CN113406171B - Composite electrode and preparation method and application thereof - Google Patents
Composite electrode and preparation method and application thereof Download PDFInfo
- Publication number
- CN113406171B CN113406171B CN202110583541.1A CN202110583541A CN113406171B CN 113406171 B CN113406171 B CN 113406171B CN 202110583541 A CN202110583541 A CN 202110583541A CN 113406171 B CN113406171 B CN 113406171B
- Authority
- CN
- China
- Prior art keywords
- composite electrode
- gold
- electrode
- polyaniline
- composite
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
- G01N27/28—Electrolytic cell components
- G01N27/30—Electrodes, e.g. test electrodes; Half-cells
- G01N27/327—Biochemical electrodes, e.g. electrical or mechanical details for in vitro measurements
- G01N27/3275—Sensing specific biomolecules, e.g. nucleic acid strands, based on an electrode surface reaction
- G01N27/3277—Sensing specific biomolecules, e.g. nucleic acid strands, based on an electrode surface reaction being a redox reaction, e.g. detection by cyclic voltammetry
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
- G01N27/28—Electrolytic cell components
- G01N27/30—Electrodes, e.g. test electrodes; Half-cells
- G01N27/308—Electrodes, e.g. test electrodes; Half-cells at least partially made of carbon
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
- G01N27/28—Electrolytic cell components
- G01N27/30—Electrodes, e.g. test electrodes; Half-cells
- G01N27/327—Biochemical electrodes, e.g. electrical or mechanical details for in vitro measurements
- G01N27/3275—Sensing specific biomolecules, e.g. nucleic acid strands, based on an electrode surface reaction
- G01N27/3278—Sensing specific biomolecules, e.g. nucleic acid strands, based on an electrode surface reaction involving nanosized elements, e.g. nanogaps or nanoparticles
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
- G01N27/28—Electrolytic cell components
- G01N27/30—Electrodes, e.g. test electrodes; Half-cells
- G01N27/38—Cleaning of electrodes
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Molecular Biology (AREA)
- Physics & Mathematics (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Nanotechnology (AREA)
- Engineering & Computer Science (AREA)
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
Abstract
The invention discloses a composite electrode and a preparation method and application thereof, and belongs to the technical field of electrochemical biosensors. A composite electrode, comprising: a conductive base; a polyaniline/graphene composite layer; the polyaniline/graphene composite layer is coated on the surface of the conductive matrix; gold-platinum bimetallic nanoparticles; the gold-platinum bimetallic nanoparticles are deposited on the surface of the polyaniline/graphene composite layer. The composite electrode provided by the invention improves the stability of the composite electrode and the detection sensitivity of hormone through the synergistic effect of all parts, and can simultaneously detect dopamine, 5-hydroxytryptamine and melatonin.
Description
Technical Field
The invention belongs to the technical field of electrochemical biosensors, and particularly relates to a composite electrode and a preparation method and application thereof.
Background
With the social development and the accelerated pace of life, the pressure of people in all aspects is getting larger, and in addition to the rapid development of mobile internet products, the sleep problem of people is getting more serious, and the people are developing towards the direction of youthfulness and generalization.
The level of neurotransmitters and hormones largely determines the quality of sleep, and the neurotransmitters and hormones involved in sleep are mainly dopamine, 5-hydroxytryptamine and melatonin. Poor sleep quality, and most likely an abnormality in the content of these three hormones, in particular:
dopamine (Dopamine), formula C 8 H 11 NO 2 The dopamine neurotransmitter is a catechol neurotransmitter, can regulate and control various physiological functions of a central nervous system, has an excitation function, can cause the problems of fatigue, somnolence, low emotion and the like due to the fact that the dopamine in a human body is excessively secreted, and can cause the symptoms of insomnia, easy emotion excitement and the like due to the fact that the dopamine is excessively secreted.
5-hydroxytryptamine (5-hydroxytryptamine) of formula C 10 H 12 N 2 O, also known as serotonin, is an inhibitory neurotransmitter, and the lack of 5-hydroxytryptamine in the body causes the problems of poor sleep, difficult sleep, easy waking, short sleep time and the like.
Melatonin (Melatonin), formula C 13 H 16 N 2 O 2 Also known as pineal hormone, is one of the hormones secreted by the pineal gland. Melatonin secretion has a clear circadian rhythm, is inhibited during the day and is active at night. Melatonin can improve sleep, shorten wake time before sleep and fall asleep time, and improve sleep quality.
Sleep is an indispensable life requirement, the quality of sleep is closely related to human health, the immunity is reduced due to long-term poor sleep quality, various diseases are caused, and the health is greatly damaged, so that a method for simultaneously detecting the three substances is necessary.
