CN105004781A - Dopamine detecting method based on paper-base electrochemistry device - Google Patents

Abstract

The invention discloses a method for measuring dopamine based on a paper-based electrochemical device. A circular hydrophilic area surrounded by a hydrophobic area; (2) differential pulse voltammetry to measure dopamine, making a working curve for measuring dopamine, and the detection platform can sensitively measure dopamine in the presence of interfering substances; adding the sample to be tested to the detection platform can The detection of dopamine in real samples was carried out. The invention provides a method for measuring dopamine based on a paper-based electrochemical device. The paper-based electrochemical analysis system is a new electrochemical device, which is simple to manufacture and low in cost, and can be used in many application fields, including portable , Disposable analytical equipment, food quality control and environmental monitoring, etc.

Description

A method for measuring dopamine based on a paper-based electrochemical device

technical field

The invention relates to the field of biotechnology detection, in particular to a method for measuring dopamine based on a paper-based electrochemical device.

Background technique

Dopamine (DA), chemically known as 4-(2-ethylamino)benzene-1,2-diol, is a key neurotransmitter in the hypothalamus and pituitary gland, widely found in vertebrates and invertebrates Moderate; lack of dopamine can make people feel sluggish and light-headed. Excessive dopamine will have the opposite problem, such as causing people to be irritable, unable to control emotions, and speed up nerve reflexes. The case is characterized by extreme hyperactivity, and long-term massive electrical pulse stimulation will cause irreversible damage to the nerves. Abnormal levels of dopamine can lead to many diseases such as Parkinson's syndrome and schizophrenia. Therefore, the detection of dopamine is of great significance for rapid clinical diagnosis of related diseases, neurophysiological research and quality control of related drugs. Commonly used methods for detecting dopamine include high-performance liquid chromatography fluorescence detection method, capillary electrophoresis method, chemiluminescence method, etc. These traditional methods have the advantages of accurate determination and good selectivity. However, these methods generally have the disadvantages of expensive instruments, high operating costs, and not easy to carry, and are greatly limited in continuous monitoring and on-site measurement, and cannot meet the requirements of fast, multi-sample, simple, and real-time analysis in sample analysis. . Therefore, designing a simple, accurate, fast, sensitive and easy-to-operate detection method for dopamine has aroused the interest of many researchers.

Contents of the invention

The object of the present invention is to provide a method for measuring dopamine based on a paper-based electrochemical device, which can solve one or more of the above-mentioned problems in the prior art.

According to one aspect of the present invention, a kind of method for measuring dopamine based on paper-based electrochemical device comprises the steps:

(1) Filter paper is used as the detection platform of the paper-based substrate, the electrodes are manually drawn with a pencil, and graphite is used as the electrode material. There is a circular hydrophilic area in the middle of the detection platform, surrounded by hydrophobic areas;

(2) Determination of dopamine by differential pulse voltammetry, making a working curve for the determination of dopamine, the detection platform can sensitively measure dopamine in the presence of interfering substances; adding the sample to be tested to the detection platform for the detection of dopamine in the actual sample.

The present invention provides a method for measuring dopamine based on a paper-based electrochemical device. The paper-based electrochemical analysis system is a new electrochemical device, which is simple to manufacture and low in cost, and can be used in many application fields, including clinical diagnosis. Portable, disposable analysis equipment, food quality control and environmental monitoring, etc.

In some embodiments, the manufacturing method of the detection platform and the electrode template of the paper-based substrate in step (1) is as follows,

(1) Use Photoshop software to draw, the graphic style is: a square with a side length of 19.5mm, a circle with a diameter of 6.5mm in the middle of the square, the circular area is white, and the rest is black;

(2) Print the drawn graphic template on the filter paper, then place the filter paper in an oven, the temperature of the oven is set at 150 degrees Celsius, and the time is 3 hours; its purpose is to penetrate the wax in the black area into the middle layer of the filter paper to form The hydrophobic area, the white part of the filter paper is the hydrophilic area; then the filter paper is dried and the template is cut out.

