) comprising two or three electrodes, which are a working electrode, a reference electrode and an auxiliary electrode (tri-electrode) on an insulating substrate. An active reaction layer containing reactant, reaction catalyst, mediator, wetting agent and surfactant is spread on the surface of the electrode layer. A sample inflow area is formed above the electrode area by adding an upper cover on top of a middle insulating layer with a U-shaped opening formed therein. Sample solution with a minute amount about 0.8 to 1 μl can be rapidly introduced into the electrode area and the active reaction layer via the inflow area by siphon or capillary, where the ingredient of the sample can be analysed by measuring reaction between the sample, reaction catalyst and mediator in the reaction layer using electrochemical potentiometric or amperometric method. An upwardly extended closed space formed within the upper cover above the electrode area adjacent to the front of conductive wires can be effectively used to control sample volume and “fill-and-position” the sample.

The invention discloses a three-dimensional nitrogen-doped graphene composite material as well as a preparation method and an application thereof to electrochemical biosensors. By means of the characteristics such as high specific surface area, good biocompatibility and high conductivity of the three-dimensional nitrogen-doped graphene, the three-dimensional nitrogen-doped graphene composite material is constructed; the preparation method comprises the following steps: obtaining substrate-containing three-dimensional nitrogen-doped graphene by taking a foam material as a substrate and utilizing a chemical vapor deposition (CVD) method in the presence of inert gas, hydrogen, a carbon source and a nitrogen source, and obtaining the three-dimensional nitrogen-doped graphene composite material by etching and cleaning the three-dimensional nitrogen-doped graphene. By compounding the three-dimensional nitrogen-doped graphene with enzyme / non-enzyme materials, corresponding three-dimensional nitrogen-doped graphene composite materials can be obtained; the three-dimensional nitrogen-doped graphene composite materials are prepared into electrodes and have the characteristics of being high in current corresponding sensitivity, good in stability and wide in application range when being used for detecting a plurality of molecules such as glucose, dopamine, paracetamol and the like.

Networks of single-walled carbon nanotubes (SWCNTs) decorated with Au-coated Pd (Au / Pd) nanocubes are employed as electrochemical biosensors that exhibit excellent sensitivity (2.6 mA mM−1 cm−2) and a low estimated detection limit (2.3 nM) at a signal-to-noise ratio of 3 (S / N=3) in the amperometric sensing of hydrogen peroxide. Biofunctionalization of the Au / Pd nanocube-SWCNT biosensor is demonstrated with the selective immobilization of fluorescently labeled streptavidin on the nanocube surfaces via thiol linking. Similarly, glucose oxidase (GOx) is linked to the surface of the nanocubes for amperometric glucose sensing. The exhibited glucose detection limit of 1.3_M (S / N=3) and linear range spanning from 10 μM to 50 mM substantially surpass other CNT-based biosensors. These results, combined with the structure's compatibility with a wide range of biofunctionalization procedures, would make the nanocube-SWCNT biosensor exceptionally useful for glucose detection in diabetic patients and well suited for a wide range of amperometric detection schemes for biomarkers.

An electrochemical biosensor strip has a base, an electrode system, a spacer and a cover. The electrode system is laid on the base and preferably comprises at least three electrodes. There is a short circuit formed between two selected electrodes of the at least three electrodes. The spacer is laid on the electrode system and exposes a portion of the electrode system for electrical connection with a meter and a different portion of the electrode system for application of a test reagent to those exposed surfaces of electrode system. The test reagent is a reagent that is specific for the test to be performed by the strip. The cover is covered on the spacer. The short circuit is used to switch on a meter for increasing the operative convenience and further used to recognize the suitable meter. The electrochemical biosensor strip may have a rough unit formed on the base for increasing the adhesion of the test reagent for the test to be performed by the strip.

The invention relates to a modified electrode for a bio-functional multilayer film and a preparation method thereof, which belongs to the technical field of an electrochemical biosensor and preparation thereof. The modified electrode for the bio-functional multilayer film is formed by assembling the bio-functional multilayer film on the surface of a base electrode, the composition of the bio-functional multilayer film can be described as (inorganic nano-plate / biological active substance / high polymer / biological active substance)n, and the base electrode is a platinum electrode or a glass-carbon electrode. The modified electrode for the bio-functional multilayer film combines the biocompatibility of the high polymer and the rigid structure of the inorganic nano-plate, and has the advantages of sensitive signal response, high-efficiency catalytic ability, good operation stability and storage stability.

A biosensor in which at least one reagent constitutes a portion of a working electrode, a conductive track leading from a working electrode to an electrical contact associated with a working electrode, or an electrical contact associated with a working electrode. For example, the biosensor can have a mediator or an enzyme or both incorporated into the working electrode itself. Other reagents can be dispensed on the electrode itself either directly or by impregnating a matrix, such as a mesh or a membrane, with the enzyme, and then placing the impregnated mesh or membrane over the electrode. Alternatively, the biosensor can have a mediator or an enzyme or both incorporated into the conductive track leading from the working electrode to an electrical contact associated with the working electrode. In another alternative, the biosensor can have a mediator or an enzyme or both incorporated into the electrical contact associated with the working electrode itself. Furthermore, the biosensor can have a mediator or an enzyme or both incorporated into at least two of the foregoing components of the biosensor.

The invention relates to an electrochemical biosensor modified by graphene quantum dots and a preparation method thereof. The electrochemical biosensor is a three-electrode system sensor; in a three-electrode, the counter electrode is a platinum electrode, a reference electrode is a saturated calomel electrode, and a working electrode is a glassy carbon electrode the surface of which is coated with 1-4 layers of the graphene quantum dots. The electrochemical biosensor modified by the graphene quantum dots can successfully recognize an objective single-stranded DNA with the lowest concentration of 50nm; in case of the objective single-stranded DNA, equivalent and complementary single-stranded DNA and the objective single-stranded DNA form a double-stranded DNA; an electrochemical signal and the complementary single-stranded DNA have obvious differences so as to make effects on rapidly detecting the objective single-stranded DNA; and the single-stranded DNA section does not need to be modified by sulfydryl or a fluorescence group, thus achieving convenient application. In the invention, the detected single-stranded DNA is nucleic acid of an arbitrary sequence section; and theoretically the invention is applicable to an arbitrary single-stranded nucleic acid sequence which can not form an internal double-strand, thus the single-stranded nucleic acid sequence is displaced into a specific sequential gene related to diseases, i.e. the invention can be used in gene detection related to diseases, thus having wide application prospect.