There are many methods for detecting hormones, such as high performance liquid chromatography, spectrophotometry, chemiluminescence, mass spectrometry, and near infrared spectroscopy, but these methods generally have the problems of low operation integration level, expensive and heavy instruments, inconvenient field detection, high economic cost of detection, high detection time/labor cost, etc. Compared with other detection methods, the electrochemical analysis method has the advantages of high sensitivity, high analysis speed, simple instrument and equipment, easy miniaturization and integration, and contribution to realizing field detection and online real-time monitoring.
However, oxidation potentials of dopamine, 5-hydroxytryptamine and melatonin are similar, and the oxidation potentials are difficult to distinguish on a common electrode, that is, the common electrode cannot detect dopamine, 5-hydroxytryptamine and melatonin at the same time.
Disclosure of Invention
The present invention is directed to solving at least one of the problems of the prior art described above. Therefore, the composite electrode provided by the invention has the advantages that the stability of the composite electrode is improved and the detection sensitivity to hormone is improved through the synergistic effect among the conductive matrix, the polyaniline/graphene composite layer and the gold-platinum bimetallic nanoparticles, the oxidation peaks of dopamine, 5-hydroxytryptamine and melatonin can be separated, and the separate detection or the simultaneous detection of the dopamine, 5-hydroxytryptamine and melatonin can be realized.
The invention also provides a preparation method of the composite electrode.
The invention also provides an application of the composite electrode in hormone detection.
The invention also provides a detection sensor comprising the composite electrode.
The invention also provides a detection system comprising the detection sensor.
According to an aspect of the present invention, there is provided a composite electrode comprising:
a conductive base;
a polyaniline/graphene composite layer; the polyaniline/graphene composite layer is coated on the surface of the conductive substrate;
gold-platinum bimetallic nanoparticles; the gold-platinum bimetallic nanoparticles are deposited on the surface of the polyaniline/graphene composite layer.
According to a preferred (specific) embodiment of the present invention, at least the following advantageous effects are obtained:
(1) In the polyaniline/graphene composite layer adopted by the invention, graphene and polyaniline both have special electrical properties, and after the polyaniline/graphene composite layer is modified to the surface of a conductive matrix, on one hand, the conductivity of the composite electrode can be increased, and on the other hand, the polyaniline/graphene composite layer can be used as an active substance, so that the detection sensitivity of the composite electrode on hormone is improved.
(2) In the gold-platinum bimetallic nano-particles adopted by the invention, gold and platinum respectively have catalytic activity, and after the gold and the platinum are co-deposited, the catalytic activity of the composite electrode is further improved; meanwhile, compared with the nano particles formed by single metal, the gold-platinum bimetal nano particles have strong toxicity resistance (small probability of pollution and failure), so that the gold-platinum bimetal nano particles can be recycled for many times, and the cost is saved.
(3) The gold-platinum bimetallic nanoparticles exist on the surface of the polyaniline/graphene composite layer in a nanoparticle shape, and the particle size is small and the particles are not agglomerated, so that the specific surface area of the composite electrode can be increased.
(4) The detection sensitivity of the composite electrode to the hormone and whether various hormones can be distinguished are related to the conductivity, the specific surface area and the catalytic activity of the composite electrode, wherein the conductivity is high, which indicates that the mass transfer is fast, so that the oxidation peaks of the hormones with various oxidation potentials close to each other can be distinguished; the specific surface area is large, the more sites can be subjected to catalytic reaction, so that the electrochemical signal is strong, and the detection sensitivity is favorably improved; the catalytic activity is strong, which shows that the catalytic rate is high, the corresponding speed of the electrode is high, the electrochemical signal intensity can be improved, and the method is also beneficial to distinguishing the oxidation peaks of various hormones; in addition, the catalysis has specificity, and a specific type of catalyst is required for detecting a specific type of hormone;
in conclusion, the composite electrode supports each part, and not only can be used for independently detecting any one of dopamine, 5-hydroxytryptamine and melatonin, but also can be used for simultaneously detecting and distinguishing the three hormones.
In some embodiments of the present invention, the conductive substrate is made of at least one of gold, copper, nickel and glassy carbon.
In some preferred embodiments of the present invention, the conductive substrate is made of gold.
In some embodiments of the present invention, the gold-platinum bimetallic nanoparticles refer to nanoparticles containing two metal elements, namely gold and platinum, and the two metal elements may be present in the form of an alloy, a mixture of two simple metals, or a secondary mixture of the two metal elements.
