Method for distinguishing quality control solution from biological sample

Abstract

A method for distinguishing a quality control solution from a biological sample, which method belongs to the technical field of electrochemical tests. The method for distinguishing a quality control solution from a biological sample comprises: making a working electrode come into contact with a sample to be tested, wherein the working electrode is a blank electrode or is covered with an inert substance that does not produce a chemical reaction with a biological sample; inputting an excitation signal sequence into the working electrode, wherein the excitation signal sequence comprises at least two consecutive or non-consecutive input signals, and each input signal is at a constant value; and respectively measuring an output signal sequence of a quality control solution and an output signal sequence of the biological sample in response to the excitation signal sequence, so as to distinguish the quality control solution from the biological sample. The method solves the problem whereby manually adjusting a quality control solution mode may lead to misoperation during a quality control process of existing electrode-type blood test apparatuses; in actual use, it is no longer necessary to perform mode setting on a quality control solution sample or a biological sample, thereby improving the usage convenience, and thus avoiding adverse results caused by misoperation; and there is no special requirement for the quality control solution, thereby facilitating the application and popularization.

Description

A method for distinguishing quality control solution from biological samples

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on December 28, 2023, with application number "202311854180.5" and invention name "A method for distinguishing quality control fluid from biological samples", the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of biological sample analysis, and in particular to a method for distinguishing quality control fluid from biological samples. Background Art

[0003] Quantitative determination of the concentrations of important substances in human blood, such as blood glucose, blood ketones, blood lactate, cholesterol, uric acid, triglycerides, etc., is very important for clinical diagnosis and health management. At present, electrochemical testing systems are mainly used to determine the concentration of target analytes in blood. By modifying biological molecules (such as enzymes) on the surface of electrodes to selectively identify target analytes in the blood, the biorecognition signal is converted into an electrical signal (oxidation or reduction current) that can be collected and measured in the blood testing device, thereby achieving quantitative detection of the target analyte.

[0004] To ensure the reliability and accuracy of the electrochemical testing system in determining the concentration of target analytes in the blood, it is necessary to perform quality control tests on the electrochemical testing system regularly to determine whether the testing system is working properly. For example, common blood glucose testing systems are equipped with blood glucose control fluid. The operator needs to use the blood glucose testing system to measure the blood glucose control fluid after a certain period of time. If the measured value exceeds the quality control concentration range of the blood glucose control fluid, it indicates that the reliability of the blood glucose testing system is reduced and it cannot be used for clinical testing.

[0005] The quality control measurement mode of a common electrochemical test system is that the operator manually selects the quality control liquid measurement mode on the electrochemical tester, installs the electrochemical test device electrodes into the electrochemical tester, and adds quality control liquid to the electrochemical test device electrodes. In this operating mode, the operator needs to manually switch the tester between the two measurement modes of quality control liquid or actual sample (such as blood, urine). If the actual sample measurement is performed in the quality control liquid mode, or the quality control liquid measurement is performed in the actual sample measurement mode without changing the test mode, there may be a risk of inaccurate instrument inspection results and test results, affecting the operator's ability to make correct clinical judgments. In addition, when the measurer manages the measurement values, the measurement results of the quality control liquid that are not needed in the management data will be mixed together, and the measurement values ​​cannot be properly managed.

[0006] Chinese patent CN116165252A discloses a method, application, and device for automatically identifying quality control fluid and samples. It discloses applying an AC voltage to electrodes and detecting the impedance value of the sample to be tested to determine whether the sample to be tested is a quality control fluid or a sample. However, the method provided in this patent requires that the quality control fluid must contain lithium salt, and even has requirements for the mass concentration of the lithium salt, which imposes certain limitations on daily applications. Summary of the Invention

[0007] In order to solve the above problems, a method for distinguishing quality control fluid from biological samples is provided. An excitation signal sequence is input into a blank electrode or a working electrode covered with an inert substance that does not chemically react with the biological sample, and the output signal sequence of the excitation signal sequence is measured to distinguish the quality control fluid from the biological sample. The purpose is to solve the problem that manual adjustment of the quality control fluid mode may cause operational errors during the quality control process of the existing electrode-type blood testing device. In actual use, there is no need to set the mode of the quality control fluid sample or the biological sample, which improves the convenience of use and avoids adverse results caused by misoperation. There are no special requirements for the quality control fluid, which facilitates application and promotion.

