A preparation method of an electrochemical sensor for simultaneously detecting creatinine and uric acid

Abstract

The application discloses a preparation method of an electrochemical sensor for simultaneously detecting creatinine and uric acid, and relates to the technical field of medical detection. The technical scheme points of the application are as follows: ethanol, ethylene glycol and deionized water are uniformly mixed, then carbon nanotubes and anhydrous copper acetate are uniformly mixed with the mixture, and then the mixture is subjected to hydrothermal reaction, and after the reaction is completed and the mixture is cooled, the carbon nanotube / copper oxide / cuprous oxide nanocomposite is obtained by purification. In the application, the electrochemical sensor prepared by using the copper nanoparticle-related carbon nanocomposite can enhance the electron transmission capacity, thereby improving the electrochemical activity; meanwhile, the application can be used for detecting two biological molecules of creatinine and uric acid, has a low detection limit and a wide detection linear range, the creatinine detection limit is 0.002mM, the detection range is 0.01mM-1mM, the uric acid detection limit is 0.0004mM, and the detection range is 0.001mM-5mM.

Description

Technical Field

[0001] This invention relates to the field of medical testing technology, and more specifically, to a method for preparing an electrochemical sensor for the simultaneous detection of creatinine and uric acid. Background Technology

[0002] Various molecules within a living organism are closely related to human health. Significant deviations from normal levels in these molecules often indicate metabolic abnormalities and the onset of certain diseases. Therefore, the detection of these biomolecules is an effective way to assess a person's health status. Creatinine is a naturally occurring metabolic product that is filtered from the blood by the kidneys at a constant rate. Serum creatinine concentration is an important indicator for evaluating kidney function, diagnosing acute kidney injury and chronic kidney disease. It can also serve as an indicator of muscle mass loss; serum creatinine levels significantly exceeding normal levels indicate severe kidney damage. Uric acid is produced through the body's purine metabolism pathway. When the concentration of uric acid in the body rises above its solubility, the resulting uric acid crystals can lead to various diseases, including gout, Lesch-Nyhan syndrome, kidney disease, hypertension, and cardiovascular disease. Therefore, accurate detection of creatinine and uric acid plays a crucial role in the control and treatment of these diseases.

[0003] Electrochemical sensing technology, as an emerging technology for biomolecule detection, has advantages such as high sensitivity, low detection limit, strong selectivity, and simple operation. Therefore, the use of electrochemical sensing technology for the detection of various biomolecules has attracted great interest. For example, electrodes modified with nanomaterials such as platinum nanoparticles, nanoporous gold, graphene / gold nanoparticles, or graphene carbon nitride nanosheets are used to determine creatinine or uric acid. However, some of these methods have low sensitivity or narrow linear range, or the electrode preparation is complicated.

[0004] Therefore, the present invention aims to provide a method for preparing an electrochemical sensor for simultaneously detecting creatinine and uric acid, in order to solve the aforementioned problems. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing an electrochemical sensor for the simultaneous detection of creatinine and uric acid, in order to solve the problems of low sensitivity, narrow linear range, or complex electrode preparation in the existing methods mentioned above.

[0006] The above-mentioned technical objective of the present invention is achieved through the following technical solution: a method for preparing an electrochemical sensor for simultaneously detecting creatinine and uric acid, the preparation method comprising the following steps:

[0007] S1: Ethanol, ethylene glycol and deionized water are mixed evenly to obtain the first mixed solution;

[0008] S2: The carbon nanotubes and anhydrous copper acetate are uniformly mixed with the first mixed solution to obtain the second mixed solution;

[0009] S3: Perform a hydrothermal reaction on the second mixed solution. After the reaction is completed and the solution is cooled, purify the solution to obtain the carbon nanotube / copper oxide / cuprous oxide nanocomposite.

[0010] S4: Disperse the carbon nanotube / copper oxide / cuprous oxide nanocomposite in deionized water and mix it evenly to obtain a suspension;

[0011] S5: The suspension is drop-coated onto the surface of the glassy carbon electrode and dried at room temperature;

[0012] S6: Nafion solution is drop-coated onto the dried glassy carbon electrode surface, and the electrochemical sensor is obtained after drying.

[0013] The present invention is further configured such that the volume fraction ratio of ethanol, ethylene glycol and deionized water in step S1 is 2:5:3.

[0014] The present invention is further configured such that the mass concentration ratio of the carbon nanotubes and anhydrous copper acetate in step S2 is 1:3-15.

[0015] The present invention is further configured such that the optimal mass concentration ratio of the carbon nanotubes and anhydrous copper acetate in step S2 is 1:7.

[0016] The present invention is further configured such that: the hydrothermal reaction temperature in step S3 is 100-150℃, and the hydrothermal reaction time is 4-12h.

[0017] The present invention is further configured such that: the optimal temperature for the hydrothermal reaction in step S3 is 120°C, and the hydrothermal reaction time is 8 hours.