In some embodiments of the present invention, the gold-platinum bimetallic nanoparticles have a particle size between 20nm and 200 nm.
In some embodiments of the invention, the composite electrode has a charge transfer resistance of 2.26 Ω cm or less 2
In some preferred embodiments of the invention, the composite electrode is coated with 2mM [ Fe (CN) with 0.1M KCl as supporting electrolyte 6 ] 3-/4- In the solution, the charge transfer resistance was 2.26. Omega. Cm 2 。
Said [ Fe (CN) 6 ] 3-/4- Solution means that in solution [ Fe (CN) occurs 6 ] 4- And [ Fe (CN) 6 ] 3- The conversion reaction between them.
The 0.1M KCl is 2mM of [ Fe (CN) 6 ] supporting electrolyte] 3-/4- The solution contains KCl with concentration of 0.1M and K with concentration of 2mM 3 [Fe(CN) 6 ]And 2mM of K 4 [Fe(CN) 6 ]。
According to still another aspect of the present invention, there is provided a method of manufacturing a composite electrode, comprising the steps of:
s1, arranging the polyaniline/graphene composite layer on the surface of the conductive matrix by adopting an electrodeposition method;
s2, depositing the gold-platinum bimetallic nanoparticles on the surface of the material obtained in the step S1 by adopting an electrodeposition method to obtain the composite electrode.
The preparation method according to a preferred embodiment of the present invention has at least the following advantageous effects:
the preparation method provided by the invention can obtain the composite electrode only by an electrochemical deposition method, and is simple, easy to implement and high-efficiency.
In some embodiments of the invention, in step S1, the electrodeposition method includes graphene and aniline in a deposition solution.
In some preferred embodiments of the present invention, in the electrodeposition method, in step S1, the deposition solution further comprises an acid.
In some preferred embodiments of the present invention, in step S1, the electrodeposition method further comprises hydrogen chloride (HCl) and sulfuric acid (H) 2 SO 4 ) At least one of (1).
The acid is used for providing doped protons in the polymerization process of the aniline so that the aniline is polymerized to generate a semi-oxidized state, and further the conductivity of the polyaniline is improved.
In some embodiments of the invention, in step S1, the electrodeposition method, the preparing step of the deposition solution comprises:
D1. firstly, adding the graphene powder into a first dispersing agent, and carrying out ultrasonic treatment for 30min to form graphene dispersion liquid which is uniformly dispersed and has the concentration of 0.5-2 mg/mL;
D2. adding 5-50 mL of HCl solution with the concentration of 0.08M into each 100 mu L of graphene dispersion solution, and performing ultrasonic treatment for 3h to form uniform suspension;
D3. and D, taking 10mL of the suspension obtained in the step D2, adding 50-100 mu L of aniline, and performing ultrasonic treatment for 30min to obtain the deposition solution.
In some embodiments of the invention, in step D1, the first dispersant is at least one of deionized water, methanol, absolute ethanol, isopropanol, N-methylformamide, and dimethylformamide.
In some embodiments of the invention, in step S1, the electrodeposition method is at least one of cyclic voltammetry, galvanostatic, and potentiostatic methods.
In some preferred embodiments of the present invention, when the cyclic voltammetry is used as the electrodeposition method in step S1, the scan rate is 25mV/S to 100mV/S, the scan potential is-0.3V to 0.7V, and the number of cycles is 15 to 25.
In some embodiments of the present invention, when the electrodeposition method in step S1 adopts the cyclic voltammetry, the cyclic voltammetry is performed in a three-electrode system, specifically, the conductive substrate is used as a working electrode, commercial Ag/AgCl is used as a reference electrode, and a platinum sheet is used as a counter electrode.
In some preferred embodiments of the present invention, when the electrodeposition method employs the galvanostatic method in step S1, the voltage is set between-0.1 and-0.8V, and the deposition time is between 600 and 2400S.
In some preferred embodiments of the present invention, when the electrodeposition method employs the potentiostatic method in step S1, the current density is in the range of-0.01 to-0.1A/cm 2 The deposition time is between 600 and 2400 s.
The film obtained by adopting the cyclic voltammetry deposition is thinner, and the adhesion between the polyaniline/graphene composite layer obtained by the method and the conductive matrix is stronger, namely the mechanical strength of the obtained composite electrode is higher.
In some embodiments of the present invention, the preparation method further includes, between step S1 and step S2, cleaning the conductive substrate coated with the polyaniline/graphene composite layer, and drying; specifically, the conductive substrate coated with the polyaniline/graphene composite layer is washed by deionized water and then placed in an oven at 40-60 ℃ for drying for 10 hours.
