Method and sensor for testing analyte concentration in biological sample

Abstract

The invention discloses a method and a sensor for testing the concentration of an analyte in a biological sample, and belongs to the technical field of instant detection of the concentration of the analyte in the biological sample. According to the method, an excitation signal is input into a working electrode, after the excitation signal is completed, the working electrode is in an open circuit state, and a counter electrode attenuation signal is collected; collecting the output current of the excitation signal at regular intervals to obtain an output current group; and the output voltage of the voltage acquisition point of the attenuation signal of the counter electrode is acquired at regular intervals to obtain an output voltage group, and the concentration of the analyte is calculated according to the parameters. According to the method, the mutual influence among various interference factors related to the analyte concentration is eliminated or weakened, and the accuracy, precision and ageing resistance of analyte concentration detection can be improved.

Description

Technical Field

[0001] The present application relates to a method and a sensor for testing the concentration of an analyte in a biological sample, belonging to the technical field of real-time detection of the concentration of an analyte in a biological sample. Background Art

[0002] Traditional bioelectrochemical enzyme sensors achieve test selectivity by catalyzing a single reaction through biomolecules. This is achieved through a two-chain reaction. In the second reaction (the comb flow reaction), the reduced state of the electron mediator diffuses to the electrode and is then oxidized, generating a corresponding current signal. The catalytic process for the analyte can be described by the following three steps:

[0003] (1) Analyte + enzyme oxidation state → → biochemical reaction product + enzyme reduction state;

[0004] (2) Electron mediator oxidized state + enzyme reduced state → → electron mediator reduced state + enzyme oxidized state;

[0005] (3) Electron mediator reduced state (working electrode) → → electron mediator oxidized state +e-.

[0006] For example, the enzyme biomolecules in the glucose or uric acid detection sensor system catalyze the oxidation of glucose or uric acid molecules in the blood, while the added electron mediator reacts with the enzyme, converting the enzyme from a reduced state back to an oxidized state, thereby playing a combing role.

[0007] Glucose enzyme can be an oxidase or a dehydrogenase, and uricase can be an oxidase. Since oxidase will be oxidized by dissolved oxygen in the blood sample, while dehydrogenase will not, there is no "dissolved oxygen effect". The catalytic enzymes of other analytes may be oxidases or dehydrogenases, and their biosensor principles are basically the same. However, during the test, although the enzyme-catalyzed reaction is basically single, there may be other interfering substances that can be oxidized in the blood sample. These interfering substances may undergo oxidation reactions, resulting in interference signals. Generally speaking, the higher the standard potential of the electron mediator of the comb flow reaction, such as potassium ferrocyanide (Fe(CN)6 -3 ), it is easier to generate interference signals, because higher electrode oxidation potential will oxidize more interference substances.

[0008] In addition to the chemical interferents mentioned above, electrochemical biosensors also experience other test interferences. For example, the hematocrit percentage (%-HCT) is a significant interfering factor. This interference occurs when the electron mediator after the comb flow reaction diffuses to the electrode, where its diffusion is hindered by blood cells, causing the diffusion coefficient to vary with the %-HCT. The current in the electrochemical reaction is affected by varying %-HCT values, so factory batch calibration of sensor strips is typically centered around 42% HCT. If the user's %HCT is above 42%, the test current or reading will exhibit a negative deviation; if the user's %HCT is below 42%, the test current or reading will exhibit a positive deviation. Furthermore, the aging effects of the test strips during storage can also interfere with blood glucose test results. Specifically, with extended storage, the sensor's sensitivity decreases and more oxidizable substances are generated, contributing to the background signal. Interfering factors also include the test environment temperature.

[0009] Traditional electrochemical biosensors generally apply voltage to electrodes in contact with the analyte sample, oxidizing the reduced electron mediators produced by the comb flow reaction, thereby generating a current signal responsive to the analyte. This current signal is then converted into the analyte concentration using a corresponding calculation method. For interference factors during the test process, existing methods generally use different single parameters to compensate for or eliminate interference, thereby improving test accuracy and precision. However, these single-parameter interference compensation methods often overlook the interplay between multiple interfering factors, such as the interaction between temperature and HCT, the interaction between temperature and test strip aging, the interaction between HCT and test strip aging, and the interaction between temperature, current, and HCT.