[0018] The present invention is further configured such that the specific purification steps in step S3 are: centrifuging the cooled product with deionized water and ethanol, washing it, and then drying it.

[0019] The present invention is further configured such that: the concentration of the carbon nanotube / copper oxide / cuprous oxide nanocomposite in the suspension in step S4 is 1 mg / ml in deionized water, and the amount of the suspension dropped onto the glassy carbon electrode surface in step S5 is 10 μL.

[0020] The present invention is further configured such that: the concentration of the Nafion solution in step S6 is 0.05wt% to 5wt%, the amount used for drop coating onto the glassy carbon electrode surface is 5μL, and the optimal concentration is 0.5wt%.

[0021] The present invention also provides an electrochemical sensor for the simultaneous detection of creatinine and uric acid.

[0022] In summary, the present invention has the following beneficial effects:

[0023] 1. In this invention, by employing an electrochemical sensor prepared from a carbon nanocomposite associated with copper nanoparticles, electron transport capability can be enhanced, thereby improving electrochemical activity. Simultaneously, this invention can be used for the detection of two biomolecules, creatinine and uric acid, exhibiting low detection limits and a wide linear detection range. The detection limit for creatinine is 0.002 mM, with a detection range of 0.01 mM to 1 mM; the detection limit for uric acid is 0.0004 mM, with a detection range of 0.001 mM to 5 mM.

[0024] 2. The method for preparing the electrochemical sensor for simultaneous detection of creatinine and uric acid provided in this invention is simple, flexible, highly sensitive, has strong anti-interference ability, and is highly efficient, and is particularly suitable for the detection of creatinine and uric acid. Attached Figure Description

[0025] Figure 1 This is a flowchart of a method for preparing an electrochemical sensor for simultaneously detecting creatinine and uric acid, as described in Embodiment 1 of the present invention.

[0026] Figure 2 This is a schematic flowchart of a method for preparing an electrochemical sensor for simultaneously detecting creatinine and uric acid according to Embodiment 1 of the present invention.

[0027] Figure 3 The data curves obtained in Example 2 of this invention are shown below: (a) is the differential pulse voltammetry curve corresponding to different creatinine concentrations; (b) is the linear relationship between the oxidation peak current intensity of the corresponding creatinine-copper ion complex and the corresponding creatinine concentration at different creatinine concentrations; (c) is the differential pulse voltammetry curve corresponding to different uric acid concentrations; and (d) is the linear relationship between the oxidation peak current intensity of the corresponding uric acid-copper ion complex and the corresponding uric acid concentration at different uric acid concentrations).

[0028] Figure 4 The data curves obtained in Example 2 of this invention are shown below: (a) is the differential pulse voltammetry curve of creatinine and uric acid at different concentrations simultaneously; (b) is the linear relationship between the oxidation peak current intensity of the corresponding uric acid-copper ion complex and the corresponding uric acid concentration; (c) is a partial magnified view of the differential pulse voltammetry curve of creatinine at different concentrations simultaneously measured in uric acid and creatinine; (d) is the linear relationship between the oxidation peak current intensity of the corresponding creatinine-copper ion complex and the corresponding creatinine concentration). Detailed Implementation

[0029] The following is in conjunction with the appendix Figure 1-4 The present invention will be described in further detail below.

[0030] Example 1

[0031] A method for preparing an electrochemical sensor for simultaneous detection of creatinine and uric acid, such as... Figure 1 , Figure 2 As shown, the preparation method includes the following steps:

[0032] S1: Ethanol, ethylene glycol and deionized water are mixed evenly to obtain the first mixed solution;

[0033] It should be noted that the volume fraction ratio of ethanol, ethylene glycol and deionized water in step S1 above is 2:5:3.

[0034] S2: Carbon nanotubes with a mass concentration ratio of 1:7 and anhydrous copper acetate are uniformly mixed with the first mixed solution, and then sonicated for 10 minutes to obtain the second mixed solution.

[0035] S3: Perform a hydrothermal reaction on the second mixed solution. After the reaction is completed and the solution is cooled, purify the solution to obtain the carbon nanotube / copper oxide / cuprous oxide nanocomposite.

[0036] It should be noted that the hydrothermal reaction temperature in step S3 above is 120℃ and the hydrothermal reaction time is 8h.

[0037] It should be noted that the specific purification steps in step S3 above are to centrifuge the cooled product with deionized water and ethanol, wash it at least three times, and then dry it.

[0038] S4: Disperse the carbon nanotube / copper oxide / cuprous oxide nanocomposite in deionized water, mix evenly to obtain a suspension, and the concentration of the carbon nanotube / copper oxide / cuprous oxide nanocomposite in the suspension in deionized water is 1 mg / ml.

[0039] S5: Take a bare glassy carbon electrode, polish its surface, drop 10μL of suspension onto the surface of the glassy carbon electrode, and dry it at room temperature.