In some embodiments of the present invention, in step S2, the electrodeposition method includes chloroauric acid and chloroplatinic acid in the deposition solution.
In some embodiments of the invention, in step S2, the electrodeposition method further comprises salt in the deposition solution, wherein the salt is selected from potassium chloride (KCl), sodium chloride (NaCl) and sodium sulfate (Na) 2 SO 4 ) At least one of (1).
In step S2, the salt in the deposition solution acts to enhance the conductivity of the deposition solution.
In some embodiments of the invention, in step S2, the electrodeposition method, the preparing step of the deposition solution comprises: adding 0.5 mM-2 mM chloroauric acid solution and 0.5 mM-2 mM chloroplatinic acid solution into 0.1M-0.5M KCl solution, and uniformly stirring; the volume ratio of the KCl solution to the chloroauric acid solution to the chloroplatinic acid solution is (50-200): 1.
In some embodiments of the present invention, in step S2, the electrodeposition method is at least one of a galvanostatic method, a potentiostatic method, and a cyclic voltammetry method.
In some preferred embodiments of the present invention, in step S2, when the electrodeposition method employs the galvanostatic method, the deposition potential is-0.2V to-0.5V, and the deposition time is 180S to 360S.
In some preferred embodiments of the present invention, in step S2, when the electrodeposition method employs the potentiostatic method, the current density is from-0.02 to 0.1mA/cm 2 。
In some preferred embodiments of the present invention, in step S2, when the cyclic voltammetry is used for the electrodeposition, the scanning potential is 0.2 to-0.4V, the scanning speed is 25 to 100mV/S, and the number of turns is 3 to 10 turns.
In some embodiments of the present invention, the amperometric method is performed in a three-electrode system, and specifically, the conductive substrate coated with the polyaniline/graphene composite layer obtained in step S1 is used as a working electrode, a commercial Ag/AgCl is used as a reference electrode, and a platinum sheet is used as a counter electrode.
In some embodiments of the present invention, the method further comprises washing the composite electrode with water after depositing the gold-platinum bimetallic nanoparticles.
According to a further aspect of the invention, the use of the composite electrode for detecting hormones is proposed.
The application of a preferred embodiment according to the present invention has at least the following advantageous effects:
the method for detecting the hormone by using the composite electrode is easy to operate: the special electrode structure can realize the real-time detection of a sampling site in a complex environment, does not need complex processing procedures in laboratory detection, and greatly improves the detection efficiency.
In some embodiments of the invention, the hormone is at least one of dopamine, 5-hydroxytryptamine, and melatonin.
In some embodiments of the present invention, the use of the composite electrode in detecting hormone comprises preparing the composite electrode as a portable detection sensing device for detecting hormone(s).
A detection sensor comprising the composite electrode.
In some embodiments of the invention, the detection sensor is a portable detection sensor.
A detection system comprising the detection sensor.
Drawings
The invention is further described with reference to the following figures and examples, in which:
FIG. 1 is a scanning electron micrograph of a composite electrode obtained in example 1 of the present invention;
FIG. 2 is a differential pulse voltammogram of a composite electrode obtained in example 1 of the present invention with respect to dopamine;
FIG. 3 is a graph of differential pulse voltammetry of a composite electrode pair of 5-hydroxytryptamine obtained in example 1 of the present invention;
FIG. 4 is a differential pulse voltammogram of the composite electrode obtained in example 1 of the present invention against melatonin;
FIG. 5 is a differential pulse voltammetry curve of the composite electrode obtained in example 1 of the present invention for simultaneously detecting dopamine, 5-hydroxytryptamine and melatonin;
FIG. 6 is a differential pulse voltammetry curve of the composite electrode obtained in example 1 of the present invention and the comparative example for simultaneously detecting dopamine, 5-hydroxytryptamine and melatonin;
FIG. 7 is a plot of the AC impedance of gold and a composite electrode obtained in example 1 of the present invention.
Detailed Description
The idea of the invention and the resulting technical effects will be clearly and completely described below in connection with the embodiments, so that the objects, features and effects of the invention can be fully understood. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and other embodiments obtained by those skilled in the art without inventive efforts are within the protection scope of the present invention based on the embodiments of the present invention.