(3) With 6B pencil as the electrode material, a three-electrode system is drawn on the detection platform of the prepared paper-based substrate. The size requirements of the three electrodes are: the width of the working electrode is 3mm, and the length is 6mm. The length is 2mm, the width of the counter electrode and the reference electrode is 2mm, the length is 6mm, and the length in the hydrophilic region is 2mm.

In some embodiments, the detection platform of the designed paper-based substrate is connected to the CHI1230B electrochemical workstation, and then the dopamine standard with a concentration of 0.1, 0.5, 1, 5, 10, 50, 100, 400, 700 micromoles per liter is prepared solution, pH = 7.4 phosphate buffer as the electrolyte solution; 10 microliters of dopamine standard solution was added dropwise to the middle hydrophilic region of the electrode, and a differential pulse voltammetry scan was performed in the potential range of -0.2 to 0.6V to obtain 0.1 , 0.5, 1, 5, 10, 50, 100, 400, 700 micromoles per liter concentration of the dopamine solution scanning curve, according to the concentration of the standard solution and its corresponding peak current value, the linear relationship between the two can be calculated to obtain Working curve; when detecting dopamine in urine or blood samples, the concentration of dopamine in the sample can be calculated according to the current value of the detection curve.

Graphite is a very good conductive material, and its price is lower than some other conventional conductive materials, and its stability is better than some other conventional electrode materials. Therefore, the combination of graphite and paper to construct a disposable paper-based electrochemical analysis device has the advantages of low cost and portability; and the highly developed infrastructure printing industry makes the production economy of this paper-based analysis device developable; Using paper as the research substrate, a three-electrode system is constructed by drawing pencil electrodes by hand, and a complete electrochemical analysis and detection device is made. This graphite paper-based electrochemical system is simple to manufacture, cheap, easy to operate, and has good stability.

Graphite paper-based electrochemical devices have the following unique advantages: 1. Both paper and graphite are relatively cheap and easy to obtain. 2. The filter paper with a porous structure is mainly composed of cellulose, which can support the electrolyte, and the required sample volume is only a few microliters. 3. Paper is a good filter. 4. Graphite electrodes have relatively stable electrochemical properties.

As a disposable electrode, it can provide a clean surface for each measurement. In addition, the low-cost graphite electrode avoids expensive instruments and maintenance costs. At the same time, it is easy to manufacture and can be mass-produced.

The paper-based electrochemical sensing device constructed by the present invention not only avoids the interference of ascorbic acid and uric acid on the determination of dopamine, but also improves the sensitivity and reproducibility of detection. Compared with the existing electrochemical sensors, the present invention has a linear range Wide, low detection limit, simple production, low cost, rapid and convenient analysis and detection, and can be used for clinical analysis.

Electrochemical methods have attracted great attention due to their traditional advantages in high sensitivity, short measurement cycle, and high reliability, and have been widely used in the analysis and detection of neurotransmitters. Electroanalytical methods often use electrodeposition as a pre-concentration method. Pre-concentration or enrichment before determination will greatly improve the sensitivity and selectivity of the analysis, making it more suitable for the determination of trace substances. Compared with other detection methods, the electrochemical method has simple equipment, is easy to carry, and is easy to operate. It can quickly detect multiple substances at the same time, and is easy to realize on-site automatic detection. It has been widely promoted in modern sanitation analysis.

In the development of analytical chemistry, the study of patterned filter paper provides a broader idea for the development of portable analytical instruments. Filter paper has the characteristics of good absorption, softness and easy operation, portability, and low cost. It is an ideal material for building an analysis system. The paper is mainly composed of cellulose, which is porous and hydrophilic. It contains a large amount of Hydrophilic groups such as carboxyl and hydroxyl groups can absorb water much larger than its own weight. In addition, paper also has the advantages of low cost, light weight, and portability. Compared with substrates such as polymers and glass, its biggest advantage is that it can be biodegraded after use and is harmless to the environment. Graphite is a very good conductive material, and its price is lower than some other conventional conductive materials, and its stability is better than some other conventional electrode materials. Therefore, the combination of graphite and paper to construct a disposable graphite paper-based electrode detection and analysis device has the advantages of low cost and portability.