[0010] Therefore, in order to avoid the generation of interference signals, there is still much room for improvement in the analyte concentration testing method in biological samples in terms of multi-pulse excitation, attenuation signal and multi-parameter compensation, so as to further improve the detection accuracy, precision and anti-aging performance of blood glucose concentration and other analyte concentrations in biological samples. Summary of the Invention

[0011] To address the above-mentioned problems, a method and sensor for testing the concentration of an analyte in a biological sample are provided. This method inputs an excitation signal to a working electrode, and obtains the concentration of the target analyte by fitting and calculating the input and output signals. This eliminates or weakens the mutual influence of various interfering factors related to the analyte concentration, thereby improving the accuracy, precision, and anti-aging performance of analyte concentration detection.

[0012] According to one aspect of the present application, a method for testing the concentration of an analyte in a biological sample is provided, which is applied to a biological sample analyte testing device, wherein the biological sample analyte testing device includes an HCT detection electrode, a working electrode, and a counter electrode, wherein the HCT electrode is free of any chemical reagent layer; the working electrode is covered with a chemical reagent that can chemically react with the analyte, an excitation signal is input to the working electrode, and after the excitation signal is completed, the working electrode is in an open circuit state, and an attenuation signal of the counter electrode is collected;

[0013] The output current of the excitation signal is collected at regular intervals to obtain an output current group; the output voltage of the voltage collection point of the electrode attenuation signal is collected at regular intervals to obtain an output voltage group, and the analyte concentration G1 is calculated according to the following formula:

[0014]

[0015]

[0016]

[0017] Among them, i 平均 is the average value of the output current of at least two current collection points in the excitation signal, nA; S is i 平均 The slope of the linear equation with analyte concentration; i n and i j All are output currents in the output current group, nA; i 差 is the difference between the maximum output current of the excitation signal and the output current of the last acquisition point, nA; v o is the output voltage in the output voltage group, V; V is the excitation voltage of the excitation signal, V; the value range of N is 1-50; the value range of J is 1-50; X n The value range of X is 0-140; j The value range is -2-2; X o The value range of is -2-0; the value range of K is 5-20, and the value range of O is 1-30.

[0018] Optionally, the method further includes applying a first AC voltage to the HCT detection electrode before inputting the excitation signal to the working electrode to measure a first impedance value of the biological sample, and obtaining the analyte concentration G1 based on the output current group, the output voltage group, and the first impedance value, wherein:

[0019]

[0020] Wherein, R1 is the first impedance value, Ω; i m is the output current in the output current group, nA; M ranges from 1 to 50; Xm The value range is 0-100;

[0021] Preferably, the method further includes the step of obtaining the measured ambient temperature, and obtaining the analyte concentration G1 according to the output current group, the output voltage group, the first impedance value and the temperature, wherein:

[0022]

[0023] Where T is the ambient temperature, °C; i u is the output current in the output current group, nA; U range is 1-50; X u The value range is -1-1.

[0024] The above calculation formula takes into account the effects of impedance and temperature on analyte concentration, further improving the accuracy and precision of the detection results.

[0025] Optionally, between applying the first AC voltage to the HCT detection electrode and inputting the excitation signal to the working electrode, the method further includes applying a second AC voltage to the HCT detection electrode, wherein the frequencies of the first AC voltage and the second AC voltage are different, so as to measure a second impedance value of the biological sample, and obtaining the analyte concentration G1 based on the output current group, the output voltage group, the first impedance value, and the second impedance value, wherein:

[0026]

[0027] Wherein, R2 is the second impedance value, Ω.

[0028] Preferably, the method further includes the step of obtaining the measured ambient temperature, and obtaining the analyte concentration G1 according to the output current group, the output voltage group, the first impedance value, the second impedance value and the temperature, wherein:

[0029]

[0030] Where T is the ambient temperature, °C; i u is the output current in the output current group, nA; U range is 1-50; X u The value range is -1-1.

[0031] In the above calculation method, i n 、i j 、i m 、i uAll are output currents in the output current group. In the calculation, the above four currents can be the same, different, or partially the same. They are preferably different. The reason is that selecting different current values ​​increases the number of parameter items in the calculation formula, which can reduce the large fluctuation interference on the overall result caused by the fluctuation of individual parameter items, and improve the accuracy and repeatability of the results.

[0032] The frequencies of the applied first AC voltage and the second AC voltage are different, and the ratio of the obtained first impedance value to the second impedance value can offset the influence of the test paper, thereby further improving the accuracy and precision of the detection method.