Example 1
In this embodiment, a composite electrode is prepared, which specifically comprises the following steps:
s1, modifying a conductive substrate by using a polyaniline/graphene composite layer:
s1a, preparing a first deposition solution: firstly, adding graphene powder into a methanol solution, and carrying out ultrasonic treatment for 30min to form a graphene dispersion liquid which is uniformly dispersed and has a concentration of 1 mg/mL;
adding 10mL of HCl solution (0.08M) into each 100 mu L of graphene dispersion solution, and performing ultrasonic treatment for 3h to form uniform suspension;
taking 10mL of the suspension, adding 70 mu L of aniline (analytically pure liquid aniline), and carrying out ultrasonic treatment for 30min to obtain a first deposition solution;
s1b, depositing a polyaniline/graphene composite layer: adopting a three-electrode system, taking planar gold (conductive matrix) as a working electrode, commercial Ag/AgCl as a reference electrode and a platinum sheet as a counter electrode, in a first deposition solution, performing cyclic voltammetry at a scanning speed of 50mV/s and a scanning potential of-0.3V-0.7V for 15 circles, cleaning the obtained intermediate electrode with deionized water, and then putting the cleaned intermediate electrode into a 60 ℃ drying oven to dry for 10 hours to obtain the conductive matrix modified by a polyaniline/graphene composite layer;
s2, modifying the electrode obtained in the step S1 by gold-platinum bimetallic nanoparticles:
s2a, preparing a second deposition solution: adding a 1mM chloroauric acid solution and a 1mM chloroplatinic acid solution into a 0.1M KCl solution, and uniformly stirring to obtain a second deposition solution; the volume ratio of the KCl solution to the chloroauric acid solution to the chloroplatinic acid solution is 100;
s2b, depositing gold-platinum bimetallic nanoparticles: adopting a three-electrode system, taking the electrode prepared in the step S1 as a working electrode, taking commercial Ag/AgCl as a reference electrode and a platinum sheet as a counter electrode, and depositing gold-platinum bimetallic nanoparticles on the surface of the electrode obtained in the step S1 in a second deposition solution by a chronoamperometry; the deposition potential is-0.2V, the deposition time is 240s, and the composite electrode is obtained after the electrodeposition is finished and is washed clean by deionized water.
Example 2
In this example, a composite electrode was prepared, which is different from example 1 in that:
(1) In step S1b, 20 cycles are performed.
Example 3
In this example, a composite electrode was prepared, which is different from example 1 in that:
(1) In step S2b, the deposition potential is-0.3V and the deposition time is 180S.
Example 4
In this example, a composite electrode was prepared, which specifically differs from example 4 in that:
(1) In the step S1a, the concentration of the graphene dispersion liquid is 2mg/mL;
(2) In step S2a, the concentrations of chloroauric acid and chloroplatinic acid were 0.5mM each.
Comparative example 1
This comparative example prepared a composite electrode, differing from example 1 in that:
(1) Step S2 is not included, namely, the product obtained in step S1 is directly used as a composite electrode.
Comparative example 2
This comparative example prepared a composite electrode, differing from example 1 in that:
(1) In step S2a, chloroplatinic acid was not added.
Comparative example 3
This comparative example prepared a composite electrode, differing from example 1 in that:
(1) In step S2a, chloroauric acid was not added.
Comparative example 4
This comparative example prepared a composite electrode, differing from example 1 in that:
(1) In step S1a, the aniline solution is not included, i.e. the suspension formed after the ultrasonication for 3 hours is directly used as the first deposition solution.
Test examples
This test example tested the performance of the composite electrodes prepared in the examples and comparative examples.
In the first aspect of this test example, the morphology performance of the composite electrode obtained in example 1 was tested by a scanning electron microscope, and the test results are shown in fig. 1.
The results in fig. 1 show that gold-platinum bimetallic nanoparticles are uniformly distributed on the surface of the composite electrode obtained in example 1, and no agglomeration phenomenon occurs; the morphology of the composite electrodes obtained in examples 2 to 4 was similar to that of the composite electrode obtained in example 1.
In a second aspect of this test example, the response performance of the composite electrode obtained in example 1 to a single kind of dopamine, 5-hydroxytryptamine or melatonin was tested, and the test method was differential pulse voltammetry, specifically, the composite electrode obtained in example 1 was used as a working electrode, an Ag/AgCl electrode was used as a reference electrode, a Pt sheet was used as a counter electrode, and a solution of dopamine, 5-hydroxytryptamine or melatonin at an appropriate concentration was added to a 0.1M phosphate buffer solution (pH 7.0), and scanned by differential pulse voltammetry to determine the change curve of the peak current.
