A method and sensor for testing the concentration of an analyte in a biological sample

Abstract

The application discloses a method and a sensor for testing analyte concentration in a biological sample, and belongs to the technical field of instant detection of analyte concentration in a biological sample. The method inputs an excitation signal to the working electrode, and after the excitation signal is completed, the working electrode is in an open circuit state, and a counter electrode attenuation signal is collected; output currents of the excitation signal are collected every certain time, and an output current group is obtained; output voltages of voltage collection points of the counter electrode attenuation signal are collected every certain time, and an output voltage group is obtained, and the analyte concentration is calculated according to the parameters. The method excludes or weakens the mutual influence among various interference factors related to the analyte concentration, and can improve the accuracy, precision and anti-aging property of analyte concentration detection.

Description

Technical Field

[0001] This application relates to a method and sensor for testing the concentration of analytes in biological samples, belonging to the field of real-time detection technology of analyte concentration in biological samples. Background Technology

[0002] Traditional bioelectrochemical enzyme sensors achieve selectivity through a single biomolecular catalytic reaction, based on a two-chain reaction. In the second reaction (the combing 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 oxidized state → → biochemical reaction product + enzyme reduced 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, in a glucose or uric acid detection sensor system, the enzyme biomolecules catalyze the oxidation of glucose or uric acid molecules in the blood, while the added electron mediators react with the enzymes, converting the enzymes from a reduced state back to an oxidized state, thus playing a combing role.

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

[0008] Besides the aforementioned chemical interfering agents, electrochemical biosensors also experience other testing interferences. For example, hematocrit percentage (%-HCT) is a significant interfering factor. This interference occurs because the diffusion of electron mediators after the combusting reaction to the electrodes is hindered by blood cells, causing the diffusion coefficient to change with %-HCT. The current in the electrochemical reaction is affected by different %-HCT values; therefore, the factory batch calibration of sensor test strips is typically centered around 42% HCT. If the user's %HCT is higher than 42%, the test current or reading will show a negative deviation; conversely, if the user's %HCT is lower than 42%, the test current or reading will show a positive deviation. Furthermore, the aging effect of the test strips during storage can also interfere with blood glucose test results. That is, as storage time increases, the sensor's sensitivity relatively declines, and more oxidizable substances are generated that can provide background signals. Ambient temperature also contributes to interference.

[0009] Traditional electrochemical biosensors typically work by applying voltage to electrodes in contact with the analyte sample. This oxidizes the reduced electron mediators generated after the combusting reaction, producing a current signal in response to the analyte. The current signal is then converted into analyte concentration using appropriate calculation methods. Existing methods largely compensate for interference during the testing process by using different single parameters to eliminate or reduce interference, thereby improving accuracy and precision. However, these single-parameter interference compensation methods often overlook the interrelationships between multiple interference factors, such as the interaction between temperature and hematoxylin and eosin (HCT), the interaction between temperature and strip aging, the interaction between HCT and strip aging, and the interaction among temperature, current, and HCT, etc.

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

[0011] To address the aforementioned issues, a method and sensor for testing the concentration of analytes in biological samples are provided. This method inputs an excitation signal to the working electrode and calculates the concentration of the target analyte by fitting the input and output signals. This eliminates or reduces the mutual influence between various interfering factors related to analyte concentration, thereby improving the accuracy, precision, and anti-aging properties of analyte concentration detection.

[0012] According to one aspect of this application, a method for testing the concentration of an analyte in a biological sample is provided, applied to a biological sample analyte testing device, the biological sample analyte testing device including an HCT detection electrode, a working electrode, and a counter electrode, wherein the HCT electrode has no 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, collecting the attenuation signal of the counter electrode;

[0013] The output current of the excitation signal is collected at regular intervals to obtain an output current set; the output voltage of the voltage acquisition point of the counter electrode attenuation signal is collected at regular intervals to obtain an output voltage set. The analyte concentration G1 is calculated according to the following formula:

[0014]

[0015]

[0016]

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

[0018] Optionally, the method further includes the step of applying a first AC 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 based on the output current set, the output voltage set, and the first impedance value, wherein...