[0033] Optionally, the frequency of the first applied AC voltage is 1 kHz-100 kHz, and the frequency of the second applied AC voltage is 1 kHz-100 kHz.

[0034] Optionally, the first AC voltage and the second AC voltage are applied discontinuously.

[0035] The discontinuous application can cause the interfering substance to be oxidized under the application of the first AC voltage, thereby reducing the influence of the interfering substance on the test current after the second AC voltage is applied.

[0036] Preferably, the frequency of the first applied AC voltage is 1 kHz, and the frequency of the second applied AC voltage is 10 kHz.

[0037] Optionally, the excitation time of the excitation signal is 3-6s;

[0038] Preferably, the excitation time of the excitation signal is 5s.

[0039] Optionally, i 平均 is the average value of the output current of the last three current acquisition points in the excitation signal.

[0040] Optionally, the voltage value of the excitation signal is 0.1-0.4V;

[0041] Preferably, the voltage value of the excitation signal is 0.3V.

[0042] Optionally, the output current of the current collection point of the excitation signal is collected every 0.1 s.

[0043] Optionally, the output attenuation voltage of the voltage collection point of the electrode attenuation signal is collected every 0.005 s.

[0044] Optionally, the voltage range of the electrode attenuation signal is 0-0.3V, and the attenuation signal is 1-30 continuous output signals;

[0045] Preferably, the attenuation signal is 20-30 continuous output signals.

[0046] According to another aspect of the present application, a sensor for testing the concentration of an analyte in a biological sample is provided, wherein the sensor is capable of executing any one of the above methods for testing the concentration of an analyte in a biological sample.

[0047] The beneficial effects of this application include but are not limited to:

[0048] 1. The method of testing the concentration of an analyte in a biological sample of the present application can solve the technical problem that the interference compensation method of a single parameter in the prior art often ignores the mutual influence relationship between multiple interference factors, resulting in low accuracy and precision of the analyte concentration test.

[0049] 2. The method of testing the analyte concentration in a biological sample of the present application, in addition to the traditional oxidation current signal, introduces a new attenuation electrical signal and a dual-frequency impedance test signal, eliminating or weakening the mutual influence between various interference factors related to the analyte concentration, further improving the accuracy and precision of the analyte concentration in the biological sample.

[0050] 3. The method for testing the analyte concentration in a biological sample of the present application takes into account the mutual influence relationship between various interference factors related to the analyte concentration, eliminates or weakens the influence of the above-mentioned interference factors, and makes it possible to realize the test paper without code adjustment before leaving the factory. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0052] Figure 1 An exemplary embodiment of the main excitation signal schematic diagram of the present application is shown;

[0053] Figure 2 This application shows 平均 An exemplary embodiment of a linear relationship graph with glucose concentration;

[0054] Figure 3 A comparison diagram of the deviations before and after calibration of Example 1 is shown;

[0055] Figure 4 A comparison diagram of the deviation before and after calibration of Example 2 is shown;

[0056] Figure 5 A comparison diagram of the deviation before and after calibration of Example 3 is shown;

[0057] Figure 6 A comparison diagram of the deviation before and after calibration of Example 4 is shown;

[0058] Figure 7 A comparison diagram of the deviation before and after calibration of Example 5 is shown;

[0059] Figure 8 A comparison diagram of the deviation after calibration of Examples 1-5 is shown;

[0060] Figure 9 A comparison diagram of the deviation after calibration of Example 6 is shown. DETAILED DESCRIPTION

[0061] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0062] Unless otherwise specified, the methods used in the embodiments of the present application are conventional methods in the prior art.

[0063] The excitation described in the disclosure of this application is intended to apply an input signal to an electrode in a biological testing device (e.g., a sensor), wherein the applied signal includes a positive or negative DC constant voltage or a positive or negative DC constant current source, etc., so as to cause a complete or partial oxidation or reduction reaction to occur on the electrode surface. The biological testing device system applies an excitation input signal to the corresponding electrode through the connection port between the instrument and the test strip. When the predetermined excitation time ends, the system will no longer apply a signal to the electrode, and the electrode will be in an open circuit state. The open circuit state is not zero input. For example, inputting a voltage of 0V (zero volts) to the working electrode is not equivalent to an open circuit. Zero voltage is also a type of input voltage. When the electrode is in the open circuit state, the oxidation-reduction state substances on the electrode surface and nearby will cause the residual signal to decay. This decay signal will provide a reflection of the state that the electrode has previously experienced, thereby recording other information related to the biological testing device and the analyte concentration.

