CN109709182B - Based on g-C3N4-MnO2Method for ultrasensitive detection of glutathione by photo-electrochemical method of nano composite material - Google Patents

Abstract

The invention discloses a g-C₃N₄‑MnO₂The photo-induced electrochemical method of the nano composite material detects the glutathione with ultra sensitivity. By growing g-C on paper substrate₃N₄‑MnO₂Nanocomposite, preparation of g-C₃N₄‑MnO₂GSH sensor, using MnO₂Specific selection for GSH and g-C₃N₄‑MnO₂Nanocomposite and g-C₃N₄‑MnO₂The sensitive photocurrent response of the GSH sensor, enabling ultrasensitive detection of GSH. Compared with other traditional methods, the sensing system effectively reduces the detection limit of GSH, and has the advantages of simple operation and high detection efficiency.

Description

Based on g-C3N4-MnO2Method for ultrasensitive detection of glutathione by photo-electrochemical method of nano composite material

Technical Field

The invention relates to the technical field of glutathione detection, in particular to a method based on g-C₃N₄-MnO₂A method for ultrasensitive detection of Glutathione (GSH) by a photo-electrochemical method of a nano composite material.

Background

Electrochemiluminescence (ECL) is an intermediate method between electrochemistry and chemiluminescence, and has become an important powerful analytical method in analytical and clinical medicine due to its characteristics of simplicity, easy operation, low cost and high sensitivity. More importantly, ECL is superior to other analytical methods because it does not require a light source and results are presented in a simple meter, low background or zero background signal.

The nano composite material is a material with new performance formed by two or more than two materials with different properties through physical or chemical methods on a macroscopic scale. The materials mutually make up for the deficiencies in performance to generate a synergistic effect, so that the comprehensive performance of the composite material is superior to the performance of the original materials, thereby meeting various different requirements.

Glutathione is a tripeptide (L- γ -glutamyl-L-cysteinyl-glycine) compound that is widely distributed in animals, plants, grains and oilseeds and has one of its functions in cells to protect against various toxins and carcinogens, and studies have shown that: glutathione is completely absorbed in the small intestine and some epithelial cells are detoxified by exogenous glutathione, indicating that dietary glutathione determines the degree of cellular damage in humans. Besides being used as an antitoxic, the glutathione also has an activation effect on certain sulfhydryl enzymes, can be used as an antioxidant for protecting enzymes and other protein sulfydryl, and plays a certain role in the processes of biological oxidation, amino acid transport, hemoglobin protection and the like. In addition, recently, glutathione has been found to have an HIV inhibitory effect. Therefore, the research on the glutathione has important significance on the health and life of human beings.

Disclosure of Invention

The invention aims to solve the technical problem of providing a photo-induced electrochemical analysis detection method with high sensitivity and strong specificity, which can be easily realized in most laboratories without complex and fussy large-scale equipment support. The specific preparation scheme is as follows:

(1) preparing a flower-shaped gold nanoparticle paper chip: designing a hydrophobic wax batch printing pattern of the microfluidic paper chip on a computer by using Adobe Illustrator CS4 software, wherein the pattern is shown in figure 1, the microfluidic paper chip comprises a hydrophobic area printed by external wax and an internal hydrophilic working area, the size of a single unit is 30 x 30mm, the diameter of the hydrophilic area is 10mm, the size of a channel is 6.5 x 8mm, and the used paper chip is chromatographic paper; measuring 80mL of ultrapure water, heating to 90 ℃, adding 0.8mL of chloroauric acid solution with the mass fraction of 1%, continuously heating to 96 ℃, keeping the temperature for 1min, adding 2.8mL of sodium citrate with the mass fraction of 1%, keeping the temperature for 8min at 96 ℃ to obtain a gold seed solution, measuring 20 mu L of the obtained gold seed solution, dropwise adding the gold seed solution into a working area, standing, airing, and repeating for three times; respectively measuring 100 mu L of 200mmol/L ascorbic acid solution and 100 mu L of chloroauric acid solution with the mass fraction of 1% at room temperature, measuring 20 mu L mixed solution, dropwise adding the mixed solution into a working area modified with gold seeds, standing for 30min, and washing for 3 times by using ultrapure water to obtain a flower-shaped gold nanoparticle paper chip;