[0008] According to one aspect of the present application, a method for distinguishing a quality control solution from a biological sample is provided, wherein a working electrode is contacted with a sample to be tested, wherein the working electrode is a blank electrode or is covered with an inert substance that does not chemically react with the biological sample;

[0009] Inputting an excitation signal sequence to the working electrode, wherein the excitation signal sequence includes at least two continuous or discontinuous input signals, and each of the input signals is a constant value;

[0010] The output signal sequence of the sample to be tested in response to the excitation signal sequence is measured to distinguish the quality control solution from the biological sample.

[0011] Optionally, the excitation signal sequence includes at least two continuously applied input signals, and the output voltage of the excitation signal sequence continuously increases or continuously decreases, and the voltage range is 0.1 to 3V.

[0012] Optionally, the excitation signal sequence includes 4-8 consecutive input signals.

[0013] Specifically, this form of input signal can obtain multiple data feedback from the working electrode, reduce errors, and save detection steps, thereby reducing the difficulty of testing.

[0014] Optionally, the excitation signal sequence includes 5 consecutive input signals, and voltage values ​​of the 5 consecutive input signals are 0.3V, 0.8V, 1.2V, 1.7V, and 2.0V, respectively.

[0015] Optionally, the excitation signal sequence includes at least two non-continuously applied input signals, and the output voltage of the excitation signal sequence increases or decreases discontinuously, with a voltage range of 0.1 to 3V.

[0016] Optionally, the excitation signal sequence includes 4-8 non-continuous input signals.

[0017] Optionally, the excitation signal sequence includes 6 non-continuous input signals, and voltage values ​​of the 6 non-continuous input signals are 0.3V, 0.8V, 0.6V, 1.1V, 1.0V, and 1.8V, respectively.

[0018] Optionally, the total application time of the excitation signal sequence is at least 1 s, and the voltage range is 0.2 to 2.2V.

[0019] Specifically, the total application time of the excitation signal sequence is short, which can improve test efficiency.

[0020] Optionally, the application time of each input signal in the excitation signal sequence is 0.1-0.3 s.

[0021] Optionally, the application time of each input signal in the excitation signal sequence is equal, that is, 0.2 s.

[0022] Optionally, at least one parameter is calculated from the output signal sequence of the working electrode, and the tested sample is determined to be a quality control fluid or a biological sample based on a predetermined quality control fluid detection critical value.

[0023] Optionally, at least two parameters are calculated from the output signal sequence of the working electrode, and the sample being tested is determined to be a quality control fluid or a biological sample based on a predetermined two-dimensional critical value for quality control fluid detection.

[0024] Optionally, at least two different parameter groups are calculated from the output signal sequence of the working electrode, and the tested sample is determined to be a quality control solution or a biological sample based on two predetermined two-dimensional critical values ​​of quality control solution detection.

[0025] Optionally, the biological sample includes blood, urine, saliva, bile, gastric juice, lymph and the like.

[0026] The beneficial effects of this application include but are not limited to:

[0027] 1. According to the method of distinguishing quality control fluid from biological samples in the present application, an excitation signal sequence is input to a blank electrode or a working electrode covered with an inert substance that does not chemically react with the biological sample, and the output signal sequence of the excitation signal sequence is measured to distinguish the quality control fluid from the biological sample; its purpose is to solve the problem that manual adjustment of the quality control fluid mode may cause operational errors during the quality control process of the existing electrode-type blood testing device. In actual use, there is no need to set the mode of the quality control fluid sample or the biological sample, which improves the convenience of use and avoids adverse results caused by misoperation. There are no special requirements for the quality control fluid, which is convenient for application and promotion.

[0028] 2. According to the method of distinguishing quality control fluid from biological samples in the present application, this method can be used to determine the type of sample, such as whether the sample is a whole blood sample or a quality control fluid. The sample type is identified by comparing one-dimensional or multi-dimensional parameters, and the quality control fluid is automatically separated from the whole blood sample database, thereby more accurately summarizing and analyzing the whole blood samples at different time periods, providing comprehensive data for disease treatment.