[0019]

[0020] Where R1 is the first impedance value, in Ω; i m The output current in the output current group is 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 based on the output current group, output voltage group, first impedance value, and temperature, wherein,

[0022]

[0023] Where T is the ambient temperature, in °C; i u The output current in the output current group is nA; the value of U ranges from 1 to 50; X u The value range is -1 to 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 a first AC voltage to the HCT detection electrode and inputting an excitation signal to the working electrode, a step of applying a second AC voltage to the HCT detection electrode is further included. The first AC voltage and the second AC voltage have different frequencies to measure a second impedance value of the biological sample. Based on the output current group, the output voltage group, the first impedance value, and the second impedance value, the analyte concentration G1 is obtained.

[0026]

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

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

[0029]

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

[0031] In the above calculation method, i n i j i m i uAll four currents are output currents in the output current group. In the calculation, the four currents can be the same, different, or partially the same. It is preferable that they are different because choosing different current values ​​increases the number of parameters in the calculation formula. This can reduce the large fluctuations in the overall result caused by the fluctuations of individual parameters, and improve the accuracy and repeatability of the result.

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

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

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

[0035] Discontinuous application can cause the interfering material to be oxidized under the first AC voltage application, thus reducing the influence of the interfering material on the test current after the second AC voltage application.

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

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

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

[0039] Optionally, i 平均 This is the average value of the output current at 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 acquisition point of the excitation signal is acquired every 0.1s.

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

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

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

[0046] According to another aspect of this application, a sensor for testing the concentration of an analyte in a biological sample is provided, the sensor being capable of performing the method for testing the concentration of an analyte in a biological sample as described in any of the preceding claims.

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

[0048] 1. The method for testing the concentration of analytes in biological samples in this application can solve the technical problem that the existing method of using a single parameter for interference compensation often ignores the mutual influence between multiple interference factors, resulting in low accuracy and precision of analyte concentration testing.

[0049] 2. The method for testing the concentration of analytes in biological samples in this application introduces a new attenuation electrical signal and a dual-frequency impedance test signal in addition to the traditional oxidation current signal. This eliminates or reduces the mutual influence between various interference factors related to the concentration of analytes, and further improves the accuracy and precision of testing the concentration of analytes in biological samples.

[0050] 3. The method for testing the concentration of analytes in biological samples in this application takes into account the interaction between various interfering factors related to the concentration of analytes, and eliminates or reduces the influence of the above-mentioned interfering factors, thus making it possible to achieve test strips without the need for code adjustment at the factory. Attached Figure Description

[0051] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

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

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

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

[0055] Figure 4 A comparison chart of deviations before and after calibration in Example 2 is shown;

[0056] Figure 5 A comparison chart of deviations before and after calibration in Example 3 is shown;

[0057] Figure 6 A comparison chart of deviations before and after calibration in Example 4 is shown;

[0058] Figure 7 A comparison chart of deviations before and after calibration in Example 5 is shown;

[0059] Figure 8 The following diagram shows a comparison of the deviations after calibration in Examples 1-5;

[0060] Figure 9 A comparison chart of deviations after calibration in Example 6 is shown. Detailed Implementation

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

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

[0063] The excitation described in this application applies an input signal to the electrodes in a bioassay device (e.g., a sensor). This applied signal includes positive and negative DC constant voltage or positive and negative DC constant current sources, causing a complete or partial oxidation or reduction reaction on the electrode surface. The bioassay device system applies the excitation input signal to the corresponding electrode through the connection between the instrument and the test strip. After a predetermined excitation time, the system stops applying a signal to the electrode, and the electrode is in an open-circuit state. An open-circuit state is not zero input; for example, applying 0V (zero volts) to the working electrode does not equate to an open circuit. Zero voltage is also a type of input voltage. When the electrode is in an open-circuit state, the redox substances on and near the electrode surface cause a decay process in the remaining signal. This decay signal reflects the state that the electrode has experienced, thereby recording other information related to the analyte concentration from the bioassay device.

[0064] Example 1

[0065] This embodiment relates to a method for testing blood glucose concentration in biological samples, 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 has no chemical reagent layer. The working electrode is covered with a chemical reagent that can 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, collecting the attenuation signal from the counter electrode.

