CN113125533B

CN113125533B - Method for detecting glucose

Info

Publication number: CN113125533B
Application number: CN201911404684.0A
Authority: CN
Inventors: 孙晶; 孟维琛; 刘泽平; 司夏晴; 郎明非
Original assignee: Dalian University
Current assignee: Dalian University
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2022-07-05
Anticipated expiration: 2039-12-31
Also published as: CN113125533A

Abstract

The present invention relates to a method for glucose detection. The invention uses a three-electrode system, takes a Ni-Cu alloy modified electrode as a working electrode, a Pt wire as a counter electrode and an Ag/AgCl electrode as a reference electrode, and a noble metal alloy modified electrode can be used as an anode in a fuel cell to carry out catalytic oxidation on glucose so as to realize glucose detection. The electrode is modified by the nano noble metal, and the noble metal has good catalytic effect and the microstructure of the electrode is a flower-shaped nano multidimensional structure, so that the electrode has strong anti-poisoning capability and stable structure. The electrochemical analysis method has the advantages of simple operation, short detection time, high accuracy and sensitivity, and can be widely applied to the measurement of practical samples.

Description

Method for detecting glucose

Technical Field

The invention relates to the technical field of electrochemical analysis, in particular to a novel method for determining glucose.

Background

Glucose is an organic compound, a monosaccharide of the greatest importance in the broadest distribution in nature, and is a polyhydroxyaldehyde. Glucose is readily absorbed into the blood and is therefore often used by hospital personnel, sports enthusiasts and by people in general as a powerful rapid energy supplement. Glucose can enhance memory, stimulate calcium absorption and increase intercellular channels. However, too much glucose intake can lead to obesity and diabetes. At present, the prevalence rate of diabetes is increasing, and diabetes has become a global problem. Therefore, the glucose detection means is increasing. At present, although the chromatographic analysis and the spectral analysis for glucose detection have high sensitivity and good specificity, the instrument is huge, needs to be operated by professional personnel and is not suitable for daily detection; the electrochemical detection method is becoming a research hotspot of people because of the characteristics of miniaturization of equipment, simple operation, high detection speed and the like.

Disclosure of Invention

In order to make up for the deficiencies of the prior art, the present invention provides a method for glucose detection. The invention has the following inventive concept: the Cu-Ni-carbon cloth nano alloy modified electrode is prepared by taking carbon cloth conduction as a substrate and depositing nano copper and nano nickel particles by an electrochemical method. On the basis, a new analysis method is provided for the determination of glucose.

In order to achieve the purpose, the invention adopts the technical scheme that:

the carbon cloth is used as a substrate, and after the carbon cloth is cleaned, metal is deposited on the surface of the carbon cloth by an electrochemical method. The deposited carbon cloth is used as a working electrode, a saturated calomel electrode is used as a reference electrode, a platinum wire is used as an auxiliary electrode to form a three-electrode system, and the three-electrode system is placed in the glucose solution to be detected and the supporting electrolyte; then, a cyclic voltammetry curve of glucose at a potential of-0.7 to 1V was recorded.

The specific operation steps comprise:

(1) a piece of carbon cloth to be used is taken, and is cut into a size of 10 multiplied by 20mm by a knife for standby. Rinsing with ultrapure water, ethanol and acetone for 15 minutes respectively. After repeating for 3 times, drying under flowing nitrogen gas for standby. An electrochemical workstation is utilized, a three-electrode system is adopted, cleaned carbon cloth is used as a working electrode, a saturated calomel electrode is used as a reference electrode, and a platinum wire electrode is placed into an electrolytic cell filled with nickel sulfate solution. Setting electrodeposition parameters of an electrochemical workstation by adopting a pulse potentiostatic method: the potential range is-0.9-0.6V, the pulse time is 1s, and the step number is 100. And immediately taking out the electrode after deposition, washing with deionized water for multiple times, blow-drying, depositing copper by adopting constant current, depositing for 400s under the current of 0.3mA, and washing and blow-drying. And (4) carrying out nitrogen protection on the modified electrode, and standing for three days for later use.

(2) Determination of glucose peak potential: and scanning in a potential range of 0-1V by using a cyclic voltammetry method, and recording the peak potential of glucose.

Further, the nickel sulfate solution is NiSO with the concentration of 0.02M₄And 0.1M Na₂SO₄The solution was mixed.

Further, the supporting electrolyte is a 0.1mol/LKOH solution with pH 14.

The electrode is modified by the nano noble metal, and the noble metal has good catalytic effect and the microstructure of the electrode is a flower-shaped nano multidimensional structure, so that the electrode has strong anti-poisoning capability and stable structure. The electrochemical analysis method has the advantages of simple operation, short detection time, high accuracy and sensitivity, and can be widely applied to the measurement of practical samples.

Drawings

FIG. 1 is a surface topography of a Cu-Ni-carbon cloth based nanoalloy modified electrode;

FIG. 2 is a pictorial view of a three electrode system;

FIG. 3 is a comparison of cyclic voltammograms of a glucose solution and a blank solution;

FIG. 4 shows the results of the response of different electrodes to glucose;

FIG. 5 is a graph of precision cyclic voltammograms of the measurement of electrodes.

Detailed Description

The technical solutions of the present invention are further described below with reference to the drawings and the specific embodiments, but the present invention is not limited to the embodiments in any way. In the examples, unless otherwise specified, the experimental methods are all conventional methods; unless otherwise indicated, the experimental reagents and materials were commercially available.