Differential pulse voltammetry is an electrochemical measurement method, which is a derivative method of linear sweep voltammetry and ladder sweep voltammetry, that is, a certain voltage pulse is added on the basis of it. The effect of the charging current is reduced by measuring the current before the potential change.

Description of drawings

FIG. 1 is an electrode model diagram of a graphite paper-based substrate of a method for measuring dopamine based on a paper-based electrochemical device of the present invention.

Detailed ways

A method for measuring dopamine based on a paper-based electrochemical device, comprising the steps of:

(1) Filter paper is used as the detection platform of the paper-based substrate, the electrodes are manually drawn with a pencil, and graphite is used as the electrode material. There is a circular hydrophilic region in the middle of the detection platform, surrounded by hydrophobic regions.

(2) Determination of dopamine by differential pulse voltammetry, making a working curve for the determination of dopamine, the detection platform can sensitively measure dopamine in the presence of interfering substances; adding the sample to be tested to the detection platform for the detection of dopamine in the actual sample.

As shown in Figure 1, the detection platform of the paper-based substrate in step (1) and the preparation method of the electrode template are as follows,

(1) Use Photoshop software to draw, the graphic style is: a square with a side length of 19.5mm, a circle with a diameter of 6.5mm in the middle of the square, the circular area is white, and the rest is black;

(2) Print the drawn graphic template on the filter paper, then place the filter paper in an oven, the temperature of the oven is set at 150 degrees Celsius, and the time is 3 hours; its purpose is to penetrate the wax in the black area into the middle layer of the filter paper to form The hydrophobic area, the white part of the filter paper is the hydrophilic area; then the filter paper is dried and the template is cut out.

(3) With 6B pencil as the electrode material, a three-electrode system is drawn on the detection platform of the prepared paper-based substrate. The size requirements of the three electrodes are: the width of the working electrode is 3mm, and the length is 6mm. The length is 2mm, the width of the counter electrode and the reference electrode is 2mm, the length is 6mm, and the length in the hydrophilic region is 2mm.

In some embodiments, the detection platform of the designed paper-based substrate is connected to the CHI1230B electrochemical workstation, and then the dopamine standard with a concentration of 0.1, 0.5, 1, 5, 10, 50, 100, 400, 700 micromoles per liter is prepared solution, pH = 7.4 phosphate buffer as the electrolyte solution; 10 microliters of dopamine standard solution was added dropwise to the middle hydrophilic region of the electrode, and a differential pulse voltammetry scan was performed in the potential range of -0.2 to 0.6V to obtain 0.1 , 0.5, 1, 5, 10, 50, 100, 400, 700 micromoles per liter concentration of the dopamine solution scanning curve, according to the concentration of the standard solution and its corresponding peak current value, the linear relationship between the two can be calculated to obtain Working curve; when detecting dopamine in urine or blood samples, the concentration of dopamine in the sample can be calculated according to the current value of the detection curve.

Graphite is a very good conductive material, and its price is lower than some other conventional conductive materials, and its stability is better than some other conventional electrode materials. Therefore, the combination of graphite and paper to construct a disposable paper-based electrochemical analysis device has the advantages of low cost and portability; and the highly developed infrastructure printing industry makes the production economy of this paper-based analysis device developable; Using paper as the research substrate, a three-electrode system is constructed by drawing pencil electrodes by hand, and a complete electrochemical analysis and detection device is made. This graphite paper-based electrochemical system is simple to manufacture, cheap, easy to operate, and has good stability.