[0029] 3. According to the method of distinguishing quality control liquid from biological samples of the present application, by setting the working electrode as a blank electrode or covering it with an inert substance that does not chemically react with the biological sample, and not covering it with a chemical agent that can react with the analyte, at a low excitation potential (≤1.2V), there are basically not many oxidizable objects, so the output current is quite low, but the decay rate of the output current varies with different liquid qualities. At a high excitation potential (>1.2V), the buffer component of the sample itself will become oxidizable, thereby giving a different output current. These intuitive manifestations can be reflected by extracting different parameters to distinguish quality control liquid from biological samples. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] 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:

[0031] FIG1 is a schematic diagram of a working electrode excitation signal sequence according to an embodiment of the present application;

[0032] FIG2 is a schematic diagram of four different step wave excitation waveforms involved in an embodiment of the present application;

[0033] FIG3 is a diagram of output signals generated by the quality control solution and the whole blood sample under step wave excitation according to an embodiment of the present application;

[0034] FIG4 is a two-dimensional parameter combination diagram of the current generated by the working electrode extracted from the whole blood sample and the quality control solution involved in Example 1 of the present application;

[0035] FIG5 is a line graph of the output signal current ratio and current ratio difference generated by the quality control solution and blood under step wave excitation involved in Example 1 of the present application;

[0036] FIG6 is a two-dimensional parameter combination diagram of the current generated by the working electrode extracted from the whole blood sample and the quality control solution involved in Example 2 of the present application;

[0037] FIG7 is a line graph of the output signal current ratio and current ratio difference generated by the quality control solution and blood involved in Example 2 of the present application under step wave excitation. DETAILED DESCRIPTION

[0038] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0039] Unless otherwise defined, all professional and scientific terms used herein have the same meaning as those familiar to those skilled in the art. The reagents or raw materials used in this application can be purchased through conventional channels. Unless otherwise specified, the reagents or raw materials used in this application are used in a conventional manner in the art or according to the product instructions. In addition, any method and material similar to or equivalent to the described content can be applied to the method of this application. The preferred implementation methods and materials described in this patent are for demonstration purposes only.

[0040] With reference to FIG1 , an embodiment of the present application discloses a working electrode excitation signal sequence, wherein the duration of each excitation in the excitation signal sequence may be between 0.05 and 0.5 seconds, and may be a continuous excitation sequence without intervals, or may be composed of different excitation pulses with intervals. Optionally, the excitation signal sequence is a continuous excitation sequence without intervals. It is understandable that the continuous excitation sequence may be a continuously growing excitation sequence, or an excitation sequence that first increases and then decreases, first increases and then decreases and then increases, etc. Optionally, the continuous excitation sequence is a continuously growing excitation sequence. If the excitation signal sequence is a voltage, the voltage value is between 0.1 and 3V. The excitation series signal shown in FIG1 includes 5 excitations, and the excitation voltages of the 5 excitations are 0.3V, 0.8V, 1.2V, 1.7V, and 2.2V, respectively, and the duration of each excitation may be 0.2 seconds. Each excitation lasts for 0.2 seconds, and the output current signal is synchronously measured at intervals of 0.05 seconds. This excitation series signal may be referred to as a "step wave."

[0041] Referring to Figure 2, in addition to the excitation signal sequence implemented on the working electrode as shown in Figure 1, other different excitation series signals, namely step waves, can also be implemented. Figure 2 shows several different step wave cases: Figure 2A is Case 2, namely Step Wave 2: the excitation voltage of the excitation signal increases continuously by three steps, then drops back by one step and then increases continuously by four steps. The voltages of the excitation signals are 0.3V, 0.7V, 1.1V, 0.9V, 1.2V, 1.5V, 1.9V, and 2.3V, respectively. The voltage of each excitation signal lasts for 0.15 seconds. Figure 2B is Case 3, namely Step Wave 3: the excitation voltage of the excitation signal increases continuously by three steps, then drops back by one step, then increases continuously by three steps, then drops back by one step, and then increases continuously by three steps. The voltages of the excitation signals are 0.3V, 0.6V, 0.9V, 0.8 ... 1.1V, 1.4V, 1.7V, 1.6V, 1.9V, 2.3V, 2.7V, with each excitation signal voltage lasting 0.15 seconds. Figure 2C shows Case 4, or Step Wave 4: the excitation signal sequence has different growth rates for the first and last excitation signals. The excitation signal voltages are 0.3V, 0.5V, 0.7V, 0.9V, 1.2V, 1.6V, 2.0V, and 2.4V, respectively, with each voltage lasting 0.15 seconds. Figure 2D shows Case 5, or Step Wave 5: the excitation signal sequence is discontinuous, with each excitation pulse signal separated by a short open circuit interval that does not exceed 50% of the pulse excitation time. The excitation signal voltages are 0.3V, 0.8V, 1.2V, 1.7V, and 2.2V, respectively, with each excitation pulse lasting 0.15 seconds, and there is a 0.05 second open circuit interval between pulses.