[0064] Example 1

[0065] This embodiment relates to a method for testing blood glucose concentration in a biological sample, which is applied to a biological sample analyte testing device. The biological sample analyte testing device includes a HCT detection electrode, a working electrode, and a counter electrode. The HCT electrode is free of any chemical reagent layer. The working electrode is coated with a chemical reagent that can chemically react with the analyte. An excitation signal is input to the working electrode. After the excitation signal is completed, the working electrode is in an open circuit state, and an attenuation signal of the counter electrode is collected.

[0066] The output current of the excitation signal is collected at regular intervals to obtain an output current group; the output voltage of the voltage collection point of the electrode attenuation signal is collected at regular intervals to obtain an output voltage group, and the analyte concentration G1 is calculated according to Formula 1:

[0067] G in Formula 1 计算It is obtained by formula 2, and f in formula 1 is obtained by formula 3, where f is the multi-parameter calibration factor.

[0068] Among them, i 平均 is the average value of the output current of at least two current collection points in the excitation signal, nA; S is i 平均 The slope of the linear equation with analyte concentration. Where S is determined by the known history i 平均 and the historical analyte concentrations; or, the historical i of multiple batches of products 平均 After obtaining the linear relationship between the historical analyte concentrations and the historical analyte concentrations through statistical laws, they are directly tabulated and the slope S value is obtained by looking up the table.

[0069] Among them, i n and i j All are output currents in the output current group, nA; i 差 is the difference between the maximum output current of the excitation signal and the output current of the last acquisition point, nA; v o is the output voltage in the output voltage group, V; V is the excitation voltage of the excitation signal, V; the value range of N is 1-50; the value range of J is 1-50; X n The value range of X is 0-140; j The value range is -2-2; X o The value range of is -2-0; the value range of K is 5-20, and the value range of O is 1-30.

[0070] Optionally, i n and i j It can be the output current of the continuous sampling points in the output current group. For example, i n It can be i1, i2, i3, i4, i5, i6, i7, i8, i9, i 10 ;i j It can be i6, i7, i8, i9, i 10 、i 11 、i 12 、i 13 、i 14 、i 15 .

[0071] Optionally, i n and i j It can be the output current of non-continuous sampling points in the output current group. For example, i n It can be i3, i5, i 11 、i 13 、i 21 ;ij It can be i1, i2, i9, i 17 、i 20 、i 29 、i 30 .

[0072] Optionally, v o It can be the output voltage of the continuous sampling points in the output voltage group. For example, v o Can be v1, v2, v3, v4, v5, v6, v7, v8, v9, v 10…… v 30 .

[0073] Optionally, v o The output current of the non-continuous sampling points in the output voltage group can be obtained. For example, v o Can be v1, v3, v6, v 11…… v 20 .

[0074] However, the present invention is not limited thereto, and those skilled in the art can select i according to the significance test method in mathematical statistics. n 、i j and v o value.

[0075] Optionally, the excitation time of the excitation signal is 3-6 s; preferably, the excitation time of the excitation signal is 5 s.

[0076] Optionally, i 平均 is the average value of the output current of the last three current acquisition points in the excitation signal.

[0077] Optionally, the voltage value of the excitation signal is 0.1-0.4V; preferably, the voltage value of the excitation signal is 0.3V.

[0078] Optionally, the output current of the current collection point of the excitation signal is collected every 0.1 s.

[0079] Optionally, the output attenuation voltage of the voltage collection point of the electrode attenuation signal is collected every 0.005 s.

[0080] Optionally, the voltage range of the electrode attenuation signal is 0-0.3V, and the attenuation signal is 1-30 continuous output signals; preferably, the attenuation signal is 20-30 continuous output signals.

[0081] Example 2

[0082] This embodiment, based on the first embodiment, further includes the step of applying a first AC voltage to the HCT detection electrode before inputting the excitation signal to the working electrode to measure a first impedance value of the biological sample, and obtaining an analyte concentration G1 based on the output current group, the output voltage group, and the first impedance value, wherein:

[0083]

[0084] Wherein, R1 is the first impedance value, Ω; i m is the output current in the output current group, nA; M ranges from 1 to 50; X m The value range is 0-100.

[0085] The frequency of the first applied AC voltage is 1 kHz-100 kHz; preferably, the frequency of the first applied AC voltage is 1 kHz.