FIG. 2 is a differential pulse voltammetry curve of the composite electrode obtained in example 1 of the present invention for detecting dopamine solutions at concentrations of 1. Mu.M, 3. Mu.M, 5. Mu.M, 7. Mu.M, 10. Mu.M, 15. Mu.M, 20. Mu.M, 30. Mu.M, 50. Mu.M, 70. Mu.M, 100. Mu.M, 150. Mu.M, 200. Mu.M and 300. Mu.M, respectively;
FIG. 3 is a differential pulse voltammetry curve of the composite electrode obtained in example 1 of the present invention for detecting 5-hydroxytryptamine solutions with concentrations of 1. Mu.M, 5. Mu.M, 15. Mu.M, 50. Mu.M, 70. Mu.M, 100. Mu.M, 200. Mu.M, and 300. Mu.M, respectively;
FIG. 4 is a differential pulse voltammetry curve of the composite electrode obtained in example 1 of the present invention for detecting melatonin solutions at concentrations of 1. Mu.M, 5. Mu.M, 15. Mu.M, 30. Mu.M, 50. Mu.M, 70. Mu.M, 100. Mu.M, 150. Mu.M, 200. Mu.M and 300. Mu.M, respectively; 2-4, the abscissa E of the differential pulse voltammogram represents voltage in volts (V) based on Ag/AgCl; the ordinate j is the current density.
As can be seen from fig. 2 to 4, the peak current density gradually increased with increasing concentrations of Dopamine (DA), 5-hydroxytryptamine (5-HT) and Melatonin (MEL), indicating that the composite electrode prepared according to the present invention has excellent response characteristics to trace amounts of dopamine, 5-hydroxytryptamine and melatonin. The performance of the composite electrodes obtained in examples 2 to 4 was comparable to that of the composite electrodes obtained in the examples.
In the third aspect of this test example, the response performance of the composite electrode obtained in example 1 to dopamine, 5-hydroxytryptamine and melatonin are tested together, 7 times of gradient tests are performed, the contents of three hormones in the solution to be tested are shown in table 1, and the difference between the specific method and the second aspect of this test example is: the solution contains dopamine, 5-hydroxytryptamine and melatonin simultaneously in a 0.1M phosphoric acid buffer solution (pH 7.0), wherein the specific concentrations of dopamine, 5-hydroxytryptamine and melatonin are shown in Table 1.
TABLE 1 specific concentrations of dopamine, 5-hydroxytryptamine and melatonin in FIG. 5
| Test number | Test No. 1 | Test No. 2 | Test No. 3 | Test No. 4 | Test No. 5 | Test No. 6 | Test No. 7 |
| Dopamine | 1μM | 3μM | 5μM | 7μM | 15μM | 50μM | 100μM |
| 5-hydroxytryptamine | 1μM | 3μM | 5μM | 7μM | 15μM | 50μM | 100μM |
| 5-hydroxytryptamine | 1μM | 3μM | 5μM | 7μM | 15μM | 50μM | 100μM |
The results are shown in FIG. 5, where the abscissa E represents the voltage in volts (V) based on Ag/AgCl; the ordinate j is the current density. As can be seen from the figure:
the peak position of the differential pulse curve is gradually increased along with the increase of the concentrations of dopamine, 5-hydroxytryptamine and melatonin;
the differential pulse curve shows three distinct oxidation peaks which respectively correspond to the oxidation peaks of Dopamine (DA), 5-hydroxytryptamine (5-HT) and Melatonin (MEL), and shows that the three hormones all have good electrochemical responsiveness on the composite electrode obtained in example 1;
the oxidation peak potentials of dopamine, 5-hydroxytryptamine and melatonin are different, and the oxidation peak potentials do not interfere with the measurement, so that the composite electrode prepared by the method can be used for simultaneously detecting the dopamine, 5-hydroxytryptamine and melatonin; the performance of the composite electrodes obtained in examples 2 to 4 was comparable to that of the composite electrodes obtained in the examples.
In conclusion, the invention establishes an electrochemical new method for simultaneously measuring dopamine, 5-hydroxytryptamine and melatonin.
In the fourth aspect of the present test example, the composite electrodes obtained in example 1 and the comparative example were tested for their effects in detecting three hormones, namely, dopamine, 5-hydroxytryptamine and melatonin, and the difference between the test method and the third aspect of the present test example is that the working electrode employs the composite electrode obtained in the comparative example in addition to the composite electrode obtained in example 1.