[0066] The output current of the excitation signal is collected at regular intervals to obtain the output current set; the output voltage of the voltage acquisition point of the counter electrode decay signal is collected at regular intervals to obtain the output voltage set. The analyte concentration G1 is calculated according to Equation 1:

[0067] G in Equation 1 计算The value of f in Equation 1 is obtained by Equation 3, where f is a multi-parameter calibration factor.

[0068] Among them, i 平均 The average value of the output current i at at least two current acquisition points in the excitation signal is nA; S is the average value of i. 平均 The slope of the linear equation relating analyte concentration and analyte concentration. Where S is derived from known historical values ​​of i. 平均 The concentrations were obtained by linear fitting with historical analyte concentrations; or, historical data from multiple batches of products. 平均 After obtaining the linear relationship between the concentrations of historical analytes and their statistical properties, a table was created, and the slope S value was 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 nA is the difference between the maximum output current of the excitation signal and the output current of the last acquisition point; v o V is the output voltage in the output voltage group; V is the excitation voltage of the excitation signal; N ranges from 1 to 50; J ranges from 1 to 50; X n The value range of X is 0-140; j The value range of X is -2 to -2; o The value range of is -2 to 0; the value range of K is 5 to 20; and the value range of O is 1 to 30.

[0070] Optionally, i n and i j This can be the output current of continuously sampled 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 This can be the output current of discontinuous 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, i17 i 20 i 29 i 30 .

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

[0073] Optionally, v o This can be the output current at discontinuous sampling points in the output voltage group. For example, v o It 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 3-6s; preferably, the excitation time of the excitation signal is 5s.

[0076] Optionally, i 平均 This is the average value of the output current at 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 acquisition point of the excitation signal is acquired every 0.1s.

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

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

[0081] Example 2

[0082] This embodiment, based on Embodiment 1, further includes a step of applying a first AC voltage to the HCT detection electrode before inputting an excitation signal to the working electrode, to measure the first impedance value of the biological sample. Based on the output current group, output voltage group, and the first impedance value, the analyte concentration G1 is obtained.

[0083]

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

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

[0086] Example 3

[0087] This embodiment, based on Embodiment 2, further includes a step of obtaining the measured ambient temperature. Based on the output current group, output voltage group, first impedance value, and temperature, the analyte concentration G1 is obtained.

[0088]

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

[0090] Example 4

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

[0092]

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

[0094] Optionally, the frequency of the applied second AC voltage is 1 kHz to 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 a step of obtaining the measured ambient temperature. Based on the output current group, output voltage group, first impedance value, second impedance value, and temperature, the analyte concentration G1 is obtained.

[0097]

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

[0099] Comparative Example 1

[0100] This comparative example obtains the test temperature T, blood glucose test current value, and impedance value R. It processes these values ​​to obtain the temperature-compensated impedance value and temperature-compensated current value for blood glucose. Based on the HCT fitting equation, the temperature-compensated impedance value is fitted to obtain the HCT value. Then, the HCT value is converted into i based on the HCT compensation equation. 初始 Then, by combining the current temperature compensation equation (to obtain i) and the current-reading value equation, the final blood glucose reading is obtained.

[0101] Experimental Example

[0102] The sensor capable of performing the above embodiments and the comparative analyte concentration calculation method is used to detect the blood sample to be tested. The sensor is equipped with a calculation module, which includes a calculation formula. The method and process of storing the calculation module are existing technologies and can be implemented by those skilled in the art, and will not be described in detail in this embodiment.

[0103] In this testing method, the test time and potential are controlled as follows:

[0104] (1) Pre-test gap 1.5 seconds; During the test gap, the first AC voltage and the 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 1K Hz, the application time is 0.4 seconds, the interval is 0.7 seconds, and the second AC voltage is applied. The frequency of the second AC voltage is 10K Hz, the application time is 0.4 seconds.

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

[0106] (3) After the excitation signal ends, the working electrode is set to 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. (Reference) Figure 1 As shown, Figure 1 A schematic diagram of the main excitation signals is shown. Figure 1 The horizontal axis represents the sensor test time, and the vertical axis represents the excitation signal strength, which is the voltage applied to the electrodes.