[0086] Example 3

[0087] This embodiment, based on embodiment 2, further includes the step of obtaining the measured ambient temperature, and obtaining the analyte concentration G1 according to the output current group, the output voltage group, the first impedance value, and the temperature, wherein:

[0088]

[0089] Where T is the ambient temperature, °C; i u is the output current in the output current group, nA; U range is 1-50; X u The value range is -1-1.

[0090] Example 4

[0091] Based on Example 2, this embodiment further includes the step of applying a second AC voltage to the HCT detection electrode between applying the first AC voltage to the HCT detection electrode and inputting the excitation signal to the working electrode. The first AC voltage and the second AC voltage have different frequencies to measure a second impedance value of the biological sample. The analyte concentration G1 is obtained based on the output current group, the output voltage group, the first impedance value, and the second impedance value.

[0092]

[0093] Wherein, R2 is the second impedance value, Ω.

[0094] Optionally, the frequency of the applied second AC voltage is 1 kHz-100 kHz, and the first AC voltage and the second AC voltage are applied discontinuously. Preferably, the frequency of the applied second AC voltage is 10 kHz.

[0095] Example 5

[0096] This embodiment, based on embodiment 4, further includes the step of obtaining the measured ambient temperature, and obtaining the analyte concentration G1 according to the output current group, the output voltage group, the first impedance value, the second impedance value, and the temperature, wherein:

[0097]

[0098] Where T is the ambient temperature, °C; i u is the output current in the output current group, nA; U range is 1-50; X u The value range is -1-1.

[0099] Comparative Example 1

[0100] In this comparative example, the test temperature T, the blood glucose test current value and the impedance value R are obtained, and the temperature compensation impedance value and the temperature compensation current value of the blood glucose are obtained by processing. The temperature compensation impedance value is fitted according to the HCT fitting equation to obtain the HCT value, and then the HCT value is converted into i according to the HCT compensation equation. 初始 , and then combine the current temperature compensation equation (to obtain i) and the current-reading equation to obtain the final blood glucose reading.

[0101] Experimental example

[0102] A sensor capable of executing the above-mentioned embodiment and comparative example analyte concentration calculation method is used to detect a blood sample to be tested. A calculation module is provided in the sensor, and the calculation module includes a calculation formula. The method and process of storing the calculation module are prior art and can be implemented by those skilled in the art, and will not be described in detail in this embodiment.

[0103] The test time and potential control in this test method are:

[0104] (1) A pre-test idle period of 1.5 seconds; during the test idle period, a first AC voltage and a second AC voltage can be applied to the HCT detection electrode to measure the first impedance value and the second impedance value of the blood, respectively. The frequency of the first AC voltage is 1 kHz, the application time is 0.4 seconds, and the interval is 0.7 seconds. The second AC voltage is applied, and the frequency of the second AC voltage is 10 kHz, and the application time is 0.4 seconds.

[0105] (2) Apply an excitation signal to the working electrode, input a 0.3 V potential difference between the working electrode and the counter electrode for 5 seconds, and synchronously measure the output current at intervals of 0.1 seconds;

[0106] (3) After the excitation signal ends, the working electrode is set to an open circuit state, and the potential decay signal of the counter electrode is measured at intervals of 0.005 seconds for 0.15 seconds.

[0107] The total time for the above test steps is 1.5 + 5.0 + 0.15 = 6.65 seconds. Figure 1 As shown, Figure 1 Shows the main excitation signal schematic diagram, Figure 1 The horizontal axis represents the sensor test time, and the vertical axis represents the excitation signal intensity, which is the voltage applied to the electrode.

[0108] refer to Figure 2 As shown, Figure 2 Shows the history of 平均 The linear relationship with the historical analyte concentration is shown in the graph with a slope S of 29.74. 平均 is the average value of the output current of the last three current acquisition points in the excitation signal.