(2) preparation of g-C₃N₄-MnO₂And (3) carrying out photoelectric detection on the nano composite material: measuring 250 mu L g-C₃N₄Adding the nanosheet solution into 2.5mL of 0.1M pH 6.0 2- (N-morpholino) ethanesulfonic acid buffer solution to obtain a mixed solution, measuring 1mL of 10mM KMnO₄Adding 10ml ultrapure water into the mixed solution, performing ultrasonic treatment for 30min to form brown colloid, centrifuging, and collecting g-C₃N₄-MnO₂Washing the nano composite material with ultrapure water for 3 times, and dispersing a product obtained by centrifugation into 10mL of ultrapure water; measuring 20 μ L of the above solution, dripping onto the surface of the obtained paper chip working area containing flower-like gold nanoparticles, standing for 30min, and rinsing with ultrapure water for 3 times; will contain g-C₃N₄-MnO₂Connecting a paper chip of the nano composite material with a working electrode, placing the paper chip in a PBS (phosphate buffer solution) solution with the pH value of 7.4, and collecting a generated photocurrent signal by using a three-electrode system;

(3) preparation of g-C₃N₄-MnO₂GSH sensor and photoelectric detection: 10. mu.L of g-C was measured₃N₄-MnO₂Mixing the nano-composite solution and 10 mu L of GSH in a 1.5mL centrifuge tube, incubating for 7min, measuring a proper amount of ultrapure water, diluting the mixed solution to 250 mu L, and fully mixing; measuring 20 mu L of the solution, dropwise adding the solution to the surface of the working area of the paper chip containing the flower-shaped gold nanoparticles obtained in the step (2), standing for 30min, and washing for 3 times by using ultrapure water; will contain g-C₃N₄-MnO₂-the GSH sensor is connected to a working electrode, placed in a PBS solution at pH 7.4, and the optoelectronic signal is collected using a three-electrode system;

(4) photoelectric signal analysis: and analyzing and calculating the content of the GSH in the solution to be detected by combining the photoelectric signals obtained in the steps. The invention has the beneficial effects that:

(1) the method has the advantages of low cost, simple experimental operation and easily controlled reaction conditions;

(2) compared with the traditional glassy carbon electrode and glass electrode, the paper substrate has rich raw materials, light weight, low price, easy folding and degradability;

(3) the paper-based sensor is flexible and convenient to carry, can be cut, bent, folded and plastic, has simple post-treatment and does not pollute the environment;

(4) the paper is usually white and the background signal is low.

Drawings

FIG. 1 is a paper chip layout of the present invention.

Detailed Description

The following is a description of detailed embodiments of the present invention: based on g-C₃N₄-MnO₂A method for detecting glutathione with ultrasensitiveness by a photo-electrochemical method of a nano composite material.

Example 1 (detection of GSH in aqueous solution)

(1) Preparing a flower-shaped gold nanoparticle paper chip: designing a hydrophobic wax batch printing pattern of the microfluidic paper chip on a computer by using Adobe Illustrator CS4 software, wherein the pattern is shown in figure 1, the microfluidic paper chip comprises a hydrophobic area printed by external wax and an internal hydrophilic working area, the size of a single unit is 30 x 30mm, the diameter of the hydrophilic area is 10mm, the size of a channel is 6.5 x 8mm, and the used paper chip is chromatographic paper; measuring 80mL of ultrapure water, heating to 90 ℃, adding 0.8mL of chloroauric acid solution with the mass fraction of 1%, continuously heating to 96 ℃, keeping the temperature for 1min, adding 2.8mL of sodium citrate with the mass fraction of 1%, keeping the temperature for 8min at 96 ℃ to obtain a gold seed solution, measuring 20 mu L of the obtained gold seed solution, dropwise adding the gold seed solution into a working area, standing, airing, and repeating for three times; respectively measuring 100 mu L of 200mmol/L ascorbic acid solution and 100 mu L of chloroauric acid solution with the mass fraction of 1% at room temperature, measuring 20 mu L mixed solution, dropwise adding the mixed solution into a working area modified with gold seeds, standing for 30min, and washing for 3 times by using ultrapure water to obtain a flower-shaped gold nanoparticle paper chip;

(2) preparation of g-C₃N₄-MnO₂And (3) carrying out photoelectric detection on the nano composite material: measuring 250μL g-C₃N₄Adding the nanosheet solution into 2.5mL of 0.1M pH 6.0 2- (N-morpholino) ethanesulfonic acid buffer solution to obtain a mixed solution, measuring 1mL of 10mM KMnO₄Adding 10ml ultrapure water into the mixed solution, performing ultrasonic treatment for 30min to form brown colloid, centrifuging, and collecting g-C₃N₄-MnO₂Washing the nano composite material with ultrapure water for 3 times, and dispersing a product obtained by centrifugation into 10mL of ultrapure water; measuring 20 μ L of the above solution, dripping onto the surface of the obtained paper chip working area containing flower-like gold nanoparticles, standing for 30min, and rinsing with ultrapure water for 3 times; will contain g-C₃N₄-MnO₂Connecting a paper chip of the nano composite material with a working electrode, placing the paper chip in a PBS (phosphate buffer solution) solution with the pH value of 7.4, and collecting a generated photocurrent signal by using a three-electrode system;