[0108] refer to Figure 2 As shown, Figure 2 History i is shown 平均 The graph shows a linear relationship with historical analyte concentrations, with a slope S of 29.74. In Examples 1-3, i... 平均 This is the average value of the output current at 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: i 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] To verify the accuracy of the detection method in this embodiment, blood glucose was used as the target analyte, and the following verification was performed:

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

[0120] 2. Calculate the deviation: The deviation is a relative deviation, and the deviation is calculated as follows: Deviation = [(detected blood glucose concentration value - reference blood glucose concentration value) / reference blood glucose concentration value] × 100%.

[0121] 3. Calculate the percentage of each of the three relative deviation ranges: ±10%, ±15%, and ±20%. The percentage is calculated as: 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 between Examples 1-5 and the reference values ​​for blood glucose concentration in each range.

[0123] Table 1

[0124]

[0125]

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

[0127] refer to Figure 3-7 As shown, the deviation comparison charts before and after calibration for Examples 1-5 are presented respectively. In the charts, the deviation before calibration represents G. 计算 The graph shows the deviation between the detected blood glucose concentration G and the reference value after calibration. Figure 8 The diagram shows a comparison of deviations after calibration in Examples 1-5. It can be seen that the blood glucose concentration calculation method after calibration in this invention comprehensively considers the mutual influence between various interference factors related to blood glucose concentration, further improving the accuracy and precision of blood glucose concentration in biological samples.

[0128] Example 6

[0129] This embodiment relates to a method for testing the concentration of uric acid in biological samples, 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 has no chemical reagent layer. The working electrode is covered with a chemical reagent that can 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, collecting the attenuation signal from the counter electrode.

[0130] The output current of the excitation signal is collected at regular intervals to obtain the output current set; the output voltage of the voltage acquisition point of the counter electrode decay signal is collected at regular intervals to obtain the output voltage set. The analyte concentration G1 is calculated according to Equation 1:

[0131] G in Equation 1 计算 The value of f in Equation 1 is obtained by Equation 3, where f is a multi-parameter calibration factor.

[0132] Among them, i 平均 The average value of the output current i at at least two current acquisition points in the excitation signal is nA; S is the average value of i. 平均 The slope of the linear equation relating analyte concentration and analyte concentration. Where S is derived from known historical values ​​of i. 平均 The concentrations were obtained by linear fitting with historical analyte concentrations; or, historical data from multiple batches of products. 平均 After obtaining the linear relationship between the concentrations of historical analytes and their statistical properties, a table was created, and the slope S value was 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 nA is the difference between the maximum output current of the excitation signal and the output current of the last acquisition point; v o V is the output voltage in the output voltage group; V is the excitation voltage of the excitation signal; N ranges from 1 to 50; J ranges from 1 to 50; X n The value range of X is 0-140; j The value range of X is -2 to -2; o The value range of is -2 to 0; the value range of K is 5 to 20; and the value range of O is 1 to 30.

[0134] Optionally, i n and i j This can be the output current of continuously sampled points in the output current group. For example, i n It can be i1, i2, i3, i4, i5, i6, i7, i8, i9, i 10i 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 This can be the output current of discontinuous 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 This can be the output voltage of continuously sampled points in the output voltage group. For example, v o It can be v1, v2, v3, v4, v5, v6, v7, v8, v9, v 10…… v 30 .

[0137] Optionally, v o This can be the output current at discontinuous sampling points in the output voltage group. For example, v o It 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 3-6s; preferably, the excitation time of the excitation signal is 5s.

[0140] Optionally, i 平均 This is the average value of the output current at 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 acquisition point of the excitation signal is acquired every 0.1s.

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

[0144] Optionally, the voltage range of the electrode attenuation signal is 0-0.3V, and the attenuation signal is 1-30 consecutive output signals; preferably, the attenuation signal is 20-30 consecutive 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 for uric acid concentration in each range.

[0147] Table 2

[0148]

[0149]

[0150] Figure 9 The diagram showing the deviation comparison after calibration in Example 6 demonstrates that the calibrated uric acid concentration calculation method of the present invention comprehensively considers the mutual influence between various interfering factors related to uric acid concentration, further improving the accuracy and precision of testing uric acid concentration in biological samples.