[0040] S6: Drop 5 μL of 0.5 wt% Nafion solution onto the dried glassy carbon electrode surface. After drying, an electrochemical sensor is obtained, namely a glassy carbon electrode modified with carbon nanotube / copper oxide / cuprous oxide nanocomposite.

[0041] Example 2

[0042] The glassy carbon electrode modified with the carbon nanotube / copper oxide / cuprous oxide nanocomposite prepared in Example 1 was used as the sensing interface. Using an electrolyte with a pH of 7.4, the oxidation peak current intensity of the creatinine-copper ion complex was measured at different creatinine concentrations. The linear relationship between the oxidation peak current and the corresponding creatinine concentration was fitted. The linear concentration range of creatinine was 0.01 mM to 1 mM, and the detection limit was 0.002 mM.

[0043] The glassy carbon electrode modified with the carbon nanotube / copper oxide / cuprous oxide nanocomposite prepared in Example 1 was used as the sensing interface. Using an electrolyte with a pH of 7.4, the oxidation peak current intensity of the uric acid-copper ion complex was measured at different uric acid concentrations. The linear relationship between the oxidation peak current and the corresponding uric acid concentration was fitted. The linear concentration range of uric acid was 0.001 mM to 5 mM, and the detection limit was 0.0004 mM.

[0044] A glassy carbon electrode modified with the carbon nanotube / copper oxide / cuprous oxide nanocomposite prepared in Example 1 was used as the sensing interface. An electrolyte with a pH of 7.4 was used to simultaneously measure the oxidation peak current intensities of the uric acid-copper ion complex and the creatinine-copper ion complex at different uric acid and creatinine concentrations. A linear relationship between the oxidation peak current and the corresponding uric acid and creatinine concentrations was fitted, with a linear concentration range of 0.01 mM to 2 mM and a detection limit of 0.01 mM. The highest sensitivity was observed for uric acid at 1148.14 μA / (mM·cm). 2 The highest creatinine sensitivity was 158.43 μA / (mM·cm). 2 ).

[0045] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A method for preparing an electrochemical sensor for simultaneous detection of creatinine and uric acid, characterized in that, The preparation method includes the following steps: S1: Ethanol, ethylene glycol and deionized water are mixed evenly to obtain the first mixed solution; S2: The carbon nanotubes and anhydrous copper acetate are uniformly mixed with the first mixed solution to obtain the second mixed solution; S3: Perform a hydrothermal reaction on the second mixed solution. After the reaction is completed and the solution is cooled, purify the solution to obtain the carbon nanotube / copper oxide / cuprous oxide nanocomposite. S4: Disperse the carbon nanotube / copper oxide / cuprous oxide nanocomposite in deionized water and mix it evenly to obtain a suspension; S5: The suspension is drop-coated onto the surface of the glassy carbon electrode and dried at room temperature; S6: Nafion solution is drop-coated onto the dried glassy carbon electrode surface, and the electrochemical sensor is obtained after drying.

2. The method for preparing an electrochemical sensor for simultaneous detection of creatinine and uric acid according to claim 1, characterized in that, The volume fraction ratio of ethanol, ethylene glycol and deionized water in step S1 is 2:5:

3.

3. The method for preparing an electrochemical sensor for simultaneously detecting creatinine and uric acid according to claim 1, characterized in that, The mass concentration ratio of carbon nanotubes and anhydrous copper acetate in step S2 is 1:3-15.

4. The method for preparing an electrochemical sensor for simultaneous detection of creatinine and uric acid according to claim 2, characterized in that, The mass concentration ratio of carbon nanotubes and anhydrous copper acetate in step S2 is 1:

7.

5. The method for preparing an electrochemical sensor for simultaneous detection of creatinine and uric acid according to claim 1, characterized in that, The hydrothermal reaction temperature in step S3 is 100-150℃, and the hydrothermal reaction time is 4-12h.

6. A method for preparing an electrochemical sensor for simultaneous detection of creatinine and uric acid according to claim 5, characterized in that, The hydrothermal reaction temperature in step S3 is 120°C, and the hydrothermal reaction time is 8 hours.

7. The method for preparing an electrochemical sensor for simultaneous detection of creatinine and uric acid according to claim 1, characterized in that, The specific purification steps in step S3 are as follows: after cooling, the product is centrifuged with deionized water and ethanol, washed, and then dried.

8. The method for preparing an electrochemical sensor for simultaneous detection of creatinine and uric acid according to claim 1, characterized in that, In step S4, the concentration of the carbon nanotube / copper oxide / cuprous oxide nanocomposite in the suspension in deionized water is 1 mg / ml, and in step S5, the amount of suspension dropped onto the glassy carbon electrode surface is 10 μL.

9. A method for preparing an electrochemical sensor for simultaneous detection of creatinine and uric acid according to claim 1, characterized in that, In step S6, the amount of Nafion solution dropped onto the glassy carbon electrode surface is 5 μL, and the concentration is 0.5 wt%.

10. An electrochemical sensor for simultaneous detection of creatinine and uric acid prepared by the preparation method according to any one of claims 1-9.

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