The preparation method of the Cu-Ni-carbon cloth nano alloy modified electrode in the following embodiment comprises the following steps:

(1) taking a piece of carbon cloth to be used, and cutting the carbon cloth with the size of 10 multiplied by 20mm by a knife for later use.

(2) Ultrasonically cleaning the carbon cloth for 15 minutes by using ultrapure water, then ultrasonically cleaning the carbon cloth for 15 minutes by using acetone and ethanol in sequence, and repeating the steps for 3 times. And drying the treated mixture, and protecting the treated mixture with nitrogen for later use.

(3) Preparing a Cu-Ni-carbon cloth composite electrode: using a three-electrode system, using a carbon cloth as a working electrode, and immersing the carbon cloth into 0.5M H₂SO₄And nickel sulfate, a platinum electrode was used as a counter electrode and Ag/AgCl as a reference electrode. Setting electrodeposition parameters of an electrochemical workstation by adopting a pulse potentiostatic method: the potential range is-0.9-0.6V, the pulse time is 1s, and the step number is 100. And immediately taking out the electrode after deposition, washing with deionized water for multiple times, blow-drying, depositing copper by adopting constant current, depositing for 400s under the current of 0.3mA, and washing and blow-drying. And (4) carrying out nitrogen protection on the modified electrode, and standing for three days for later use.

Example 1 comparison of Cyclic voltammograms of glucose solution and blank solution

Firstly, a Cu-Ni-carbon cloth composite electrode is used as a working electrode, a platinum electrode is used as a counter electrode, and Ag/AgCl is used as a reference electrode. Placing the three-electrode system in a 0.1mol/LKOH buffer solution, scanning within a potential range of-0.7-1V by using a cyclic voltammetry method, and recording a cyclic voltammetry curve of a blank solution; then, the three-electrode system is placed in 10mmol/L glucose solution to be detected containing 0.1mol/LKOH solution as supporting electrolyte, scanning is carried out in a potential range of-0.7-1V by using cyclic voltammetry, and a cyclic voltammetry curve of glucose is recorded. As shown in fig. 3. Two oxidation peaks of glucose appear around 0.6V. The high oxidation peak corresponds to the direct electrochemical oxidation of glucose, with the increase of the potential, the intermediate products generated by the oxidation of the glucose increase, occupy the active sites on the surface of the electrode, show that the current is reduced, the lower intermediate products represent the indirect electrochemical oxidation of the glucose, in the process of negative scanning, the intermediate products occupying the active sites on the surface of the electrode are reduced, the active sites are released, and then the secondary oxidation peak of the glucose is generated.

Example 2 response of different electrodes to glucose

Comparison of different electrodes. A Cu-Ni-carbon cloth electrode and a Ni-carbon cloth electrode are respectively used as working electrodes, a saturated calomel electrode is used as a reference electrode, a platinum wire electrode is used as a counter electrode, glucose solution to be detected with the concentration of 10mmol/L is placed in the counter electrode, and a cyclic voltammetry curve is recorded.

Firstly, a three-electrode system is placed in a glucose solution to be detected containing 0.1mol/LKOH solution as a supporting electrolyte, a cyclic voltammetry method is utilized to scan within a potential range of-0.7-1V, and a cyclic voltammetry curve of glucose is recorded. And then, changing the working electrode, scanning within a potential range of-0.7-1V by using a Ni-carbon cloth electrode as the working electrode through cyclic voltammetry, and recording a cyclic voltammetry curve. As shown in fig. 4. The oxidation peak current of the Cu-Ni-carbon cloth electrode is obviously higher than that of the Ni-carbon cloth electrode, which shows that the surface active area of the electrode is increased by depositing copper by taking the nickel nano particles as the substrate, so that the peak current is increased.

Example 3 response of different electrodes to glucose

Firstly, a three-electrode system is placed in a glucose solution to be detected containing 0.1mol/L KOH solution as supporting electrolyte, scanning is carried out within a potential range of-0.7-1V by using cyclic voltammetry, and the cyclic voltammetry curve of lactose is recorded by 5 times of scanning of the same electrode. As shown in fig. 4, the substantially overlapped curves were obtained, indicating that the precision of the electrode was high.

The above description is only for the purpose of creating a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can substitute or change the technical solution and the inventive concept of the present invention within the technical scope of the present invention.

Claims

1. A method for glucose testing, comprising the steps of:

the carbon cloth is adopted as a substrate, after the carbon cloth is cleaned, metal nano copper and nano nickel particles are deposited on the surface of the carbon cloth by an electrochemical method, and the Cu-Ni-carbon cloth nano alloy modified electrode is prepared, wherein the deposition step is as follows: the cleaned carbon cloth is taken as a working electrode, a saturated calomel electrode is taken as a reference electrode, a platinum wire electrode is taken as a counter electrode, and the counter electrode is put into an electrolytic cell filled with nickel sulfate solution; setting electrodeposition parameters of an electrochemical workstation by adopting a pulse potentiostatic method: the potential range is-0.9-0.6V, the pulse time is 1s, and the step number is 100; taking out the electrode immediately after deposition, washing with deionized water for multiple times, blow-drying, depositing copper by adopting constant current, depositing for 400s under the current of 0.3mA, washing and blow-drying; the modified electrode is protected by nitrogen and is placed for standby after three days;

the deposited Cu-Ni-carbon cloth nano alloy is used as a working electrode, a saturated calomel electrode is used as a reference electrode, a platinum wire is used as an auxiliary electrode to form a three-electrode system, and the three-electrode system is placed in glucose solution to be detected and supporting electrolyte; then, a cyclic voltammetry curve of glucose at a potential of-0.7 to 1V was recorded.