[0042] Excitation signal sequences in Cases 2, 3, and 4 can capture output signals at relatively low excitation intensities and relatively high excitation intensities. For example, when the input signal is a potential, a range of 0.3-1.2V is more suitable for measuring common chemicals in a sample, while an input signal between 1.2-3.0V will stimulate chemicals that require high excitation intensities, such as hematocrit. Finally, a series of discrete, spaced pulse excitation signals can produce relatively distinct output signals.

[0043] Figure 3 shows the output signals generated by a control solution and a whole blood sample under staircase wave excitation. The current signal values ​​can be coded as in,m, according to the order in which the output current signals appear, where n is the nth excitation in the staircase wave and m is the mth current signal output under the nth excitation. The staircase wave is applied to the working electrode, which is either a blank electrode or coated with an inert material that does not chemically react with the biological sample and is not covered with chemicals that could react with the analyte. Therefore, the current signal generated by the staircase wave is entirely derived from other oxidizable substances in the sample. The currents shown in Figure 3 are from a 50 mg / dL whole blood sample and a 50 mg / dL control solution. At low excitation potentials (≤1.2V), there are essentially no oxidizable substances present, resulting in a very low output current. However, the rate of output current decay varies depending on the fluid type. At high excitation potentials (>1.2V), the sample's buffer components become oxidizable, resulting in different output currents. These characteristics can be visualized by extracting various parameters.

[0044] In addition, the parameters can be extracted from the output current of the step wave and defined as follows:

[0045] Step wave: The first, second, third, fourth and fifth step waves are defined as tp1, tp2, tp3, tp4 and tp5 respectively;

[0046] Endpoint current ratio: The endpoint current ratio of each step voltage is defined as: RT1 = i1,4 / i1,1, RT2 = i2,4 / i2,1, RT3 = i3,4 / i3,1, RT4 = i4,4 / i4,1, RT5 = i5,4 / i5,1;

[0047] Front-end two current ratio: The front-end two current ratio of each step is defined as: RT12=i1,2 / i1,1, RT22=i2,2 / i2,1, RT32=i3,2 / i3,1, RT42=i4,2 / i4,1, RT52=i5,2 / i5,1;

[0048] Back-end two current ratio: The back-end two current ratio of each step is defined as: RT14=i1,4 / i1,3, RT24=i2,4 / i2,3, RT34=i3,4 / i3,3, RT44=i4,4 / i4,3, RT54=i5,4 / i5,3;

[0049] Back-end current ratio difference: RT14-RT12, RT24-RT22, RT34-RT32, RT44-RT42, RT54-RT52. From the parameters defined above, select the parameter that can be used to distinguish whole blood samples from quality control solution.

[0050] Example 1

[0051] Five continuous input signals were sequentially applied to the working electrode. The voltage values ​​of the five input signals were 0.3 V, 0.8 V, 1.2 V, 1.7 V, and 2.0 V, respectively. The application time of the five input signals was equal, each lasting 0.2 s. These five continuous input signals were the excitation signal sequence. The output current was measured to obtain the step current ratio and current difference (RTx). This RTx was the output sequence signal.

[0052] The voltage values ​​of the five input signals are 0.3V, 0.8V, 1.2V, 1.7V, and 2.0V, respectively. There are four sampling points in each voltage application stage. When the voltage value of 0.3V is input, it is the first segment, and the sampling values ​​are i11, i12, i13, and i14 in order; when the voltage value of 0.8V is input, it is the second segment, and the sampling values ​​are i21, i22, i23, and i24 in order; when the voltage value of 1.2V is input, it is the third segment, and the sampling values ​​are i31, i32, i33, and i34 in order; when the voltage value of 1.7V is input, it is the fourth segment, and the sampling values ​​are i41, i42, i43, and i44 in order; when the voltage value of 2.0V is input, it is the fifth segment, and the sampling values ​​are i51, i52, i53, and i54 in order.

[0053] End-point current ratio: The end-point current ratio of each voltage segment is defined as: RT1 = i14 / i11, RT2 = i24 / i21, RT3 = i34 / i31, RT4 = i44 / i41, RT5 = i54 / i51.

[0054] Front-end two current ratio: The front-end two current ratio of each segment is defined as: RT12 = i12 / i11, RT22 = i22 / i21, RT32 = i32 / i31, RT42 = i42 / i41, RT52 = i52 / i51.

