Handheld dropper experimental system for urine health testing

Abstract

The present invention discloses a handheld dropper experimental system for urine health detection. The system adopts laser-induced graphene technology to construct a low-cost electrochemical electrode with a high specific surface area. Nanogold branches and a sensitive layer are constructed on the electrode surface by electrochemical methods, and the porous enzyme membrane is modified, which effectively enhances the degree of immobilization and stability of the enzyme, thereby improving the service life and anti-interference ability of the sensor. In addition, the porous structure of the enzyme membrane promotes the rapid transmission of electrons and efficient enzyme catalytic reactions. The electrode is designed as a disposable dropper structure and is equipped with a pipette-type integrated electrochemical detection system to achieve convenient and instant biochemical detection. The present invention can realize home monitoring and daily health management of chronic diseases by detecting disease markers in urine, providing strong technical support for long-term health monitoring.

Description

Technical Field

[0001] The present invention relates to the technical field of urine marker detection, and in particular to a handheld dropper experimental system for urine health detection, which realizes instant analysis of urine samples and long-term health monitoring. Background Art

[0002] Urine testing, as an important means of chronic disease monitoring, usually requires complex operations and professional equipment, and requires patients to go to the hospital for examination, which is often time-consuming and laborious. In addition, although other methods such as blood testing can be completed at home, this method will cause certain trauma to patients. Therefore, there is an urgent need to develop a simple, fast, low-cost and non-invasive detection method to achieve long-term monitoring and health management of chronic diseases. Summary of the invention

[0003] The purpose of the present invention is to provide a handheld dropper experimental system for urine health testing in view of the deficiencies of the prior art.

[0004] The objective of the present invention is achieved through the following technical scheme: a handheld dropper experimental system for urine health detection, comprising a dropper-type electrode and a handheld instrument.

[0005] A dropper-type electrode, whose surface is modified with a patterned electrode, is formed by electrochemical deposition of nano-gold branches on the electrode surface, and a composite sensitive material and an enzyme membrane are modified on the nano-gold branches; the dropper-type electrode is rolled and pasted into a dropper-type structure and connected to a quick connector at the bottom of a handheld instrument;

[0006] The handheld instrument absorbs and discharges the test liquid through a piston handle; electrochemical detection is realized through a micro electrochemical workstation module integrated inside the handheld instrument, and data analysis is performed by communicating with a host computer to achieve quantitative detection of hydrogen peroxide, glucose and oxalic acid markers in urine.

[0007] Furthermore, the dropper-type electrode is composed of two tape substrates, one of which is a patterned substrate and the other is a blank substrate; after the electrode pattern is constructed, the patterned substrate is cut into a sector shape, and an indicator line is engraved on the side as a reference boundary when pasting, and an unpatterned blank substrate is also cut out, and an indicator line is also engraved on its side as a reference boundary when pasting; the back of the patterned substrate and the front of the blank substrate are pasted together along the indicator line boundary using the stickiness of the substrate itself, and finally the substrate is rolled into a conical structure along the side line, so that the indicator line boundary parts of the two substrates overlap and are pasted.

[0008] Furthermore, electrodes, electrode interfaces, leads and insulating layers are constructed on the patterned substrate. The electrodes include 1 reference electrode, 1 counter electrode and the rest are working electrodes. The leads are used to connect the electrodes to the electrode interfaces, and the electrode interfaces are used to establish electrical connections with the quick connectors; the insulating layer is made by cutting tape and attached to the surface of the patterned substrate, exposing only the sector-shaped electrodes and the rectangular electrode interfaces while sealing other areas.

[0009] Furthermore, the formation of the nano-gold branches is performed by electrochemically scanning the working electrode in the gold branch growth solution, so that gold is reduced and precipitated on the surface of the working electrode. The gold branch growth solution is prepared from 100.25 mg of chloroauric acid and 10 ml of 1M HCl solution.

[0010] Furthermore, the composite sensitive material is prepared by sequentially depositing Prussian blue (PB) and nickel hexacyanoferrate (NiHCF) on the working electrode, wherein PB is an ion-electron transducer and NiHCF is a stabilizing layer.