(3) preparation of g-C₃N₄-MnO₂GSH sensor and photoelectric detection: 10. mu.L of g-C was measured₃N₄-MnO₂Mixing the nano-composite solution and 10 mu L of GSH in a 1.5mL centrifuge tube, incubating for 7min, measuring a proper amount of ultrapure water, diluting the mixed solution to 250 mu L, and fully mixing; measuring 20 mu L of the solution, dropwise adding the solution to the surface of the working area of the paper chip containing the flower-shaped gold nanoparticles obtained in the step (2), standing for 30min, and washing for 3 times by using ultrapure water; will contain g-C₃N₄-MnO₂-the GSH sensor is connected to a working electrode, placed in a PBS solution at pH 7.4, and the optoelectronic signal is collected using a three-electrode system;

(4) photoelectric signal analysis: and analyzing and calculating the content of the GSH in the solution to be detected by combining the photoelectric signals obtained in the steps.

Claims (1)

1. Based on g-C₃N₄-MnO₂The method for ultrasensitively detecting Glutathione (GSH) by the photo-electrochemical method of the nano composite material is characterized by comprising the following steps of:

(1) preparing a flower-shaped gold nanoparticle paper chip: designing a hydrophobic wax batch printing pattern of a microfluidic paper chip on a computer by using Adobe Illustrator CS4 software, wherein the microfluidic paper chip comprises a hydrophobic area printed by external wax and an internal hydrophilic working area, the size of a single unit is 30 x 30mm, the diameter of the hydrophilic area is 10mm, the size of a channel is 6.5 x 8mm, and the used paper chip is chromatographic paper; measuring 80mL of ultrapure water, heating to 90 ℃, adding 0.8mL of chloroauric acid solution with the mass fraction of 1%, continuously heating to 96 ℃, keeping the temperature for 1min, adding 2.8mL of sodium citrate with the mass fraction of 1%, keeping the temperature for 8min at 96 ℃ to obtain a gold seed solution, measuring 20 mu L of the obtained gold seed solution, dropwise adding the gold seed solution into a working area, standing, airing, and repeating for three times; respectively measuring 100 mu L of 200mmol/L ascorbic acid solution and 100 mu L of chloroauric acid solution with the mass fraction of 1% at room temperature, mixing, measuring 20 mu L of the mixed solution, dropwise adding the mixed solution into a working area modified with gold seeds, standing for 30min, and washing for 3 times with ultrapure water to obtain a flower-shaped gold nanoparticle paper chip;

(2) preparation of g-C₃N₄-MnO₂And (3) carrying out photoelectric detection on the nano composite material: measuring 250 mu L g-C₃N₄Adding the nanosheet solution into 2.5mL of 0.1M pH 6.0 2- (N-morpholino) ethanesulfonic acid buffer solution to obtain a mixed solution, measuring 1mL of 10mM KMnO₄Adding 10ml ultrapure water into the mixed solution, performing ultrasonic treatment for 30min to form brown colloid, centrifuging, and collecting g-C₃N₄-MnO₂Washing the nano composite material with ultrapure water for 3 times, and dispersing a product obtained by centrifugation into 10mL of ultrapure water; measuring 20 μ L of the above solution, dripping onto the surface of the obtained paper chip working area containing flower-like gold nanoparticles, standing for 30min, and rinsing with ultrapure water for 3 times; will contain g-C₃N₄-MnO₂Connecting a paper chip of the nano composite material with a working electrode, placing the paper chip in a PBS (phosphate buffer solution) solution with the pH value of 7.4, and collecting a generated photocurrent signal by using a three-electrode system;

(3) preparation of g-C₃N₄-MnO₂GSH sensor and photoelectric detection: 10. mu.L of g-C was measured₃N₄-MnO₂Mixing the nano-composite solution and 10 mu L of GSH in a 1.5mL centrifuge tube, incubating for 7min, measuring a proper amount of ultrapure water, diluting the mixed solution to 250 mu L, and fully mixing; measuring 20 μ L of the above solution, and adding dropwise to the flower-containing solution obtained in step (2)Standing the surface of the paper chip working area of the gold-shaped nano particles for 30min, and washing the surface for 3 times by using ultrapure water; will contain g-C₃N₄-MnO₂-the GSH sensor is connected to a working electrode, placed in a PBS solution at pH 7.4, and the optoelectronic signal is collected using a three-electrode system;

(4) photoelectric signal analysis: and analyzing and calculating the content of the GSH in the solution to be detected by combining the photoelectric signals obtained in the steps.

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