[0055] Back-end two current ratio: The back-end two current ratio of each section is defined as: RT14 = i14 / i13, RT24 = i24 / i23, RT34 = i34 / i33, RT44 = i44 / i43, RT54 = i54 / i53.

[0056] Back-end to front-end current ratio difference: RT14-RT12, RT24-RT22, RT34-RT32, RT44-RT42, RT54-RT52.

[0057] Figure 4 shows a two-dimensional parameter combination diagram of the current generated by the working electrode in this embodiment, extracted from a whole blood sample and a control solution. This two-dimensional parameter combination diagram, extracted from the output signal, is used to distinguish between whole blood samples and control solution analysis samples. As can be seen in Figures 4A, 4B, and 4C, the current signal generated by the step wave can be combined into multiple sets of two-dimensional parameters to distinguish between the control solution and the biological sample.

[0058] Blood and control fluid were tested using the steps of Example 1. Two groups of experiments were performed on the blood, namely b1 and b2, and sixteen groups of experiments were performed on the control fluid, namely c11, c12, c13, c14, c15, c16, c17, c18, c21, c22, c23, c24, c25, c26, c27, and c28. RT1, RT2, RT3, RT4, RT5, RT34-RT32 were recorded for each group. The results are shown in Figure 5. Figure 5 shows the output signal data generated by the control fluid and blood under step wave excitation. The data in Figure 5 shows that the four parameters RT2, RT4, RT5, and RT34-RT32 have the greatest difference between blood and control fluid, and blood and control fluid can be clearly distinguished based on these four parameters.

[0059] Example 2

[0060] Six non-continuous input signals were sequentially applied to the working electrode. The voltage values ​​of the six non-continuous input signals were 0.3 V, 0.8 V, 0.6 V, 1.1 V, 1.0 V, and 1.8 V, respectively. The six input signals were applied for equal durations of 0.2 s each, with an interval of 0.1 s. These six non-continuous input signals constituted the excitation signal sequence. The output current was measured to obtain the step current ratio and current difference (RTx). This RTx constituted the output sequence signal.

[0061] The voltage values ​​of the six input signals are 0.3V, 0.8V, 0.6V, 1.1V, 1.0V, and 1.8V, respectively. Each voltage application stage has four sampling points. When the voltage value of 0.3V is input, it is the first stage, and the sampling values ​​are i11, i12, i13, and i14 in order; when the voltage value of 0.8V is input, it is the second stage, and the sampling values ​​are i21, i22, i23, and i24 in order; when the voltage value of 0.6V is input, it is the second stage, and the sampling values ​​are i21, i22, i23, and i24 in order; It is the third segment, and the sampling values ​​are i31, i32, i33, and i34 in order; when the voltage value of 1.1V is input, it is the fourth segment, and the sampling values ​​are i41, i42, i43, and i44 in order; when the voltage value of 1.0V is input, it is the fifth segment, and the sampling values ​​are i51, i52, i53, and i54 in order; when the voltage value of 1.8V is input, it is the sixth segment, and the sampling values ​​are i61, i62, i63, and i64 in order.

[0062] End-point current ratio: The end-point current ratio of each voltage segment is defined as: RT1 = i14 / i11, RT2 = i24 / i21, RT3 = i34 / i31, RT4 = i44 / i41, RT5 = i54 / i51, RT6 = i64 / i61.

[0063] Front-end two current ratio: The front-end two current ratio of each segment is defined as: RT12 = i12 / i11, RT22 = i22 / i21, RT32 = i32 / i31, RT42 = i42 / i41, RT52 = i52 / i51; RT62 = i62 / i61.

[0064] Back-end two current ratio: The back-end two current ratio of each section is defined as: RT14 = i14 / i13, RT24 = i24 / i23, RT34 = i34 / i33, RT44 = i44 / i43, RT54 = i54 / i53, RT64 = i64 / i63.

[0065] Back-end to front-end current ratio difference: RT14-RT12, RT24-RT22, RT34-RT32, RT44-RT42, RT54-RT52, RT64-RT62.

[0066] Figure 6 shows a two-dimensional parameter combination diagram of the current generated by the working electrode in this embodiment, extracted from a whole blood sample and a control solution. This two-dimensional parameter combination diagram, extracted from the output signal, is used to distinguish between whole blood samples and control solution as an analytical sample. As can be seen in Figures 6A, 6B, 6C, and 6D, the current signal generated by the step wave can be combined into multiple sets of two-dimensional parameters to distinguish between the control solution and the biological sample.

[0067] Blood and control fluid were tested using the steps of Example 2. Two groups of experiments were performed on the blood, namely b1 and b2, and sixteen groups of experiments were performed on the control fluid, namely c11, c12, c13, c14, c15, c16, c17, c18, c21, c22, c23, c24, c25, c26, c27, and c28. RT2, RT3, RT4, RT5, RT6, RT54-RT52, and RT44-RT42 were recorded for each group. The results are shown in Figure 7. Figure 7 shows the output signal data generated by the control fluid and blood under step wave excitation. The data in Figure 7 shows that the five parameters RT2, RT3, RT6, RT54-RT52, and RT44-RT42 are the most different for blood and control fluid, and blood and control fluid can be clearly distinguished based on these four parameters.

[0068] 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, the present application may have various modifications and variations. 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 differentiating a quality control fluid from a biological sample, wherein, Bring the working electrode into contact with the sample to be tested, where the working electrode is a blank electrode or is covered with an inert substance that does not chemically react with biological samples; Input an excitation signal sequence to the working electrode, where the excitation signal sequence includes at least two consecutive or non - consecutive input signals, and each input signal is a constant value; Measure the output signal sequence of the sample to be tested in response to the excitation signal sequence to distinguish the quality control liquid and biological samples.

2. The method for differentiating a quality control liquid from a biological sample according to claim 1, wherein, The excitation signal sequence includes at least two consecutively applied input signals, and the output voltage of the excitation signal sequence continuously increases or continuously decreases, with a voltage range of 0.1 - 3V.

3. A method for differentiating a quality control fluid from a biological sample according to claim 2, wherein, The excitation signal sequence includes 4 - 8 consecutive input signals.

4. A method for differentiating a quality control fluid from a biological sample according to claim 2 or 3, wherein, The excitation signal sequence includes 5 consecutive input signals, and the voltage values of the 5 consecutive input signals are 0.3V, 0.8V, 1.2V, 1.7V, and 2.0V respectively.

5. A method for differentiating a quality control liquid from a biological sample according to claim 1, wherein, The excitation signal sequence includes at least two non - consecutively applied input signals, and the output voltage of the excitation signal sequence non - continuously increases or non - continuously decreases, with a voltage range of 0.1 - 3V.

6. A method for differentiating a quality control fluid from a biological sample according to claim 5, wherein, The excitation signal sequence includes 4 - 8 non - consecutive input signals.

7. A method for differentiating a quality control liquid from a biological sample according to claim 5 or 6, wherein The excitation signal sequence includes 6 non - consecutive input signals, and the voltage values of the 6 non - consecutive input signals are 0.3V, 0.8V, 0.6V, 1.1V, 1.0V, and 1.8V respectively.

8. A method for differentiating a quality control fluid from a biological sample according to claim 1, wherein, The total application time of the excitation signal sequence is at least 1s, and the voltage range is 0.2 - 2.2V.

9. A method for differentiating a quality control fluid from a biological sample according to claim 8, wherein, The application time of each input signal in the excitation signal sequence is 0.1 - 0.3s.

10. A method for differentiating a quality control fluid from a biological sample according to claim 9, wherein, The application time of each input signal in the excitation signal sequence is equal, all being 0.2s.

11. A method for differentiating a quality control liquid from a biological sample according to claim 1, wherein, Calculate at least one parameter from the output signal sequence of the working electrode, and determine whether the tested sample is a quality control liquid or a biological sample according to a predetermined critical value for quality control liquid detection.

12. A method for differentiating a quality control fluid from a biological sample according to claim 1, wherein, Calculate at least two parameters from the output signal sequence of the working electrode, and determine whether the tested sample is a quality control liquid or a biological sample according to a predetermined two - dimensional critical value for quality control liquid detection.

13. A method for differentiating a quality control liquid from a biological sample according to claim 1, wherein, Calculate at least two different parameter sets from the output signal sequence of the working electrode, and determine whether the tested sample is a quality control liquid or a biological sample according to two predetermined two - dimensional critical values for quality control liquid detection.

14. A method for differentiating a quality control liquid from a biological sample according to claim 1, wherein, The biological samples include samples such as blood, urine, saliva, bile, gastric juice, lymph fluid, etc.

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