[0109] In Example 1, f = -25.5 + 24.3i9 / i 平均 -0.000054i 差 *i1 / i 平均 +0.000103i 差 *i4 / i 平均 -0.000136i 差 *i6 / i 平均 +0.000200i 差 *i 10 / i 平均 +3.84v3 / V+11.12v4 / V-14.48v5 / V;

[0110] In Example 2, f = -2.484 - 0.405i1 / i 平均 -0.850i2 / i 平均 +3.034i4 / i 平均 -0.001034i 差 *i7 / i 平均 +0.001137i 差 *i8 / i 平均 +17.36v4 / v-16.23v5 / V-0.000044R1*i 10 / i 平均 ;

[0111] In Example 3, f=25.30-11.89i7 / i 平均 -13.40i 10 / i 平均 +0.000044i 差 *i1 / i 平均 +0.000168i 差 *i 10 / i 平均-1.441v1 / V+3.875v3 / V-2.320v5 / V-0.000011R1*i3 / i 平均 -0.00000002T*G 计 *i 差 *i1 / i 平均 -0.00000001T*G*i 差 *i2 / i 平均 +0.00000003T*G 计 *i 差 *i4 / i 平均 ;

[0112] In Example 4, f=27.46-0.283i1 / i 平均 +3.599i5 / i 平均 -15.47i7 / i 平均 -15.99i 10 / i 平均 -0.000030i 差 *i1 / i 平均 +0.000124i 差 *i9 / i 平均 +4.26v3 / V+11.24v4 / V-14.76v5 / V-0.340R1 / R2*i 10 / i 平均 ;

[0113] In Example 5, f=5.31-5.241i6 / i 平均 +0.000047i 差 *i1 / i 平均 +0.000187i 差 *i9 / i 平均 -1.72v1 / V+4.056v3 / V-2.394v5 / V-0.00000002T*G 计 *i 差 *i1 / i 平均 -0.00000001T*G*i 差 *i2 / i 平均 +0.00000003T*G 计 *i 差 *i4 / i 平均 ;

[0114] The HCT fitting equation in Comparative Example 1 is: HCT = -2.5*R^2 + 30.04*R-78.6;

[0115] HCT compensation equation: 初始=8.85*HCT^2-10.23*HCT+3.56;

[0116] Current temperature compensation equation: i=-0.0325*i 初始 ^2+4.89*i 初始 -120.75;

[0117] Current-reading equation: Reading = -0.564*i^2 + 5.889*i-4.716.

[0118] In order to verify the accuracy of the detection method of this embodiment, blood glucose was used as the target analyte and the following verification was performed:

[0119] 1. Determine the reference value of blood glucose concentration: Measure the reference value of blood glucose concentration using a YSI2300 glucose analyzer.

[0120] 2. Calculate the deviation: The deviation is a relative deviation, deviation = [(blood glucose concentration test value - blood glucose concentration reference value) / blood glucose concentration reference value] × 100%.

[0121] 3. Calculate the proportion of relative deviations within ±10%, ±15%, and ±20% respectively. The proportion calculation formula is: the number of deviations within ±10% (or ±15% or ±20%) / the total number of tests.

[0122] The test results are shown in Table 1, which shows the percentage of deviations of Examples 1-5 from the blood glucose concentration reference value within each range.

[0123] Table 1

[0124]

[0125]

[0126] As shown in Table 1, it can be seen that the analyte concentration calculated by the present invention has a deviation of more than 82% within ±10%, more than 91% within ±12.5%, and more than 96% within ±15% compared with the reference value of blood glucose concentration measured by the YSI2300 glucose analyzer, demonstrating that the present invention can effectively improve the accuracy and precision of blood glucose concentration in testing biological samples.

[0127] refer to Figure 3-7 As shown, the deviation comparison diagrams of Examples 1-5 before and after calibration are shown, wherein the deviation before calibration is G 计算 A deviation comparison diagram with a blood glucose concentration reference value is shown in the figure, which shows a deviation comparison diagram between the blood glucose concentration detection value G of the present invention and the blood glucose concentration reference value after calibration. Figure 8A comparison diagram of the deviations after calibration of Examples 1-5 is shown. It can be seen that the calibrated blood glucose concentration calculation method of the present invention comprehensively considers the mutual influence relationship between multiple interference factors related to blood glucose concentration, further improving the accuracy and precision of the blood glucose concentration in the tested biological sample.

[0128] Example 6

[0129] This embodiment relates to a method for testing uric acid concentration in a biological sample, which is applied to a biological sample analyte testing device. The biological sample analyte testing device includes an HCT detection electrode, a working electrode, and a counter electrode. The HCT electrode is free of any chemical reagent layer. The working electrode is coated with a chemical reagent that can chemically react with the analyte. An excitation signal is input to the working electrode. After the excitation signal is completed, the working electrode is in an open circuit state, and an attenuation signal of the counter electrode is collected.