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

Claims

1. A method for testing the concentration of an analyte in a biological sample, characterized in that, A biological sample analyte testing device is used, which includes an HCT detection electrode, a working electrode, and a counter electrode. The HCT electrode has no chemical reagent layer. The working electrode is covered with a chemical reagent that can 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 to collect the attenuation signal from the counter electrode. The output current of the excitation signal is collected at regular intervals to obtain the output current group; The output voltage of the voltage acquisition point of the counter electrode attenuation signal is collected at regular intervals to obtain the output voltage set. The analyte concentration G1 is then calculated according to the following formula: ， ， ， Among them, i 平均 The value of the output current at at least two current acquisition points in the excitation signal is nA; S is i 平均 The slope of the linear equation with respect to analyte concentration; i n and i j All are output currents in the output current group, nA; i 差 nA is the difference between the maximum output current of the excitation signal and the output current of the last acquisition point; v o V is the output voltage in the output voltage group; V is the excitation voltage of the excitation signal; N ranges from 1 to 50; J ranges from 1 to 50; X n The value range of X is 0-140; j The value range of X is -2 to -2; o The value range of is -2 to 0; the value range of K is 5 to 20; and the value range of O is 1 to 30.

2. The method according to claim 1, characterized in that, The method also includes the step of applying a first AC voltage to the HCT detection electrode before inputting an excitation signal to the working electrode, in order to measure a first impedance value of the biological sample, and obtaining the analyte concentration G1 based on the output current set, the output voltage set, and the first impedance value, wherein... ， Where R1 is the first impedance value, in Ω; i m The output current in the output current group is nA; M ranges from 1 to 50; X m The value range is 0-100.

3. The method according to claim 2, characterized in that, It also includes the step of obtaining the measured ambient temperature, and obtaining the analyte concentration G1 based on the output current group, output voltage group, first impedance value, and temperature, wherein, Where T is the ambient temperature, in °C; i u The output current in the output current group is nA; the value of U ranges from 1 to 50; X u The value range is -1 to 1.

4. The method according to claim 2, characterized in that, Between applying a first AC voltage to the HCT detection electrode and inputting an excitation signal to the working electrode, a step of applying a second AC voltage to the HCT detection electrode is included. The first AC voltage and the second AC voltage have different frequencies to measure the second impedance value of the biological sample. Based on the output current group, output voltage group, first impedance value, and second impedance value, the analyte concentration G1 is obtained. ， Wherein, R2 is the second impedance value, in Ω.

5. The method according to claim 4, characterized in that, It also includes the step of obtaining the measured ambient temperature, and obtaining the analyte concentration G1 based on the output current group, output voltage group, first impedance value, second impedance value, and temperature, wherein, Where T is the ambient temperature, in °C; i u The output current in the output current group is nA; the value of U ranges from 1 to 50; X u The value range is -1 to 1.

6. The method according to claim 4, characterized in that, 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; and / or The first AC voltage and the second AC voltage are applied discontinuously.

7. The method according to claim 6, characterized in that, The frequency of the first AC voltage applied is 1 kHz, and the frequency of the second AC voltage applied is 10 kHz.

8. The method according to any one of claims 1-7, characterized in that, The excitation time of the excitation signal is 3-6 seconds.

9. The method according to claim 8, characterized in that, The excitation time of the excitation signal is 5 seconds.

10. The method according to any one of claims 1-7, characterized in that, i 平均 This is the average value of the output current at the last three current acquisition points in the excitation signal.

11. The method according to any one of claims 1-7, characterized in that, The voltage value of the excitation signal is 0.1-0.4V.

12. The method according to claim 11, characterized in that, The voltage value of the excitation signal is 0.3V.

13. The method according to any one of claims 1-7, characterized in that, The output current of the current acquisition point of the excitation signal is acquired every 0.1s; and / or The output attenuation voltage of the voltage acquisition point of the electrode attenuation signal is collected every 0.005s.

14. The method according to any one of claims 1-7, characterized in that, The voltage range of the electrode attenuation signal is 0-0.3V, and the attenuation signal is 1-30 consecutive output signals.

15. The method according to claim 14, characterized in that, The attenuation signal consists of 20-30 consecutive output signals.

16. 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 analytes in biological samples as described in any one of claims 1-15.

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