A rapid method for the detection of glucose and metformin hydrochloride

Abstract

The application discloses a rapid detection method of glucose and metformin hydrochloride, which comprises the following steps: using a differential pulse voltammetry method, using an electrochemical sensor provided by the application to detect the oxidation peak current value of a glucose and / or metformin hydrochloride sample solution, and calculating the concentration of glucose and / or metformin hydrochloride in the sample solution according to a standard curve equation. The detection method in the application realizes simultaneous quantitative detection of two analytes, namely glucose and metformin hydrochloride, on the same sensor by using a differential pulse voltammetry method, and has the advantages of multi-element detection, fast detection speed, accurate detection result, low cost and the like compared with traditional methods of detecting glucose or metformin hydrochloride alone.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of detection, and particularly relates to a rapid detection method for glucose and metformin hydrochloride. BACKGROUND

[0002] Diabetes is a serious global chronic disease. Therefore, diabetic patients need to frequently self-test blood glucose concentration to monitor their own health condition and reduce the risk of diabetes and its complications. Metformin hydrochloride, as a first-line clinical drug for treating type II diabetes, can effectively improve the sensitivity of human body's own insulin and has a significant blood glucose lowering effect. At present, the means for detecting blood glucose is a sensor modified by glucose oxidase, which is prone to enzyme inactivation and is not suitable for long-term storage. Common detection means for metformin drugs mainly include instrument detection methods such as high performance liquid chromatography, capillary electrophoresis and fluorescence analysis. Although these methods have high sensitivity, they are expensive, have a long detection period and need to be operated by professional personnel, which is not conducive to rapid detection. In addition, the existing detection methods can only detect glucose or metformin hydrochloride alone and cannot realize the purpose of distinguishing and rapidly detecting glucose and metformin hydrochloride on the same sensor by using the same detection method. SUMMARY

[0003] In order to overcome the problems existing in the prior art, one of the purposes of the present application is to provide an electrochemical sensor for detecting glucose and metformin hydrochloride.

[0004] The second purpose of the present application is to provide a rapid detection method for glucose and metformin hydrochloride.

[0005] The third purpose of the present application is to provide a detection system for glucose and metformin hydrochloride.

[0006] The fourth purpose of the present application is to provide the application of the above-mentioned electrochemical sensor in the detection of uric acid, lactic acid, dopamine or cholesterol.

[0007] In order to achieve the above-mentioned purposes, the technical solution adopted by the present application is as follows:

[0008] The first aspect of the present application provides an electrochemical sensor for detecting glucose and metformin hydrochloride, comprising a working electrode, the working electrode comprising a film coating and an electrode material, the electrode material being provided with a film coating, the film coating containing an iron-based nanomaterial and a film-forming aid; the film-forming aid comprising a perfluorosulfonic acid type polymer.

[0009] The film-forming aid in the present application can enhance the stability and durability of the film coating.

[0010] Preferably, the film coating further contains a conductive material; the conductive material includes at least one of graphene oxide, carbon nanotubes, and black phosphorus.

[0011] Preferably, the iron-based nanomaterial includes Fe2O3.

[0012] When the iron-based nanomaterial in the present invention detects glucose and metformin hydrochloride, trivalent iron electrocatalytically oxidizes glucose or metformin hydrochloride to generate electrons that are transferred to the working electrode surface. The concentrations of glucose and metformin hydrochloride are then obtained by measuring the oxidation peak current values ​​of glucose and metformin hydrochloride.

[0013] Preferably, the preparation method of the iron-based nanomaterial is: mixing an iron salt with an alkaline solution to obtain a precipitate; and calcining the precipitate at a temperature of 450 to 550°C.

[0014] Preferably, the iron salt is ferric chloride.

[0015] Preferably, the alkali solution is at least one of ammonia water, sodium hydroxide, and potassium hydroxide; more preferably, the alkali solution is ammonia water.

[0016] Preferably, the calcination temperature is 480-520°C; more preferably, the calcination temperature is 490-510°C.

[0017] Preferably, the film coating is prepared by mixing the iron-based nanomaterial and a film-forming aid to obtain a suspension; and then drying the suspension to form a film on the surface of the electrode material to obtain the film coating.