[0130] The output current of the excitation signal is collected at regular intervals to obtain an output current group; the output voltage of the voltage collection point of the electrode attenuation signal is collected at regular intervals to obtain an output voltage group, and the analyte concentration G1 is calculated according to Formula 1:

[0131] G in Formula 1 计算 It is obtained by formula 2, and f in formula 1 is obtained by formula 3, where f is the multi-parameter calibration factor.

[0132] Among them, i 平均 is the average value of the output current of at least two current collection points in the excitation signal, nA; S is i 平均 The slope of the linear equation with analyte concentration. Where S is determined by the known history i 平均 and the historical analyte concentrations; or, the historical i of multiple batches of products 平均 After obtaining the linear relationship between the historical analyte concentrations and the historical analyte concentrations through statistical laws, they are directly tabulated and the slope S value is obtained by looking up the table.

[0133] Among them, i n and i j All are output currents in the output current group, nA; i 差 is the difference between the maximum output current of the excitation signal and the output current of the last acquisition point, nA; v o is the output voltage in the output voltage group, V; V is the excitation voltage of the excitation signal, V; the value range of N is 1-50; the value range of J is 1-50; X n The value range of X is 0-140; j The value range is -2-2; Xo The value range of is -2-0; the value range of K is 5-20, and the value range of O is 1-30.

[0134] Optionally, i n and i j It can be the output current of the continuous sampling points in the output current group. For example, i n It can be i1, i2, i3, i4, i5, i6, i7, i8, i9, i 10 ;i j It can be i6, i7, i8, i9, i 10 、i 11 、i 12 、i 13 、i 14 、i 15 .

[0135] Optionally, i n and i j It can be the output current of non-continuous sampling points in the output current group. For example, i n It can be i3, i5, i 11 、i 13 、i 21 ;i j It can be i1, i2, i9, i 17 、i 20 、i 29 、i 30 .

[0136] Optionally, v o It can be the output voltage of the continuous sampling points in the output voltage group. For example, v o Can be v1, v2, v3, v4, v5, v6, v7, v8, v9, v 10…… v 30 .

[0137] Optionally, v o The output current of the non-continuous sampling points in the output voltage group can be obtained. For example, v o Can be v1, v3, v6, v 11…… v 20 .

[0138] However, the present invention is not limited thereto, and those skilled in the art can select i according to the significance test method in mathematical statistics. n 、i j and v o value.

[0139] Optionally, the excitation time of the excitation signal is 3-6 s; preferably, the excitation time of the excitation signal is 5 s.

[0140] Optionally, i 平均 is the average value of the output current of the last three current acquisition points in the excitation signal.

[0141] Optionally, the voltage value of the excitation signal is 0.1-0.4V; preferably, the voltage value of the excitation signal is 0.3V.

[0142] Optionally, the output current of the current collection point of the excitation signal is collected every 0.1 s.

[0143] Optionally, the output attenuation voltage of the voltage collection point of the electrode attenuation signal is collected every 0.005 s.

[0144] Optionally, the voltage range of the electrode attenuation signal is 0-0.3V, and the attenuation signal is 1-30 continuous output signals; preferably, the attenuation signal is 20-30 continuous output signals.

[0145] In Example 6, f = -0.7883 -0.01279i2 / i average +0.0348i3 / i average +0.0541i4 / i 平均 -0.0797i5 / i 平均 -0.1861i9 / i 平均 +0.000004i 差 *i1 / i 平均 -0.000004i 差 *i2 / i 平均 -0.01893v1 / V+0.0395v2 / V-0.0860v3 / V+0.0500v4 / V

[0146] The test results are shown in Table 2, which shows the percentage of deviations between Example 6 and the reference value of uric acid concentration in each range.

[0147] Table 2

[0148]

[0149]

[0150] Figure 9 A comparison diagram of the deviation after calibration of Example 6 is shown. It can be seen that the calibrated uric acid concentration calculation method of the present invention comprehensively considers the mutual influence relationship between multiple interference factors related to uric acid concentration, further improving the accuracy and precision of testing uric acid concentration in biological samples.