[0011] Furthermore, the deposition of PB is specifically as follows: an electrolyte containing 10 ml of 0.1M HCl and 74.55 mg KCl is prepared, and 4.055 mg FeCl3 and 8.231 mg K3[Fe(CN)6] are added to the electrolyte; and the working electrode of the dropper electrode is electrochemically scanned in the electrolyte to deposit PB.

[0012] Furthermore, the deposition of NiHCF is specifically as follows: a NIHCF deposition solution containing 1.3575 mg NiCl2, 1.6462 mg K3[Fe(CN)6] and 745.5 mg KCl with a total volume of 10 ml is prepared; and the working electrode of the dropper electrode is subjected to electrochemical scanning in the deposition solution to deposit NiHCF.

[0013] Furthermore, the enzyme membrane is a porous enzyme membrane. The porous enzyme membrane is specifically: 1 mg Al2O3 is added to a mixture containing 1 g agarose, 5 g glycerol and 94 g water to form a porous membrane emulsion; the enzyme is dissolved in a buffer to form an enzyme solution, and then the enzyme solution is mixed with the heated porous membrane emulsion, and the mixed solution is dripped on the working electrode and dried naturally.

[0014] Furthermore, the handheld instrument includes an instrument housing, a pipette, a quick connector, a micro electrochemical workstation module and a power module; the instrument housing includes a housing body, a housing front cover and a housing rear cover; the housing front cover is equipped with the micro electrochemical workstation module; the housing rear cover is equipped with the power module;

[0015] A cavity is designed in the center of the shell body for installing a pipette, and the pipette includes a piston handle, a pipette cylinder and a pipette connector. After the pipette is fixedly connected to the cavity of the shell body, the piston handle of the pipette is just higher than the top of the shell body, and the pipette connector at the bottom of the pipette is just lower than the bottom of the shell body; a wire hole is provided at the bottom of the shell body;

[0016] The quick connector is located at the bottom of the instrument and is a double-layer hollow truncated cone, wherein the inner layer is an airtight layer and the outer layer is a conductive layer; through holes are evenly distributed along the circumference of the outer surface of the bottom of the quick connector, which is connected to the conductive layer, and a conductive copper block is embedded in the through hole. The outer side of the conductive copper block is connected to the surface of the quick connector, and the inner side is connected to a wire. The wire airtight layer is airtightly connected to the dropper electrode;

[0017] The dropper electrode is airtightly connected to the quick connector by quick plugging and unplugging. On the one hand, the dropper electrode is airtightly connected to the pipette through the airtight layer of the connector, and the test liquid is sucked into or discharged from the dropper electrode by moving the piston handle of the pipette. On the other hand, the electrode interface of the dropper electrode just contacts the conductive copper block of the quick connector, and finally realizes electrical connection with the electrochemical workstation module.

[0018] The beneficial effects of the present invention are as follows: the present invention uses an electrochemical method to construct nanogold branches on the electrode surface, which effectively enhances the immobilization degree and stability of the enzyme, thereby improving the service life and anti-interference ability of the sensor. In addition, the electrode is designed as a disposable dropper structure and is equipped with a pipette-type integrated electrochemical detection system, which can realize convenient and instant biochemical detection. The present invention can realize home monitoring and daily health management of chronic diseases by detecting disease markers in urine, providing effective technical support for long-term health monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a system schematic diagram of the present invention.

[0020] Figure 2 It is a schematic diagram of making a dropper electrode of the present invention.

[0021] Figure 3 It is a schematic diagram of the dropper electrode structure of the present invention.

[0022] Figure 4 Schematic diagram of a handheld instrument of the present invention.

[0023] Figure 5 yes Figure 4 A schematic diagram of a side view of the handheld instrument of the present invention.

[0024] Figure 6 yes Figure 4 A schematic diagram of the upward viewing angle of the handheld instrument of the present invention.

[0025] Figure 7 yes Figure 4 A schematic diagram of a quick connector for a handheld instrument of the present invention.

[0026] Figure 8 This is a characterization diagram of the gold branch structure using a scanning electron microscope of the present invention.

[0027] Fig. 9 It is an amperometric response diagram of the NiHCF of the present invention for enhancing the stability of PB.

[0028] Fig.10 It is a standard curve diagram of glucose solution catalyzed by the agarase membrane and porous enzyme membrane electrode of the present invention.

[0029] Fig.11 It is a standard curve diagram of H2O2 catalyzed by the LIG electrode of the present invention.

[0030] Fig.12 It is a standard curve diagram of glucose solution catalyzed by the LIG electrode modified with the porous enzyme membrane of the present invention.

[0031] Fig.13 It is a standard curve diagram of oxalic acid catalyzed by the LIG electrode modified porous enzyme membrane of the present invention.

[0032] Fig.14 It is a standard curve diagram of the catalysis of H2O2 by the portable electrochemical workstation and the desktop electrochemical workstation of the present invention. DETAILED DESCRIPTION

[0033] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] like Figure 1 As shown, the present invention proposes a handheld dropper experimental system for urine health detection, including a dropper electrode 1 and a handheld instrument 2.

[0035] The dropper-type electrode 1 is prepared by laser-induced graphene technology and has the characteristics of low cost and high specific surface area; nano-gold branches are constructed on the electrode surface by electrochemical deposition to enhance the load capacity of the sensitive material in the curved sensing interface and increase the specific surface area; the composite sensitive material and the porous enzyme membrane are further modified on the nano-gold branches; the dropper-type electrode 1 is rolled and pasted into a disposable dropper-type structure and connected to the quick connector 21 at the bottom of the handheld instrument 2, thereby achieving a sealed connection and an electrical connection;

[0036] The handheld instrument 2 absorbs and discharges the test liquid through the piston handle 221; electrochemical detection is realized through the micro electrochemical workstation module 23 integrated inside the handheld instrument 2, and the quantitative detection of hydrogen peroxide, glucose and oxalic acid markers in urine is realized through Bluetooth interaction with the host computer.

[0037] Specifically, the dropper-type electrode 1 is composed of two polyimide (PI) tape substrates of the same size and thickness of 0.2 mm, one of which is a patterned PI substrate 3 and the other is a blank PI substrate 4; after the electrode pattern is constructed, the patterned PI substrate 3 is cut into a fan shape by laser cutting, and an indicator line is engraved on the side as a reference boundary for pasting. Similarly, a blank PI substrate 4 without laser-induced graphene patterning is cut out, and an indicator line is also engraved on its side as a reference boundary for pasting; the back of the patterned PI substrate 3 and the front of the blank PI substrate 4 are pasted together along the indicator line boundary by using the viscosity of the PI substrate itself, and finally, they are rolled into a conical structure along the side line of the PI substrate so that the indicator line boundary portions of the two substrates overlap and are pasted. The production and structural schematic diagram of the dropper-type electrode 1 is shown in FIG. Figure 2 and Figure 3 shown.

[0038] Specifically, the patterned PI substrate 3 is made of laser-induced graphene technology, and the electrode pattern is printed on the PI substrate by a laser engraving machine. Before printing, the PI substrate needs to be thoroughly cleaned. An integrated fiber laser marking machine equipped with a third-generation solid-state fiber laser is used to adjust the filling method and line spacing of the vector graphics, and the laser power is set to 8.5%, the frequency is 13 kHz, and the scanning speed is 420 mm / s to achieve the best conductive performance. Six electrodes with an area of ​​about 9 mm are constructed on the patterned PI substrate 3. 2 The structure comprises a sector-shaped electrode, six rectangular electrode interfaces 14, six leads 15 and an insulating layer 16; the six sector-shaped electrodes include one reference electrode 11, one counter electrode 12, and four working electrodes 13, and the surface of the reference electrode 11 is coated with Ag / AgCl slurry; the shape and arrangement of the electrodes are designed according to the surface stress distribution of the dropper-type electrode to ensure that the stress on the electrodes is minimized so that they can be firmly attached to the surface of the patterned PI substrate 3; the six leads 15 are used to connect the sector-shaped electrodes and the rectangular electrode interfaces 14, and the six rectangular electrode interfaces 14 are used to establish an electrical connection with the quick connector 21; the insulating layer 16 is formed by cutting the PI tape with a laser engraving machine, and is attached to the surface of the patterned PI substrate 3 along the indicator line, exposing only the sector-shaped electrodes and the rectangular electrode interfaces 14 and sealing other areas to prevent the leads 15 from contacting the air or the liquid to be tested.

[0039] Specifically, the formation of nano-gold branches is to immerse the working electrode corresponding to the dropper electrode, the external platinum wire counter electrode and the Ag / AgCl reference electrode into the gold branch growth solution, and apply a -0.2 V potential difference to the working electrode in the gold branch growth solution for 4 minutes by constant potential method, so that gold is reduced and precipitated on the surface of the working electrode. The gold branch growth solution is prepared from 100.25 mg of chloroauric acid and 10 ml of 1M HCl solution.

[0040] Specifically, the composite sensitive material is Prussian blue (PB) and nickel hexacyanoferrate (NiHCF) deposited on the working electrode in sequence. PB is an ion-electron transducer. Compared with traditional Pt, its catalytic activity and selectivity for H2O2 in neutral medium are improved by three orders of magnitude; while NiHCF is a stabilizing layer with a structure similar to PB. Because its atomic arrangement is more orderly and its chemical activity is more stable, it greatly improves the overall stability of the sensor without affecting the catalytic performance of PB.

[0041] Specifically, the PB deposition is as follows: an electrolyte containing 10 ml of 0.1M HCl and 74.55 mg KCl is prepared, and 4.055 mg FeCl3 and 8.231 mg K3[Fe(CN)6] are added to the electrolyte. An electrochemical three-electrode system consisting of a working electrode corresponding to a dropper electrode, an external platinum wire counter electrode, and an Ag / AgCl reference electrode is immersed in the electrolyte, and a square wave with an amplitude of 0.5 V, a frequency of 1 Hz, and a duty cycle of 10% is applied to the three-electrode system for 60 cycles of cyclic deposition.

[0042] Specifically, the NiHCF deposition method includes preparing a NIHCF deposition solution containing 1.3575 mg NiCl2, 1.6462 mg K3[Fe(CN)6] and 745.5 mg KCl in a total volume of 10 ml. The working electrode corresponding to the dropper electrode and the electrochemical three-electrode system consisting of an external platinum wire counter electrode and an Ag / AgCl reference electrode are immersed in the NiHCF deposition solution, and cyclic voltammetry is used to perform 10 cycles of cyclic deposition in the solution. The scanning potential range is set to 0 to 0.8 V, and the scanning rate is 100 mV / s.

[0043] Specifically, the enzyme membrane embeds the target-related oxidase in the membrane solution to provide the enzyme loading and keep it stable. Comparison shows that the porous enzyme membrane has doubled the sensitivity of glucose detection compared to the agarase membrane.

[0044] Specifically, the porous enzyme membrane: 1 mg Al2O3 is added to a mixture containing 1 g agarose, 5 g glycerol and 94 g water to form a porous membrane emulsion; the porous membrane emulsion is heated at 80°C for 6 h, and the membrane emulsion is shaken evenly every 1 h. 1 mg glucose oxidase is dissolved in 100 μL PBS buffer with a pH of 7.2 to form an enzyme solution, and then the enzyme solution and the porous membrane emulsion are mixed in a volume ratio of 1:2, and 4 μL of the mixed solution is dropped on the working electrode and dried naturally.

[0045] Specifically, the agarase membrane: prepare a 1% agarose solution as an agar membrane emulsion. Heat the agar membrane emulsion at 80°C for 6 h, and oscillate the membrane emulsion evenly every 1 h. Dissolve 1 mg of glucose oxidase in 100 μL of PBS buffer with a pH of 7.2 to form an enzyme solution, then mix the enzyme solution with the agar membrane emulsion in a volume ratio of 1:2, take 4 μL of the mixed solution and drop it on the working electrode, and dry it naturally.

[0046] Specifically, the handheld instrument 2 includes an instrument housing 25, a pipette 22, a quick connector 21, a micro electrochemical workstation module 23 and a power module 26. The instrument housing includes a housing body 251, a housing front cover 252 and a housing back cover 253. The housing front cover 252 is installed with a micro electrochemical workstation module 23; the micro electrochemical workstation module 23 includes a power supply voltage stabilization module, a microcontroller STM32 module, a data conversion module, an electrochemical front-end module and a Bluetooth communication module, which can realize common electrochemical treatment methods such as cyclic voltammetry and square wave voltammetry. The housing back cover 253 is installed with a power module 26.

[0047] A cavity is designed in the center of the shell body 251 for installing the pipette 22. The pipette 22 includes a piston handle 221, a pipette cylinder 222 and a pipette connector 223. After the pipette 22 is fixedly connected to the cavity of the shell body 251, the piston handle 221 of the pipette 22 is just higher than the top of the shell body 251, and the pipette connector 223 at the bottom of the pipette 22 is just lower than the bottom of the shell body 251; 6 wire holes 254 are also provided at the bottom of the shell body 251; the quick connector 21 is located at the bottom of the handheld instrument 2, and is a double-layer hollow cone, in which the inner layer is an airtight layer 211 and the outer layer is a conductive layer 212.

[0048] Six rectangular through holes 213 are evenly distributed along the circumference of the outer surface of the bottom of the quick connector 21, which are connected to the conductive layer 212. Conductive copper blocks 214 are embedded in the rectangular through holes 213. The outer side of the conductive copper block 214 is connected to the surface of the quick connector 21, and the inner side is connected to a wire. The wire passes through the six wire holes 254 at the bottom of the shell body 251 and enters the interior of the shell body to connect to the electrochemical workstation module 23; the airtight layer 211 of the inner layer of the quick connector 21 is tightly connected to the pipette connector 223 at the bottom of the pipette 22; there is a circular through hole 215 at the bottom of the quick connector 21, which is used to establish an airtight connection between the airtight layer 211 of the quick connector 21 and the pipette electrode 1. The schematic diagram of the quick connector 21 is shown in FIG. Figure 7 shown.

[0049] The dropper electrode 1 is connected to the quick connector 21 in an airtight manner by quick plugging and unplugging. On the one hand, the dropper electrode 1 is connected to the pipette 22 in an airtight manner by the airtight layer 211 of the quick connector 21, and the test liquid is sucked into or discharged from the dropper electrode 1 by moving the piston handle 221 of the pipette 22. On the other hand, the six rectangular electrode interfaces 14 of the dropper electrode 1 are in contact with the six conductive copper blocks 214 of the quick connector 21, and finally an electrical connection with the electrochemical workstation module 23 is achieved. The schematic diagram of the handheld instrument 2 is shown in FIG. Figures 4 to 7 shown.

[0050] Example 1: The formation of nano-gold branches is to immerse the working electrode corresponding to the dropper electrode, the external platinum wire counter electrode and the Ag / AgCl reference electrode into the gold branch growth solution. The working electrode is applied with a potential difference of -0.2 V and -0.6 V respectively in the gold branch growth solution for 4 minutes by constant potential method, so that gold is reduced and precipitated on the surface of the working electrode. The gold branch growth solution is prepared from 100.25 mg of chloroauric acid and 10 ml of 1M HCl solution. Scanning electron microscopy of the electrode surface is used to obtain the deposited gold branch morphology as shown in the figure. Figure 8 (a) and Figure 8 As shown in (b) in the figure. It can be seen that when the deposition potential is -0.6 V, a gold branch with a "thorn" morphology is formed. This is because the precipitation rate of gold atoms is faster under a larger negative potential, resulting in a larger gradient of the chloroauric acid solution at the tip of the phase, which makes it tend to grow along the "trunk" and ignores the smaller solid phases in its side branches. When the deposition potential is -0.2 V, a gold branch with an "olive branch" morphology is formed. This is because the lower negative potential makes the precipitation rate of the inlet relatively slow, resulting in a slow change in the gradient distribution of the chloroauric acid solution, which not only promotes the growth of the "trunk", but also the tiny protrusions in the side branches will grow and form a more luxuriant structure. Considering the interaction area between the test solution and the enzyme membrane, -0.2 V was selected as the deposition potential.

[0051] Example 2: The composite sensitive material is Prussian blue (PB) and nickel hexacyanoferrate (NiHCF) deposited on the working electrode in sequence. PB is an ion-electron transducer. Compared with traditional Pt, its catalytic activity and selectivity for H2O2 in neutral medium are improved by three orders of magnitude; while NiHCF is a stabilizing layer with a structure similar to PB. Because its atomic arrangement is more orderly and its chemical activity is more stable, it greatly improves the overall stability of the sensor without affecting the catalytic performance of PB.

[0052] Specifically, the PB deposition method comprises the following steps: preparing an electrolyte having a total volume of 10 ml and containing 0.1 ml of 1M HCl and 74.55 mg of KCl, and adding 4.055 mg of FeCl3 and 8.231 mg of K3[Fe(CN)6] to the electrolyte; immersing an electrochemical three-electrode system consisting of a working electrode corresponding to a dropper electrode, an external platinum wire counter electrode, and an Ag / AgCl reference electrode into the electrolyte, and applying a square wave cyclic deposition with an amplitude of 0.5 V, a frequency of 1 Hz, and a duty cycle of 10% to the three-electrode system for 60 cycles.

[0053] Specifically, the NiHCF deposition method includes preparing a NIHCF deposition solution containing 1.3575 mg NiCl2, 1.6462 mg K3[Fe(CN)6] and 745.5 mg KCl in a total volume of 10 ml; immersing the working electrode corresponding to the dropper electrode and the electrochemical three-electrode system consisting of an external platinum wire counter electrode and an Ag / AgCl reference electrode in the NiHCF deposition solution, and performing cyclic deposition in the solution for 10 cycles by cyclic voltammetry. The scanning potential range is set to 0 to 0.8 V, and the scanning rate is 100 mV / s.

[0054] In order to prove that NiHCF can enhance the stability of PB, the current changes of the electrode deposited with PB and the electrode deposited with PB+NiHCF were compared in a 2 mM H2O2 solution by constant potential method for 30 min. Fig. 9 As shown in the figure, it can be seen that the current response of the electrode deposited with only PB shows a significant decrease during the long-term measurement, while the current response of the electrode deposited with PB and NiHCF remains almost unchanged during the measurement. This shows that depositing NiHCF on the surface of PB greatly improves the stability of PB.

[0055] Example 3: The enzyme membrane is to embed the target-related oxidase in the membrane solution to provide the enzyme loading and keep it stable. In order to compare the effect of the enzyme membrane, the it curves of the electrodes with fixed agarase membrane and porous enzyme membrane in a series of glucose solutions with concentration gradients (the concentrations are 20 μM, 50 μM, 100 μM, 200 μM, 500 μM, 700 μM, 1000μM, 3000 μM, 5000 μM) were measured, and the current intensity of the electrode at different concentrations at 100 s was plotted, as shown in Figure 3. Fig.10 shown.

[0056] Specifically, the porous enzyme membrane: 1 mg Al2O3 is added to a mixture containing 1 g agarose, 5 g glycerol and 94 g water to form a porous membrane emulsion; the porous membrane emulsion is heated at 80°C for 6 h, and the membrane emulsion is shaken evenly every 1 h. 1 mg glucose oxidase is dissolved in 100 μL PBS buffer with pH = 7.2 to form an enzyme solution, and then the enzyme solution and the porous membrane emulsion are mixed in a volume ratio of 1:2, and 4 μL of the mixed solution is dropped on the working electrode and dried naturally.

[0057] Specifically, the agarase membrane: prepare a 1% agarose solution as an agar membrane emulsion. Heat the agar membrane emulsion at 80°C for 6 h, and oscillate the membrane emulsion evenly every 1 h. Dissolve 1 mg of glucose oxidase in 100 μL of PBS buffer with a pH of 7.2 to form an enzyme solution, then mix the enzyme solution with the agar membrane emulsion in a volume ratio of 1:2, take 4 μL of the mixed solution and drop it on the working electrode, and dry it naturally.

[0058] from Fig.10 The sensitivity of agarase membrane electrode to glucose catalysis is -0.6 μA·mM -1 , the linearity is 0.9922; the sensitivity of porous enzyme membrane electrode to glucose is -1.2 μA·mM -1 , the linearity is 0.9954. It can be found that the sensitivity of the porous enzyme membrane to glucose detection is doubled compared with the agarase membrane, so the porous enzyme membrane was finally selected.

[0059] Example 4: After verifying and optimizing the above sensing mechanism and sensitive materials, the sensing system was constructed on the LIG electrode. First, a gold branch structure was constructed on the surface of the LIG electrode at a potential of -0.2 V in a chloroauric acid solution, and PB and NiHCF were further deposited on the electrode. CV was scanned in H2O2 solutions with different concentration gradients (concentrations were 0 mM, 5 mM, 10 mM, and 20 mM, respectively). The peak value of the reduction peak was plotted to obtain Fig.11 The test results show that the sensitivity of the constructed LIG electrode to H2O2 is -9.7 μA·mM -1 , the linearity is 0.9994.

[0060] Subsequently, the porous enzyme membranes were further modified on the basis of the PB layer and the NiHCF layer, including porous enzyme membranes encapsulating glucose oxidase and porous enzyme membranes encapsulating oxalate oxidase. The responses to different concentrations of glucose and oxalic acid were tested, and standard curves were established. First, the it curves of the LIG electrode in a series of glucose solutions with a concentration gradient (the concentrations were 20 μM, 50 μM, 100 μM, 200 μM, 500 μM, 700 μM, 1000 μM) were measured, and the current intensity of the electrode at different concentrations at 100 s was plotted, as shown in Figure 2. Fig.12 As shown in Figure 2, the sensitivity of the porous enzyme membrane electrode to catalyze glucose on the LIG electrode is -2.2 μA·mM -1 , the linearity is 0.9809.

[0061] The LIG electrode was immersed in a PBS solution and oxalic acid was added dropwise to change the oxalic acid concentration in the solution. The it curve was tested and the current response of the electrode at different concentrations (20 μM, 40 μM, 60 μM, 80 μM, 100 μM, 200 μM, 400 μM, 600 μM, 800 μM, 1 mM, 2 mM, 4 mM, 6 mM, 8 mM, 10 mM) was plotted, as shown in Figure 2. Fig.13 As shown in the figure, the sensitivity of the porous enzyme membrane electrode to catalyze oxalic acid is -1.7 μA·mM -1 , the linearity is 0.9995.

[0062] Example 5: A micro electrochemical workstation module is installed on the front cover of the housing. The micro electrochemical workstation module includes a power supply voltage regulator module, a microcontroller STM32 module, a data conversion module, an electrochemical front-end module and a Bluetooth communication module, which can realize common electrochemical treatment methods such as cyclic voltammetry and square wave voltammetry. After establishing communication with the PC via the Bluetooth module, the commercial carbon electrode is connected to the portable electrochemical workstation and placed in a potassium ferrocyanide solution. The desktop APP parameters are set to cyclic voltammetry, with a maximum voltage of 0.6 V, a minimum voltage of -0.2 V, a rate of 0.1 V / s, and a forward scan starting from 0 V. Use a portable electrochemical workstation to scan CV for the electrode in H2O2 solutions with different concentration gradients (concentrations are 0 mM, 5 mM, 10 mM, 20 mM, and 30 mM, respectively). According to the peak value of the reduction peak, the peak value is plotted. Fig.14 The test results show that the sensitivity of the LIG electrode to H2O2 measured by the portable electrochemical workstation is -9 μA·mM -1 , and the linearity is 0.9994. The final results are basically consistent with those obtained by the desktop electrochemical workstation, proving that the functions of the portable electrochemical workstation and the desktop APP are as expected.

[0063] It should be stated that the content and specific implementation methods of the present invention are intended to demonstrate the practical application of the technical solution provided by the present invention and should not be interpreted as limiting the scope of protection of the present invention. Any modifications and changes made to the present invention within the spirit of the present invention and the protection scope of the claims shall fall within the protection scope of the present invention.