Graphite paper-based electrochemical devices have the following unique advantages: 1. Both paper and graphite are relatively cheap and easy to obtain. 2. The filter paper with a porous structure is mainly composed of cellulose, which can support the electrolyte, and the required sample volume is only a few microliters. 3. Paper is a good filter. 4. Graphite electrodes have relatively stable electrochemical properties.

As a disposable electrode, it can provide a clean surface for each measurement. In addition, the low-cost graphite electrode avoids expensive instruments and maintenance costs. At the same time, it is easy to manufacture and can be mass-produced.

The paper-based electrochemical sensing device constructed by the present invention not only avoids the interference of ascorbic acid and uric acid on the determination of dopamine, but also improves the sensitivity and reproducibility of detection. Compared with the existing electrochemical sensors, the present invention has a linear range Wide, low detection limit, simple production, low cost, rapid and convenient analysis and detection, and can be used for clinical analysis.

The present invention provides a method for measuring dopamine based on a paper-based electrochemical device. The paper-based electrochemical analysis system is a new electrochemical device, which is simple to manufacture and low in cost, and can be used in many application fields, including clinical diagnosis. Portable, disposable analysis equipment, food quality control and environmental monitoring, etc.

The above description is only the preferred mode of the present invention. It should be pointed out that those skilled in the art can make several similar deformations and improvements without departing from the inventive concept of the present invention, and these should also be regarded as within the protection scope of the present invention.

Claims (3)

1., based on a method for the mensuration dopamine of paper substrate electrochemical appliance, it is characterized in that being, comprise the steps:

(1) detection platform using filter paper as paper substrate substrate, pencil manual drawing electrode, using graphite as electrode material, having circular hydrophilic region in the middle of detection platform, is around hydrophobic region;

(2) Differential Pulse Voltammetry measures dopamine, makes and measures the working curve of dopamine, detection platform can under chaff interference exists sensitive determination dopamine; Testing sample is added the detection that detection platform carries out dopamine in actual sample.

2. the method for a kind of mensuration dopamine based on paper substrate electrochemical appliance according to claim 1, is characterized in that being, the detection platform of the paper substrate substrate in described step (1) and the method for making of electrode template as follows,

(1) utilize Photoshop software by drawing, the pattern of figure is: the length of side is the square of 19.5mm, the circle of in the middle of square to be diameter be 6.5mm, and border circular areas be white, and remainder is black;

(2) be printed on filter paper by drawn graphics template, then filter paper be placed in baking oven, the temperature of baking oven is set to 150 degrees Celsius, and the time is 3 hours; Its objective is and the wax of black region is penetrated into filter paper middle layer, form hydrophobic region, filter paper white portion is hydrophilic area; Then filter paper is dried, template is cut.

(3) with 6B pencil for electrode material, the detection platform of the paper substrate substrate made draws out three-electrode system, three electrode dimensional requirement is: the wide of working electrode is 3mm, long is 6mm, length in hydrophilic area is 2mm, be 2mm to electrode and the wide of contrast electrode, long is 6mm, and the length in hydrophilic area is 2mm (as Fig. 1).

3. the method for a kind of mensuration dopamine based on paper substrate electrochemical appliance according to claim 2, it is characterized in that, the detection platform of the paper substrate substrate designed is connected with CHI1230B electrochemical workstation, then prepare the dopamine standard solution that 0.1,0.5,1,5,10,50,100,400,700 micromoles often rise concentration, the phosphate buffer of pH=7.4 is as electrolyte solution; Get the midparent aqua region that 10 microlitre dopamine standard solution are added drop-wise to electrode, differential pulse voltammetry voltammetric scan is made in the potential range of-0.2 ~ 0.6V, obtain the scanning curve that 0.1,0.5,1,5,10,50,100,400,700 micromoles often rise the dopamine solution of concentration, the peak point current corresponding with it according to the concentration of standard solution, the linear relationship of the two can be calculated, obtain working curve; When detecting the dopamine in testing sample urine sample or blood sample, the concentration of dopamine in sample can be obtained according to the current value of detection curve.