[0151] The foregoing is merely an embodiment of the present application, and the scope of protection of the present application is not limited by these specific embodiments, but is determined by the claims of the present application. For those skilled in the art, various modifications and variations can be made to the present application. Any modifications, equivalent substitutions, improvements, etc. made within the technical ideas and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A method for testing the concentration of an analyte in a biological sample, characterized in that: Applicable to a biological sample analyte testing device, the biological sample analyte testing device comprises an HCT detection electrode, a working electrode and a counter electrode, the HCT electrode is free of any chemical reagent layer; the working electrode is covered with a chemical reagent that can react chemically with the analyte, an excitation signal is input to the working electrode, and after the excitation signal is completed, the working electrode is in an open circuit state, and the counter electrode attenuation signal is collected; Collecting the output current of the excitation signal at regular intervals to obtain an output current group; The output voltage of the voltage collection point of the electrode attenuation signal is collected at regular intervals to obtain an output voltage group, and the analyte concentration G1 is calculated according to the following formula: Among them, i 平均 is the average value of the output current of at least two current collection points in the excitation signal, nA; S is i 平均 The slope of the linear equation with respect to analyte concentration; i n and i j are the output currents in the output current group, nA; i 差 is the difference between the maximum output current of the excitation signal and the output current of the last acquisition point, nA; v o is the output voltage in the output voltage group, V; V is the excitation voltage of the excitation signal, V; the value range of N is 1-50; the value range of J is 1-50; X n The value range of X is 0-140; j The value range is -2-2; X o The value range of is -2-0; the value range of K is 5-20, and the value range of O is 1-30.

2. The calculation method according to claim 1, characterized in that: The method further includes applying a first alternating voltage to the HCT detection electrode before inputting an excitation signal to the working electrode to measure a first impedance value of the biological sample, and obtaining the analyte concentration G1 according to the output current group, the output voltage group and the first impedance value, wherein: Wherein, R1 is the first impedance value, Ω; i m is the output current in the output current group, nA; M ranges from 1 to 50; X m The value range is 0-100; Preferably, the method further comprises the step of obtaining the measured ambient temperature, and obtaining the analyte concentration G1 according to the output current group, the output voltage group, the first impedance value and the temperature, wherein: Where T is the ambient temperature, °C; i u is the output current in the output current group, nA; U ranges from 1 to 50; X u The value range is -1-1.

3. The calculation method according to claim 2, characterized in that: Between applying the first alternating voltage to the HCT detection electrode and inputting the excitation signal to the working electrode, the method further includes applying a second alternating voltage to the HCT detection electrode, wherein the frequencies of the first alternating voltage and the second alternating voltage are different, so as to measure the second impedance value of the biological sample, and obtain the analyte concentration G1 according to the output current group, the output voltage group, the first impedance value and the second impedance value, wherein: Wherein, R2 is the second impedance value, Ω; Preferably, the method further includes the step of obtaining the measured ambient temperature, and obtaining the analyte concentration G1 according to the output current group, the output voltage group, the first impedance value, the second impedance value and the temperature, wherein: Where T is the ambient temperature, °C; i u is the output current in the output current group, nA; U ranges from 1 to 50; X u The value range is -1-1.

4. The calculation method according to claim 3, characterized in that: The frequency of the first applied AC voltage is 1K Hz-100K Hz, and the frequency of the second applied AC voltage is 1K Hz-100K Hz; and / or The first AC voltage and the second AC voltage are applied discontinuously; Preferably, the frequency of the first applied AC voltage is 1 K Hz, and the frequency of the second applied AC voltage is 10 K Hz.

5. The calculation method according to any one of claims 1 to 4, characterized in that: The excitation time of the excitation signal is 3-6s; Preferably, the excitation time of the excitation signal is 5 s.

6. The calculation method according to any one of claims 1 to 4, characterized in that: i 平均 It is the average value of the output current of the last three current acquisition points in the excitation signal.

7. The calculation method according to any one of claims 1 to 4, characterized in that: The voltage value of the excitation signal is 0.1-0.4V; Preferably, the voltage value of the excitation signal is 0.3V.

8. The calculation method according to any one of claims 1 to 4, characterized in that: Collecting the output current of the current collection point of the excitation signal every 0.1 s; and / or The output attenuation voltage of the voltage collection point of the electrode attenuation signal is collected every 0.005 s.

9. The calculation method according to any one of claims 1 to 4, characterized in that: The voltage range of the electrode attenuation signal is 0-0.3V, and the attenuation signal is 1-30 continuous output signals; Preferably, the attenuation signal is 20-30 continuous output signals.

10. A sensor for testing the concentration of an analyte in a biological sample, characterized in that: The sensor is capable of performing the method for testing the concentration of an analyte in a biological sample as claimed in any one of claims 1 to 9.

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