Claims

1. A handheld dropper experimental system for urine health testing, characterized in that: The system includes a dropper electrode and a handheld instrument; A dropper-type electrode, whose surface is modified with a patterned electrode, nano-gold branches are constructed on the electrode surface by electrochemical deposition, and composite sensitive materials and enzyme membranes are modified on the nano-gold branches; the dropper-type electrode is rolled and pasted into a dropper-type structure and connected to a quick connector at the bottom of a handheld instrument; an electrode, an electrode interface, a lead and an insulating layer are constructed on the substrate of the patterned electrode; the electrode includes a reference electrode, a counter electrode, and the rest are working electrodes; the lead is used to connect the electrode and the electrode interface, and the electrode interface is used to establish an electrical connection with the quick connector; the insulating layer is made by cutting tape and attached to the surface of the patterned substrate, exposing only the fan-shaped electrode and the rectangular electrode interface and sealing other areas; the formation of the nano-gold branches is to perform electrochemical scanning on the working electrode in a gold branch growth solution using an electrochemical method, so that gold is reduced and precipitated on the surface of the working electrode; the gold branch growth solution is prepared from 100.25 mg of chloroauric acid and 10 ml of a 1M HCl solution; The handheld instrument absorbs and discharges the test liquid through the piston handle; the electrochemical detection is realized through the micro electrochemical workstation module integrated in the handheld instrument, and the data analysis is carried out by communicating with the host computer to realize the quantitative detection of hydrogen peroxide, glucose and oxalic acid markers in urine; the handheld instrument includes an instrument housing, a pipette, a quick connector, a micro electrochemical workstation module and a power module; The center of the shell is designed with a cavity for installing the pipette, and the pipette includes a piston handle, a pipette cylinder and a pipette connector. After the pipette is fixedly connected to the cavity of the shell, the piston handle of the pipette is just higher than the top of the shell, and the pipette connector at the bottom of the pipette is just lower than the bottom of the shell; the bottom of the shell is provided with a wire hole; The quick connector is located at the bottom of the instrument and is a double-layer hollow truncated cone, wherein the inner layer is an airtight layer and the outer layer is a conductive layer; through holes are evenly distributed along the circumference on the outer surface of the bottom of the quick connector and are connected to the conductive layer, a conductive copper block is embedded in the through hole, the outer side of the conductive copper block is connected to the surface of the quick connector, and the inner side is connected to a wire, which passes through the wire hole at the bottom of the shell into the interior of the shell and is connected to the electrochemical workstation module; the airtight layer of the inner layer of the quick connector is tightly connected to the pipette connector at the bottom of the pipette; there is a through hole at the bottom of the quick connector for establishing an airtight connection between the airtight layer of the quick connector and the pipette electrode; The dropper-type electrode is airtightly connected to the quick connector by means of quick plug-in and pull-out. On the one hand, the dropper-type electrode is airtightly connected to the pipette through the airtight layer of the quick connector, and the test liquid is sucked into or discharged from the dropper-type electrode by moving the piston handle of the pipette. On the other hand, the electrode interface of the dropper-type electrode is in corresponding contact with the conductive copper block of the quick connector, thereby finally achieving electrical connection with the electrochemical workstation module.

2. A handheld dropper experimental system for urine health testing according to claim 1, characterized in that: The dropper-type electrode is composed of two tape substrates, one of which is a patterned substrate and the other is a blank substrate; after the electrode pattern is constructed, the patterned substrate is cut into a sector shape, and an indicator line is engraved on the side as a reference boundary when pasting, and the unpatterned blank substrate is also cut out, and an indicator line is also engraved on its side as a reference boundary when pasting; the back side of the patterned substrate and the front side of the blank substrate are pasted together along the indicator line boundary, and finally the substrates are rolled into a conical structure along the side line, so that the indicator line boundary parts of the two substrates overlap and are pasted.

3. A handheld dropper experimental system for urine health testing according to claim 1, characterized in that: The composite sensitive material is prepared by sequentially depositing Prussian blue PB and nickel hexacyanoferrate NiHCF on a working electrode; the PB is an ion-electron transducer; and the NiHCF is a stabilizing layer.

4. A handheld dropper experimental system for urine health testing according to claim 3, characterized in that: The specific steps of depositing PB are as follows: preparing an electrolyte with a total volume of 10 ml containing 0.1 ml of 1M HCl and 74.55 mg KCl, and adding 4.055 mg FeCl3 and 8.231 mg K3[Fe(CN)6] to the electrolyte; and electrochemically scanning the working electrode of the dropper electrode in the electrolyte to deposit PB.

5. A handheld dropper experimental system for urine health testing according to claim 3, characterized in that: The deposition of NiHCF is specifically as follows: a NIHCF deposition solution containing 1.3575 mg NiCl2, 1.6462 mg K3[Fe(CN)6] and 745.5 mg KCl with a total volume of 10 ml is prepared; and the working electrode of the dropper electrode is subjected to electrochemical scanning in the deposition solution to deposit NiHCF.

6. A handheld dropper experimental system for urine health testing according to claim 1, characterized in that: The enzyme membrane is a porous enzyme membrane; the porous enzyme membrane is specifically: 1 mg Al2O3 is added to a mixture containing 1 g agarose, 5 g glycerol and 94 g water to form a porous membrane emulsion; The enzyme is dissolved in a buffer solution to form an enzyme solution, and then the enzyme solution is mixed with the heated porous membrane emulsion, and the mixed solution is dropped on the working electrode and dried naturally.

Images