The results are shown in FIG. 6, where the abscissa E represents the voltage in volts (V) based on Ag/AgCl; the ordinate j is the current density. It is shown that the composite electrode obtained in example 1 shows oxidation peaks of each hormone in terms of the effect of detecting three hormones, dopamine, 5-hydroxytryptamine and melatonin, and the response intensity is superior to that of the composite electrode obtained in all comparative examples; specifically, if the gold-platinum bimetallic nanoparticles are not included in the composite electrode, the obtained composite electrode has no response to melatonin; if pure gold nanoparticles or platinum nanoparticles are used for replacing gold-platinum bimetallic nanoparticles, or polyaniline is not included in the composite electrode, the obtained composite electrode has response to the three hormones, but the response strength is low; the composite electrode provided by the invention has the advantages that all parts generate synergistic action, and the response characteristics of the composite electrode to the three hormones are improved together.
In the fifth aspect of this test example, the composite electrode obtained in example 1 was tested, and an EIS (alternating current impedance) spectrum of gold was obtained, and the results are shown in fig. 7, in which the abscissa is real-part impedance and the ordinate is imaginary-part impedance.
The results in FIG. 7 show that the charge transfer resistance of gold is about 15.94. Omega. Cm 2 The charge transfer resistance of the composite electrode obtained in example 1 was much lower than that of gold, about 2.2. Omega. Cm 2 。
The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the gist of the present invention. Furthermore, the embodiments of the present invention and the features of the embodiments may be combined with each other without conflict.
Claims (9)
1. The application of the composite electrode in simultaneously detecting three hormones of dopamine, 5-hydroxytryptamine and melatonin is characterized in that the composite electrode comprises:
a conductive base;
a polyaniline/graphene composite layer; the polyaniline/graphene composite layer is coated on the surface of the conductive substrate;
gold-platinum bimetallic nanoparticles; the gold-platinum bimetallic nanoparticles are deposited on the surface of the polyaniline/graphene composite layer.
2. The use according to claim 1, wherein the conductive substrate is at least one of gold, copper, nickel and glassy carbon.
3. The use as claimed in claim 1, wherein the bimetallic Au-Pt nanoparticle has a particle size of 20 to 200nm.
4. The use of claim 1, wherein the combined electrode has a charge transfer resistance of 2.26 Ω cm or less 2 。
5. The use according to any one of claims 1 to 4, wherein the preparation method of the composite electrode comprises the following steps:
s1, arranging the polyaniline/graphene composite layer on the surface of the conductive matrix by adopting an electrodeposition method;
s2, depositing the gold-platinum bimetallic nanoparticles on the surface of the material obtained in the step S1 by adopting an electrodeposition method to obtain the composite electrode.
6. The use of claim 5, wherein in step S1, the electrodeposition solution comprises graphene and aniline.
7. The use of claim 6, wherein the electrodeposition method is at least one of cyclic voltammetry, galvanostatic, and potentiostatic.
8. The use of claim 5, wherein in step S2, the electrodeposition process comprises chloroauric acid and chloroplatinic acid in the deposition solution.
9. The use of claim 8, wherein the electrodeposition is at least one of galvanostatic, potentiostatic, and cyclic voltammetry.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110583541.1A CN113406171B (en) | 2021-05-27 | 2021-05-27 | Composite electrode and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110583541.1A CN113406171B (en) | 2021-05-27 | 2021-05-27 | Composite electrode and preparation method and application thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113406171A CN113406171A (en) | 2021-09-17 |
| CN113406171B true CN113406171B (en) | 2022-11-18 |
Family
ID=77674591
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110583541.1A Active CN113406171B (en) | 2021-05-27 | 2021-05-27 | Composite electrode and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113406171B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114740063B (en) * | 2022-02-16 | 2024-05-17 | 陕西化工研究院有限公司 | Method for detecting hydrazine by adopting electrochemistry |
| US11819833B2 (en) * | 2022-03-22 | 2023-11-21 | Najran University | Conducting polymer and carbon nitride based nanocomposite photocatalyst for degradation of aqueous organic pollutants |
| CN115137312B (en) * | 2022-08-31 | 2023-01-24 | 首都医科大学附属北京同仁医院 | Sleep quality evaluation method and device and wearable device |