[0018] Preferably, the mass ratio of the iron-based nanomaterial to the film-forming aid is 1:(0.8-1.2); further preferably, the mass ratio of the iron-based nanomaterial to the film-forming aid is 1:1.

[0019] Preferably, the step of drying the suspension to form a film on the surface of the electrode material is to dry the suspension to form a film on the surface of the electrode material using a drop coating process, thereby forming a film coating.

[0020] Preferably, the method for preparing the membrane coating further comprises the step of adding a conductive material for mixing; the step of adding a conductive material for mixing is located before the step of drying the suspension to form a film on the surface of the electrode material.

[0021] Preferably, the electrode material is a glassy carbon electrode material, a carbon electrode material, a platinum electrode material or a gold electrode material.

[0022] The electrochemical sensor also includes a reference electrode and a counter electrode.

[0023] Preferably, the reference electrode is silver / silver chloride.

[0024] Preferably, the counter electrode is a platinum electrode.

[0025] Preferably, the electrochemical sensor works in an electrolyte solution.

[0026] Preferably, the electrolyte solution is a PBS solution.

[0027] Preferably, the pH of the PBS solution is 6.9-7.1; further preferably, the pH of the PBS solution is 7.0.

[0028] Preferably, the concentration of the PBS solution is 0.08-1.2 mol / L; further preferably, the concentration of the PBS solution is 0.1 mol / L.

[0029] The second aspect of the present application provides a rapid detection method of glucose and metformin hydrochloride, comprising the following steps:

[0030] The oxidation peak current value of the sample solution is detected by using the electrochemical sensor provided in the first aspect of the present application by differential pulse voltammetry, and the concentration of glucose and / or metformin hydrochloride in the sample solution is calculated according to the standard curve equation.

[0031] The method for measuring glucose and metformin hydrochloride in the present application is for measuring the concentration of glucose and / or metformin hydrochloride in a sample for non-diagnostic purposes.

[0032] The method in the present application is a method for measuring glucose and / or metformin hydrochloride in blood, urine, interstitial fluid or saliva for non-diagnostic purposes.

[0033] Preferably, the method for obtaining the standard curve equation is as follows: the oxidation peak current value of glucose or metformin hydrochloride with different concentrations is detected by using the electrochemical sensor by differential pulse voltammetry, and then a linear relationship between the concentration and the oxidation peak current value is established to obtain the standard curve equation.

[0034] Preferably, the differential pulse voltammetry is as follows: the initial voltage is -0.3 to -0.5 V, the terminal electrode is 0.8-1.2 V, the pulse amplitude is 0.01-0.1 V, the pulse width is 0.04-0.06 s, the sampling width is 0.01-0.02 s, the pulse cycle is 0.4-0.6 s, and the standing time is 1-5 s.

[0035] Preferably, the initial voltage is -0.3 to -0.4 V; further preferably, the initial voltage is -0.2 V.

[0036] Preferably, the voltage of the termination electrode is 0.9 to 1.2 V; further preferably, the voltage of the termination electrode is 0.9 to 1.1 V; and even further preferably, the voltage of the termination electrode is 1 V.

[0037] Preferably, the pulse amplitude is 0.01 to 0.08V, more preferably, the pulse amplitude is 0.04 to 0.06V; even more preferably, the pulse amplitude is 0.05V.

[0038] Preferably, the pulse width is 0.02 to 0.05 s; further preferably, the pulse width is 0.03 to 0.05 s; even further preferably, the pulse width is 0.05 s.

[0039] The electrochemical sensor provided in the first aspect of the present invention and the detection method provided in the second aspect can both be used to detect metformin, and there is no difference in the detection conditions for metformin and metformin hydrochloride.

[0040] The third aspect of the present invention provides a glucose and metformin hydrochloride detection system, comprising the electrochemical sensor provided by the first aspect of the present invention.

[0041] The detection system of the present invention includes the above electrochemical sensor. The detection system can simultaneously perform quantitative and qualitative detection of glucose and metformin hydrochloride, or perform qualitative and quantitative detection of glucose or metformin hydrochloride separately by using the above electrochemical sensor.

[0042] The fourth aspect of the present invention provides use of the electrochemical sensor provided in the first aspect of the present invention in the detection of uric acid, lactic acid, dopamine or cholesterol.

[0043] The beneficial effects of the present invention are as follows: the electrochemical sensor of the present invention can realize simultaneous quantitative and qualitative detection of glucose and metformin hydrochloride, and can also perform qualitative and quantitative detection of glucose or metformin hydrochloride separately, with accurate detection results and fast detection speed, and can measure low concentrations of metformin hydrochloride.

[0044] The detection method of the present invention uses differential pulse voltammetry to achieve simultaneous quantitative detection of two analytes, namely glucose and metformin hydrochloride, on the same sensor. Compared with traditional methods such as single detection of glucose or metformin hydrochloride, it has the advantages of multiplex detection, fast detection speed, accurate detection results, and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is the standard curve diagram for the detection of glucose in the present invention.

[0046] Figure 2 It is the detection standard curve diagram of metformin hydrochloride in the present invention.

[0047] Figure 3 This is the SEM image of the iron-based nanomaterial in Example 1.

[0048] Figure 4 This is the DPV response curve of glucose solutions with different concentrations in Example 1.

[0049] Figure 5 This is the DPV response curve of metformin hydrochloride solutions of different concentrations in Example 2.

[0050] Figure 6 This is the DPV response curve of metformin hydrochloride and glucose in Example 3. DETAILED DESCRIPTION

[0051] The specific implementation of the present invention is further described in detail below with reference to the accompanying drawings and examples, but the implementation and protection of the present invention are not limited thereto. It should be noted that if there are any processes that are not particularly described in detail below, they can be implemented or understood by those skilled in the art with reference to the prior art. If the manufacturer of the reagents or instruments used is not indicated, they are deemed to be conventional products that can be purchased commercially.

[0052] The concentrations of metformin hydrochloride and glucose in Examples 1 to 3 of the present invention are quantitatively analyzed using a standard curve method. First, standard curves of metformin hydrochloride and glucose are drawn respectively. After the DPV response curves of metformin hydrochloride and / or glucose in the sample are detected, the concentrations of metformin hydrochloride and glucose can be calculated based on the standard curves, thereby achieving quantitative analysis of the concentrations of metformin hydrochloride and glucose. The standard curve for glucose detection is shown in FIG. Figure 1 As shown, the linear equation for glucose is y = 3.56e -8 x+1.18e -6 , where R 2 =0.9989, the detection sensitivity is 3.56e -8 A / (mmol / L). The standard curve of metformin hydrochloride is as follows Figure 2 As shown, the linear equation of metformin hydrochloride is y = 1.36e -8 x+7.07e -7 , where R 2 =0.9830, the detection sensitivity is 1.36e -8 A / (μmol / L).

[0053] Example 1

[0054] The rapid glucose detection method in this example includes the following steps:

[0055] (1) Preparation of iron-based nanomaterials

[0056] Dissolve 100mg of FeCl3·6H2O powder in 20mL of distilled water and stir evenly. Under stirring, gradually add 25% NH4OH solution to the solution at a dropping speed of 0.2mL / min. The pH value of the solution is maintained at 8.0. Filter the obtained brown solid precipitate, rinse with water to remove excess alkali in the precipitate, dry in a 60℃ oven for about 12 hours, and finally calcine in a muffle furnace at 500℃ for 5 hours to obtain Fe2O3 nanomaterials, i.e., iron-based nanomaterials. The SEM image of the iron-based nanomaterial is shown in Figure 2. Figure 3 shown.

[0057] (2) Preparation of detection electrodes

[0058] 1 mg of Fe2O3 nanomaterials and 200 μL of 0.5% Nafion solution were dispersed in 800 μL of 0.1 mmol / L, pH 7.0 PBS solution. After ultrasonication for 30 minutes, a uniform suspension was obtained. 6 μL of the suspension was cast on the surface of a newly polished gold electrode and evaporated at room temperature to form a stable film to prepare the detection electrode.

[0059] (3) Construction of electrochemical sensors and detection

[0060] The prepared detection electrode was used as the working electrode, silver / silver chloride as the reference electrode, and the platinum electrode as the counter electrode to construct an electrochemical sensor.

[0061] Cyclic voltammetry was performed in a PBS solution with a concentration of 0.1 mol / L and a pH of 7.0 to obtain the redox curve of the PBS solution. As a blank control group, it was observed that the PBS solution had an obvious oxidation peak at -0.2 V.

[0062] The electrochemical sensor was sequentially inserted into PBS test solutions containing different concentrations of glucose, and scanned using DPV (differential pulse voltammetry). The parameters were set as initial voltage -0.4V, end voltage 1V, pulse amplitude 0.05V, pulse width 0.05s, sampling width 0.0167s, pulse period 0.5s, and rest time 2s. The DPV response curves and oxidation peaks of glucose at different concentrations were recorded. The oxidation peak of glucose was -0.2V. The specific test results are shown in Figure 2. Figure 4 The PBS test solutions containing different concentrations of glucose used in this example are: PBS solution containing 2 mmol / L glucose, PBS solution containing 4 mmol / L glucose, PBS solution containing 6 mmol / L glucose, PBS solution containing 8 mmol / L glucose, and PBS solution containing 10 mmol / L glucose. The PBS solution is a 0.1 mol / L PBS solution with a pH of 7.0.

[0063] Depend on Figure 4 It can be seen that as the glucose concentration increases, the oxidation peak of glucose also gradually increases, which indicates that the electrochemical sensor in this example has a good response to different concentrations of glucose. It further shows that the detection method of the present invention can independently detect different concentrations of glucose. The time required from the start of detection to the detection result is 3 minutes, which can achieve rapid and accurate detection of the glucose content.

[0064] Example 2

[0065] The rapid detection method for metformin hydrochloride in this example includes the following steps:

[0066] The detection electrode prepared in Example 1 was used as the working electrode, the silver / silver chloride was used as the reference electrode, and the platinum electrode was used as the counter electrode to construct an electrochemical sensor.

[0067] Cyclic voltammetry scanning was performed in a 0.1 mol / L PBS solution with a pH of 7.0. As the redox curve of the blank control group, it can be observed that the PBS solution has an obvious oxidation peak at -0.2V.

[0068] The electrochemical sensor was sequentially inserted into PBS test solutions containing different concentrations of metformin hydrochloride, and scanned using DPV (differential pulse voltammetry). The parameters were set as initial voltage -0.4V, end voltage 1V, pulse amplitude 0.05V, pulse width 0.05s, sampling width 0.0167s, pulse period 0.5s, and standing time 2s. The DPV response curves and oxidation peaks of metformin hydrochloride at different concentrations were recorded. The specific test results are shown in Figure 2. Figure 5 As shown. The PBS test solutions containing different concentrations of metformin hydrochloride used in this example are: PBS solution containing 20 μmol / L metformin hydrochloride, PBS solution containing 40 μmol / L metformin hydrochloride, PBS solution containing 60 μmol / L metformin hydrochloride, PBS solution containing 80 μmol / L metformin hydrochloride, and PBS solution containing 100 μmol / L metformin hydrochloride, wherein the PBS solution is a 0.1 mol / L PBS solution with a pH of 7.0.

[0069] Depend on Figure 5 It can be seen that metformin hydrochloride has an obvious oxidation peak at 0.15V, and as the concentration of metformin hydrochloride increases, the peak value gradually increases, indicating that the electrochemical sensor in this example has a good response to different concentrations of metformin hydrochloride. It further shows that the detection method of the present invention can independently detect different concentrations of metformin hydrochloride. The time required from the start of detection to the detection result is 3 minutes, which can achieve rapid and accurate detection of the content of metformin hydrochloride.

[0070] Example 3

[0071] The rapid detection method for glucose and metformin hydrochloride in this example includes the following steps:

[0072] The detection electrode prepared in Example 1 was used as the working electrode, the silver / silver chloride was used as the reference electrode, and the platinum electrode was used as the counter electrode to construct an electrochemical sensor.

[0073] Cyclic voltammetry scanning was performed in a 0.1 mol / L PBS solution with a pH of 7.0. As the redox curve of the blank control group, it can be observed that the PBS solution has an obvious oxidation peak at -0.2V.

[0074] The electrochemical sensor was sequentially inserted into PBS test solutions containing 80 μmol / L metformin hydrochloride and 7 mmol / L glucose. The DPV (differential pulse voltammetry) method was used for scanning. The parameters were set as initial voltage -0.4 V, end voltage 1 V, pulse amplitude 0.05 V, pulse width 0.05 s, sampling width 0.0167 s, pulse period 0.5 s, and standing time 2 s. The DPV response curves and oxidation peaks of metformin hydrochloride and glucose were recorded. The specific test results are shown in Figure 2. Figure 6 The PBS solution used in this example is a 0.1 mol / L PBS solution with a pH of 7.0.

[0075] Depend on Figure 6 It is known that the electrochemical sensor in this example can detect glucose and metformin hydrochloride simultaneously, and all have good response, wherein, metformin hydrochloride has obvious oxidation peak at 0.15V, and glucose has obvious oxidation peak at -0.2V, and the detection method in the present invention can be used to realize the distinction and detection of metformin hydrochloride and glucose simultaneously, and can be well distinguished between metformin hydrochloride and glucose, and the two will not affect each other's test result. In addition, using the method in the present invention, the oxidation peak of metformin hydrochloride and glucose is constantly increased along with the increase of concentration, and the concentration of metformin hydrochloride and glucose can be calculated according to the current size of the oxidation peak detected, and the time required for detecting the concentration of metformin hydrochloride and glucose from the beginning is within 3min, and then show that the detection method in the present invention can realize the detection of metformin hydrochloride and glucose to different concentrations simultaneously, and has good responsiveness, can detect the concentration of metformin hydrochloride and glucose quickly and accurately.

[0076] While the embodiments of the present invention have been described in detail above, the present invention is not limited to the embodiments described above. Various modifications may be made within the scope of knowledge possessed by a person skilled in the art without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof may be combined with one another unless there is a conflict.

Claims

1. An electrochemical sensor for detecting glucose and metformin hydrochloride, characterized in that: The invention comprises a working electrode, which comprises a membrane coating and an electrode material. The electrode material is provided with a membrane coating, and the membrane coating contains an iron-based nanomaterial and a film-forming aid. The film-forming aid comprises a perfluorosulfonic acid polymer. The iron-based nanomaterial comprises Fe2O3.

2. The electrochemical sensor for detecting glucose and metformin hydrochloride according to claim 1, wherein: The preparation method of the iron-based nanomaterial comprises the following steps: mixing iron salt and alkali solution to obtain a precipitate; and calcining the precipitate at a temperature of 450-550°C.

3. The electrochemical sensor for detecting glucose and metformin hydrochloride according to claim 1, wherein: The electrode material is a glassy carbon electrode material, a carbon electrode material, a platinum electrode material or a gold electrode material.

4. The electrochemical sensor for detecting glucose and metformin hydrochloride according to claim 1, wherein: The electrochemical sensor further comprises a reference electrode and a counter electrode; the reference electrode is silver / silver chloride; and the counter electrode is a platinum electrode.

5. A rapid detection method for glucose and metformin hydrochloride, characterized in that: The following steps are involved: The differential pulse voltammetry method is adopted, and the electrochemical sensor according to any one of claims 1 to 4 is used to detect the oxidation peak current value of the sample solution, and the concentration of glucose and / or metformin hydrochloride in the sample solution is calculated according to the standard curve equation.

6. The rapid detection method for glucose and metformin hydrochloride according to claim 5, characterized in that: The method for obtaining the standard curve equation is: using the differential pulse voltammetry method, using the electrochemical sensor to detect the oxidation peak current values ​​of glucose or metformin hydrochloride standards with different concentrations, and then establishing a linear relationship between the concentration and the oxidation peak current value to obtain the standard curve equation.

7. The rapid detection method for glucose and metformin hydrochloride according to claim 5 or 6, characterized in that: The differential pulse voltammetry method is specifically as follows: the initial voltage is -0.3 to -0.5 V, the termination electrode is 0.8 to 1.2 V, the pulse amplitude is 0.01 to 0.1 V, the pulse width is 0.04 to 0.06 s, the sampling width is 0.01 to 0.02 s, the pulse period is 0.4 to 0.6 s, and the standing time is 1 to 5 s.

8. A glucose and metformin hydrochloride detection system, characterized in that: The electrochemical sensor comprises the electrochemical sensor according to any one of claims 1 to 4.

9. Use of the electrochemical sensor according to any one of claims 1 to 4 in the detection of uric acid, lactic acid, dopamine or cholesterol.

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