| CN115137313B (en) * | 2022-08-31 | 2022-11-18 | 首都医科大学附属北京同仁医院 | Evaluation method and device for simultaneously aiming at sleep quality and myopia risk |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102219390A (en) * | 2011-03-18 | 2011-10-19 | 南京邮电大学 | Layered grapheme polyaniline composite film and preparation method thereof |
| CN103499627B (en) * | 2013-10-18 | 2015-07-29 | 山东理工大学 | A kind of preparation method detecting the aptamer sensor of yapamicin relict |
| CN104950027A (en) * | 2015-06-20 | 2015-09-30 | 常州大学 | Synthesis of graphene/polyaniline/gold nanoparticle composite material and application thereof to dopamine detection |
| CN105788880B (en) * | 2016-04-15 | 2018-05-25 | 上海交通大学 | A kind of graphene-polyaniline nanoparticles composite film electrode and preparation method thereof |
| CN106058278A (en) * | 2016-06-13 | 2016-10-26 | 江苏大学 | One-step in-situ preparation method of graphene/polyaniline composite electrode |
| CN106169379B (en) * | 2016-09-28 | 2018-07-20 | 唐山学院 | A method of preparing graphite paper/carbon nanotube-graphene/polyaniline flexible compound electrode |
| CN109580747B (en) * | 2018-11-30 | 2020-10-16 | 河南省科学院能源研究所有限公司 | Electrochemical sensor for detecting dopamine |
-
2021
- 2021-05-27 CN CN202110583541.1A patent/CN113406171B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN113406171A (en) | 2021-09-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113406171B (en) | Composite electrode and preparation method and application thereof | |
| Xu et al. | A novel flexible electrochemical glucose sensor based on gold nanoparticles/polyaniline arrays/carbon cloth electrode | |
| Ekram et al. | Electrochemistry of glucose at gold nanoparticles modified graphite/SrPdO3 electrode–towards a novel non-enzymatic glucose sensor | |
| Liu et al. | Electrochemical preparation of nickel and copper oxides-decorated graphene composite for simultaneous determination of dopamine, acetaminophen and tryptophan | |
| Abdelwahab et al. | Simultaneous determination of ascorbic acid, dopamine, uric acid and folic acid based on activated graphene/MWCNT nanocomposite loaded Au nanoclusters | |
| Salahandish et al. | Sandwich-structured nanoparticles-grafted functionalized graphene based 3D nanocomposites for high-performance biosensors to detect ascorbic acid biomolecule | |
| Han et al. | Porous gold cluster film prepared from Au@ BSA microspheres for electrochemical nonenzymatic glucose sensor | |
| Atta et al. | A novel sensor of cysteine self-assembled monolayers over gold nanoparticles for the selective determination of epinephrine in presence of sodium dodecyl sulfate | |
| Li et al. | Simultaneous determination of dopamine and serotonin on gold nanocluster/overoxidized-polypyrrole composite modified glassy carbon electrode | |
| Li et al. | Electrochemical investigation of tryptophan at gold nanoparticles modified electrode in the presence of sodium dodecylbenzene sulfonate | |
| Wei et al. | Simultaneous detection of ascorbic acid, dopamine, and uric acid using a novel electrochemical sensor based on palladium nanoparticles/reduced graphene oxide nanocomposite | |
| Yang et al. | Fabrication of nano-copper/carbon nanotubes/chitosan film by one-step electrodeposition and its sensitive determination of nitrite | |
| Shi et al. | An ascorbic acid amperometric sensor using over-oxidized polypyrrole and palladium nanoparticles composites | |
| Wan et al. | A novel electrochemical sensor based on Ag nanoparticles decorated multi-walled carbon nanotubes for applied determination of nitrite | |
| Yang et al. | Simultaneous determination of ascorbic acid, uric acid, tryptophan and adenine using carbon-supported NiCoO2 nanoparticles | |
| CN106383158B (en) | A kind of hydrogen peroxide based on silver-graphene nano-complex is without enzyme sensor and preparation method thereof | |
| Li et al. | Amperometric cholesterol biosensor based on reduction graphene oxide-chitosan-ferrocene/platinum nanoparticles modified screen-printed electrode | |
| Edris et al. | Electrochemical reduced graphene oxide-poly (eriochrome black T)/gold nanoparticles modified glassy carbon electrode for simultaneous determination of ascorbic acid, dopamine and uric acid | |
| Yi et al. | Palladium nanoparticles entrapped in a self-supporting nanoporous gold wire as sensitive dopamine biosensor | |
| Tian et al. | Amperometric detection of glucose based on immobilizing glucose oxidase on g-C3N4 nanosheets | |
| Huang et al. | Non-enzymatic electrochemical hydrogen peroxide biosensor based on reduction graphene oxide-persimmon tannin‑platinum nanocomposite | |
| Unnikrishnan et al. | Nitrite determination at electrochemically synthesized polydiphenylamine-Pt composite modified glassy carbon electrode | |
| Zhai et al. | Core-shell composite N-doped-Co-MOF@ polydopamine decorated with Ag nanoparticles for nonenzymatic glucose sensors | |
| Du et al. | A nanocomposite-based electrochemical sensor for non-enzymatic detection of hydrogen peroxide | |
| McCormick et al. | Development of a highly nanoporous platinum screen-printed electrode and its application in glucose sensing |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |