CN115201309A - Preparation method and application of hydroxyl radical electrochemical sensor - Google Patents
Preparation method and application of hydroxyl radical electrochemical sensor Download PDFInfo
- Publication number
- CN115201309A CN115201309A CN202210970605.8A CN202210970605A CN115201309A CN 115201309 A CN115201309 A CN 115201309A CN 202210970605 A CN202210970605 A CN 202210970605A CN 115201309 A CN115201309 A CN 115201309A
- Authority
- CN
- China
- Prior art keywords
- solution
- electrode
- hydroxybenzoic acid
- concentration
- hydroxyl radical
- 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.)
- Granted
Links
- TUJKJAMUKRIRHC-UHFFFAOYSA-N hydroxyl Chemical compound [OH] TUJKJAMUKRIRHC-UHFFFAOYSA-N 0.000 title claims abstract description 34
- 238000002360 preparation method Methods 0.000 title claims abstract description 9
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 claims abstract description 26
- 238000000034 method Methods 0.000 claims abstract description 25
- 238000001514 detection method Methods 0.000 claims abstract description 24
- 239000000243 solution Substances 0.000 claims description 86
- 229940090248 4-hydroxybenzoic acid Drugs 0.000 claims description 32
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 32
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 23
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 20
- 238000006243 chemical reaction Methods 0.000 claims description 18
- 229920001661 Chitosan Polymers 0.000 claims description 14
- 238000001903 differential pulse voltammetry Methods 0.000 claims description 13
- 238000006116 polymerization reaction Methods 0.000 claims description 12
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 10
- 239000003431 cross linking reagent Substances 0.000 claims description 10
- 239000003999 initiator Substances 0.000 claims description 10
- 229910052757 nitrogen Inorganic materials 0.000 claims description 10
- 239000002048 multi walled nanotube Substances 0.000 claims description 9
- 238000005406 washing Methods 0.000 claims description 9
- 238000001035 drying Methods 0.000 claims description 8
- 239000000178 monomer Substances 0.000 claims description 8
- 239000002253 acid Substances 0.000 claims description 7
- 239000007787 solid Substances 0.000 claims description 7
- 239000011259 mixed solution Substances 0.000 claims description 6
- 238000010828 elution Methods 0.000 claims description 5
- 239000007788 liquid Substances 0.000 claims description 5
- 229920000642 polymer Polymers 0.000 claims description 5
- MYRTYDVEIRVNKP-UHFFFAOYSA-N 1,2-Divinylbenzene Chemical compound C=CC1=CC=CC=C1C=C MYRTYDVEIRVNKP-UHFFFAOYSA-N 0.000 claims description 4
- 239000002041 carbon nanotube Substances 0.000 claims description 4
- 229910021393 carbon nanotube Inorganic materials 0.000 claims description 4
- 238000000970 chrono-amperometry Methods 0.000 claims description 4
- 238000001816 cooling Methods 0.000 claims description 4
- 238000011049 filling Methods 0.000 claims description 4
- 238000003760 magnetic stirring Methods 0.000 claims description 4
- 238000002156 mixing Methods 0.000 claims description 4
- 230000007935 neutral effect Effects 0.000 claims description 4
- 238000007789 sealing Methods 0.000 claims description 4
- 238000000967 suction filtration Methods 0.000 claims description 4
- 238000001291 vacuum drying Methods 0.000 claims description 4
- OZAIFHULBGXAKX-UHFFFAOYSA-N 2-(2-cyanopropan-2-yldiazenyl)-2-methylpropanenitrile Chemical compound N#CC(C)(C)N=NC(C)(C)C#N OZAIFHULBGXAKX-UHFFFAOYSA-N 0.000 claims description 3
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 claims description 3
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 claims description 3
- BRLQWZUYTZBJKN-UHFFFAOYSA-N Epichlorohydrin Chemical compound ClCC1CO1 BRLQWZUYTZBJKN-UHFFFAOYSA-N 0.000 claims description 3
- SXRSQZLOMIGNAQ-UHFFFAOYSA-N Glutaraldehyde Chemical compound O=CCCCC=O SXRSQZLOMIGNAQ-UHFFFAOYSA-N 0.000 claims description 3
- CERQOIWHTDAKMF-UHFFFAOYSA-N Methacrylic acid Chemical compound CC(=C)C(O)=O CERQOIWHTDAKMF-UHFFFAOYSA-N 0.000 claims description 3
- 230000004913 activation Effects 0.000 claims description 3
- 239000007864 aqueous solution Substances 0.000 claims description 3
- 229910052799 carbon Inorganic materials 0.000 claims description 3
- 238000002484 cyclic voltammetry Methods 0.000 claims description 3
- 229910021397 glassy carbon Inorganic materials 0.000 claims description 3
- 239000010439 graphite Substances 0.000 claims description 3
- 229910002804 graphite Inorganic materials 0.000 claims description 3
- JAHNSTQSQJOJLO-UHFFFAOYSA-N 2-(3-fluorophenyl)-1h-imidazole Chemical compound FC1=CC=CC(C=2NC=CN=2)=C1 JAHNSTQSQJOJLO-UHFFFAOYSA-N 0.000 claims description 2
- XUDBVJCTLZTSDC-UHFFFAOYSA-N 2-ethenylbenzoic acid Chemical compound OC(=O)C1=CC=CC=C1C=C XUDBVJCTLZTSDC-UHFFFAOYSA-N 0.000 claims description 2
- KGIGUEBEKRSTEW-UHFFFAOYSA-N 2-vinylpyridine Chemical compound C=CC1=CC=CC=N1 KGIGUEBEKRSTEW-UHFFFAOYSA-N 0.000 claims description 2
- DBCAQXHNJOFNGC-UHFFFAOYSA-N 4-bromo-1,1,1-trifluorobutane Chemical compound FC(F)(F)CCCBr DBCAQXHNJOFNGC-UHFFFAOYSA-N 0.000 claims description 2
- KFDVPJUYSDEJTH-UHFFFAOYSA-N 4-ethenylpyridine Chemical compound C=CC1=CC=NC=C1 KFDVPJUYSDEJTH-UHFFFAOYSA-N 0.000 claims description 2
- 230000008859 change Effects 0.000 claims description 2
- 239000003795 chemical substances by application Substances 0.000 claims description 2
- STVZJERGLQHEKB-UHFFFAOYSA-N ethylene glycol dimethacrylate Substances CC(=C)C(=O)OCCOC(=O)C(C)=C STVZJERGLQHEKB-UHFFFAOYSA-N 0.000 claims description 2
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 claims description 2
- 229910052737 gold Inorganic materials 0.000 claims description 2
- 239000010931 gold Substances 0.000 claims description 2
- LVHBHZANLOWSRM-UHFFFAOYSA-N methylenebutanedioic acid Natural products OC(=O)CC(=C)C(O)=O LVHBHZANLOWSRM-UHFFFAOYSA-N 0.000 claims description 2
- 239000008055 phosphate buffer solution Substances 0.000 claims description 2
- 238000001132 ultrasonic dispersion Methods 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 claims 1
- 230000004044 response Effects 0.000 abstract description 10
- 229920000344 molecularly imprinted polymer Polymers 0.000 abstract description 9
- 238000004458 analytical method Methods 0.000 abstract description 8
- 239000000126 substance Substances 0.000 abstract description 6
- 230000008569 process Effects 0.000 abstract description 5
- 230000035945 sensitivity Effects 0.000 abstract description 4
- 238000012662 bulk polymerization Methods 0.000 abstract description 3
- 125000002887 hydroxy group Chemical group [H]O* 0.000 abstract description 3
- 230000033444 hydroxylation Effects 0.000 abstract description 3
- 238000005805 hydroxylation reaction Methods 0.000 abstract description 3
- 239000007772 electrode material Substances 0.000 abstract description 2
- 238000005070 sampling Methods 0.000 abstract 1
- 230000002195 synergetic effect Effects 0.000 abstract 1
- WXTMDXOMEHJXQO-UHFFFAOYSA-N 2,5-dihydroxybenzoic acid Chemical compound OC(=O)C1=CC(O)=CC=C1O WXTMDXOMEHJXQO-UHFFFAOYSA-N 0.000 description 5
- YQUVCSBJEUQKSH-UHFFFAOYSA-M 3,4-dihydroxybenzoate Chemical compound OC1=CC=C(C([O-])=O)C=C1O YQUVCSBJEUQKSH-UHFFFAOYSA-M 0.000 description 5
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 4
- YGSDEFSMJLZEOE-UHFFFAOYSA-N salicylic acid Chemical compound OC(=O)C1=CC=CC=C1O YGSDEFSMJLZEOE-UHFFFAOYSA-N 0.000 description 4
- 238000009210 therapy by ultrasound Methods 0.000 description 4
- 239000008151 electrolyte solution Substances 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- FJKROLUGYXJWQN-UHFFFAOYSA-N papa-hydroxy-benzoic acid Natural products OC(=O)C1=CC=C(O)C=C1 FJKROLUGYXJWQN-UHFFFAOYSA-N 0.000 description 3
- 239000000523 sample Substances 0.000 description 3
- 238000001179 sorption measurement Methods 0.000 description 3
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 2
- 239000012496 blank sample Substances 0.000 description 2
- 239000007853 buffer solution Substances 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 238000002189 fluorescence spectrum Methods 0.000 description 2
- 238000002329 infrared spectrum Methods 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 239000002516 radical scavenger Substances 0.000 description 2
- 229960004889 salicylic acid Drugs 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- 238000004832 voltammetry Methods 0.000 description 2
- 125000004203 4-hydroxyphenyl group Chemical group [H]OC1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 description 1
- 238000004435 EPR spectroscopy Methods 0.000 description 1
- 229910021607 Silver chloride Inorganic materials 0.000 description 1
- 229910010413 TiO 2 Inorganic materials 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 238000004587 chromatography analysis Methods 0.000 description 1
- 125000004122 cyclic group Chemical group 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005868 electrolysis reaction Methods 0.000 description 1
- 238000002795 fluorescence method Methods 0.000 description 1
- 229920002521 macromolecule Polymers 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000006386 memory function Effects 0.000 description 1
- 239000002086 nanomaterial Substances 0.000 description 1
- 238000000643 oven drying Methods 0.000 description 1
- 239000007800 oxidant agent Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 239000002861 polymer material Substances 0.000 description 1
- 238000007348 radical reaction Methods 0.000 description 1
- 230000027756 respiratory electron transport chain Effects 0.000 description 1
- 238000007650 screen-printing Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- HKZLPVFGJNLROG-UHFFFAOYSA-M silver monochloride Chemical compound [Cl-].[Ag+] HKZLPVFGJNLROG-UHFFFAOYSA-M 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
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
- G01N27/416—Systems
- G01N27/48—Systems using polarography, i.e. measuring changes in current under a slowly-varying voltage
Landscapes
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Health & Medical Sciences (AREA)
- Physics & Mathematics (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Molecular Biology (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analysing Biological Materials (AREA)
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
Abstract
The invention discloses a preparation method of a hydroxyl radical electrochemical sensor, which uses g-C 3 N 4 /MWCNTs-COOH as a modified electrode material at g-C 3 N 4 The MWCNTs-COOH modified electrode surface adopts a bulk polymerization method to prepare a molecularly imprinted polymer, can perform selective recognition response on a specific hydroxylation product, and g-C 3 N 4 Can provide more surface active sites and has good thermal stability; the MWCNTs-COOH has high conductivity and good chemical stability, and the strong synergistic effect between the MWCNTs-COOH and the MWCNTs-COOH can improve the detection sensitivity of the sensor; the target product is analyzed and tested by adopting a differential pulse method, and the electrochemical sensor prepared by adopting a bulk polymerization method has quick response to the imprinted molecules, high sensitivity and good stability; the method has a wider linear detection range and a lower detection limit, is suitable for the free detection and analysis of trace hydroxyl, does not need the processes of sampling and the like in the detection, and simplifies the detection process.
Description
Technical Field
The invention belongs to the technical field of high polymer materials and chemical sensors, and particularly relates to a preparation method and application of a hydroxyl radical electrochemical sensor.
Background
The hydroxyl radical is the most active molecule and one of the most aggressive chemical substances, can almost nonselectively react with all biological macromolecules, organic matters or inorganic matters in various chemical reactions, and has very high reaction rate constant and negatively charged electrophilicity. The hydroxyl radical has extremely strong oxidation performance and is a strong oxidant (E) 0 = 2.80V), the chemical reaction involved is a radical reaction, the chemical reaction rate is extremely fast, once a hydroxyl radical is formed, a series of radical chain reactions are induced, and all organic substances and organisms are oxidatively decomposed. Due to the characteristics of high activity, short service life and easy conversion between the two, the analysis and detection of the compound become a difficult point for research. The traditional analysis methods, such as an electron spin resonance method, a chromatography method, a fluorescence method and the like, have the problems of expensive instruments, complex sample pretreatment process and other possible pollution introduction in the operation process, and limit the application of the traditional analysis methods in certain fields to a certain extent.
Molecular Imprinting Technique (MIT) refers to an experimental preparation Technique for obtaining a polymer that perfectly matches a certain template molecule in spatial structure and binding site, and is a process for selectively recognizing a polymer specifically for a certain target molecule (or called an imprinted molecule or a template molecule). Molecularly Imprinted Polymers (MIPs) have a memory function, and can selectively adsorb target molecules to be detected, so that the molecularly imprinted Polymers are often used as a basis for establishing various selective separation, enrichment and detection methods. Compared with the common chemical sensor, the molecular imprinting sensor has high selectivity, strong specificity and good stability, can avoid the interference of structural analogues in the determination, and can be used for the determination of a certain component in a mixture.
Disclosure of Invention
Aiming at the problems in the prior art, the inventionThe invention provides a preparation method of a hydroxyl radical electrochemical sensor; the method uses g-C 3 N 4 /MWCNTs-COOH as a modified electrode material, g-C 3 N 4 The special structure of the compound provides more surface active sites, and increases the adsorption and good thermal stability of the substrate; MWCNTs-COOH is one of the most widely applied carbon nano materials, has the advantages of high conductivity, good mechanical and chemical stability, high specific surface area, high catalytic activity and the like, has good electron transfer performance and strong adsorption capacity when combined together, and can improve the detection sensitivity; g-C 3 N 4 The MWCNTs-COOH modified electrode is used as an imprinting matrix, a hydroxylation product is used as a template molecule, a molecular imprinting polymer is prepared by adopting a bulk polymerization method, and the electrochemical sensor can perform selective recognition response on the specific hydroxylation product. The purpose of the invention is realized by the following scheme:
(1) Electrode activation treatment
The electrode is washed by water and ethanol for 2 to 4 times in turn, and then the electrode is placed in K containing KCl of 0.01 to 0.02mol/L 3 [Fe(CN) 6 ]-K 4 [Fe(CN) 6 ]Performing cyclic voltammetry scanning in the solution, wherein the scanning potential is-1.0 to +1.0V, and the scanning speed is 0.05 to 0.1V/s, the cyclic scanning is performed for 10 to 20 circles, so that the electrode is activated, and the activated electrode is washed by water and ethanol alternately again and is dried for later use;
the electrode is a carbon electrode, a glassy carbon electrode or a gold electrode, K 3 [Fe(CN) 6 ]-K 4 [Fe(CN) 6 ]The solution contains 0.04 to 0.06mol/L K 3 [Fe(CN) 6 ]And 0.04 to 0.06mol/L K 4 [Fe(CN) 6 ]An aqueous solution of (a);
(2) Modified electrode
Carboxylated multi-wall carbon nano-tubes (MWCNTs-COOH) and graphite phase nitrogen carbide (g-C) 3 N 4 ) Dispersing in an ethanol solution, and performing ultrasonic dispersion to obtain a uniform mixed solution, wherein the concentration of the carboxylated multi-walled carbon nanotube in water is 0.5-1.0 mg/mL, and the concentration of graphite-phase nitrogen carbide in water is 0.5-1.0 mg/mL; wherein the carboxylated multi-walled carbon nanotube is prepared by putting 50-100mg of carbon nanotube into 20-40mL of mixed acid solution at 55-65 DEG CPerforming ultrasonic treatment for 3 to 5 hours, then washing the mixture with water to be neutral, performing suction filtration, and performing vacuum drying on the solid at the temperature of 60 ℃ to obtain the solid, wherein the mixed acid solution is concentrated H 2 SO 4 With concentrated HNO 3 Mixing according to the volume ratio of 2 to 4; the ethanol solution is prepared by mixing ethanol and water according to the volume ratio of 1: 2-4, and the mass ratio of the carboxylated multi-walled carbon nanotube to graphite-phase nitrogen carbide is 1;
dripping 1 to 3 mu L of mixed liquid on the surface of the electrode after activation treatment, and drying for 10 to 20min under an infrared lamp at the temperature of 30 to 60 ℃ to obtain g-C 3 N 4 MWCNTs-COOH modified electrode;
(3) Preparation of polymerization solution
Adding an imprinting molecular solution and a functional monomer solution into a chitosan solution, and carrying out prepolymerization reaction under the magnetic stirring condition of 300 to 500r/min for 1 to 3h to prepare an imprinting solution; then adding a cross-linking agent solution and an initiator solution, filling nitrogen, sealing, reacting in a water bath at 60-80 ℃ for 2-4 h, and naturally cooling the solution after the reaction to room temperature to prepare a polymerization solution;
wherein the concentration of the chitosan solution is 0.01 to 0.05mol/L; the imprinted molecule is 2, 5-p-hydroxybenzoic acid (2, 5-DHBA) or 3, 4-p-hydroxybenzoic acid (3, 4-DHBA), the concentration of the imprinted molecule solution is 0.01 to 0.05mol/L, and the volume ratio of the chitosan solution to the imprinted molecule solution is 5; the functional monomer is one of acrylic acid, methacrylic acid, vinyl benzoic acid, itaconic acid, 2-vinylpyridine and 4-vinylpyridine, the concentration of the functional monomer solution is 0.1 to 0.5mmol/L, and the volume ratio of the chitosan solution to the functional monomer solution is 10; the cross-linking agent is one of ethylene glycol dimethacrylate, divinyl benzene, glutaraldehyde and epichlorohydrin, the concentration of the cross-linking agent solution is 0.7 to 0.9mmol/L, and the volume ratio of the chitosan solution to the cross-linking agent solution is 10 to 1 to 3; the initiator is one of azodiisobutyronitrile and azodiisoheptanenitrile, the concentration of the initiator solution is 0.1 to 0.5mmol/L, and the volume ratio of the chitosan solution to the initiator solution is 10 to 1 to 3;
(4) Polymerization liquid modified electrode
1 to 3 mu L of the polymer is taken to be coated on g-C 3 N 4 Drying the electrode surface modified by/MWCNTs-COOH under an infrared lamp at 30-60 ℃ for 5-10min for preparationUsing;
(5) Removal of template molecules
Placing the electrode modified by the polymerization solution in 0.01 to 0.05mol/L of Na 2 HCO 3 Or NaH 2 CO 3 Removing the template molecule by a chronoamperometry (i-t) under the potential of 0.6 to 1.3V in the elution solution of (4), wherein the elution time is 10 to 20min; thus obtaining the hydroxyl radical electrochemical sensor.
The invention also aims to apply the hydroxyl radical electrochemical sensor prepared by the method in the detection of the hydroxyl radicals.
During detection, a hydroxyl radical electrochemical sensor is used as a working electrode, one end of the working electrode, one end of a counter electrode and one end of a reference electrode are respectively connected to an electrochemical workstation, the other ends of the working electrode, the counter electrode and the reference electrode are respectively placed in a solution containing 2, 5-p-hydroxybenzoic acid or 3, 4-p-hydroxybenzoic acid with known concentration in an electrolytic cell, the solution is placed for standing, adsorbed and identified for 7 to 15min, then the solution is transferred to a phosphoric acid buffer solution with 0.01 to 0.05mol/L and pH of 4 to 6, and detection is carried out by using a Differential Pulse Voltammetry (DPV), wherein during detection, the potential range is 0 to 1.5V, the voltage increment is 0.002 to 0.006V, the pulse amplitude is 0.03 to 0.05V, the pulse width is 0.03 to 0.05s, and the pulse period is 0.1 to 0.3s; recording the current change condition by an electrochemical workstation, drawing a standard curve corresponding to the 2, 5-p-hydroxybenzoic acid or 3, 4-p-hydroxybenzoic acid by taking the logarithm of the concentration of the 2, 5-p-hydroxybenzoic acid or 3, 4-p-hydroxybenzoic acid as an abscissa and the current as an ordinate, obtaining a regression equation, and determining the linear relation between the logarithm of the concentration of the 2, 5-p-hydroxybenzoic acid or 3, 4-p-hydroxybenzoic acid and the current;
adding a hydroxyl radical trapping agent into a solution to be detected containing hydroxyl radicals, putting the solution into an electrolytic cell, detecting the current corresponding to the 2, 5-p-hydroxybenzoic acid or the 3, 4-p-hydroxybenzoic acid in the sample to be detected through an electrochemical workstation according to the method, substituting the current into a regression equation, and calculating to obtain the concentration of the 2, 5-p-hydroxybenzoic acid or the 3, 4-p-hydroxybenzoic acid in the sample to be detected, namely the concentration of the hydroxyl radicals.
The invention has the advantages that: 1. the hydroxyl radical electrochemical sensor greatly improves the electricitySelectivity for target species in the reaction; 2. g-C 3 N 4 The MWCNTs-COOH mixed material has good conductivity, and provides more specific surface area and active sites for molecular imprinting; 3. the hydroxyl radical electrochemical sensor has the characteristics of quick response, high sensitivity, good stability and the like on the imprinted molecules; 4. the preparation method is simple and is suitable for industrial application and market popularization and application.
Drawings
FIG. 1 is a graph showing the peak response current of example 1 at various concentrations of 2,5-DHAB in differential pulse voltammetry measurements;
FIG. 2 shows lgC in example 1 2,5-DHBA A standard curve versus response current;
FIG. 3 is the peak value of the response current in the differential pulse voltammetry detection of different concentrations of 3,4-DHBA in example 2;
FIG. 4 shows lgC in example 2 3,4-DHBA Standard curve with response current.
Detailed Description
The present invention is further illustrated by the following examples, but the scope of the invention is not limited to the above-described examples.
Example 1
(1) Alternately washing the working electrode of screen printing three-electrode (SPCE) with water and ethanol for 3 times, and placing the working electrode in K containing 0.01mol/L KCl 3 [Fe(CN) 6 ]-K 4 [Fe(CN) 6 ]Solution (containing 0.05mol/L K) 3 [Fe(CN) 6 ]And 0.05mol/L K 4 [Fe(CN) 6 ]Aqueous solution of (2) and circulating voltammetry scanning at a scanning rate of 0.1V/s for 20 circles within a potential range of-1.0 to +1.0V to activate the electrode, and alternately washing the activated working electrode with water and ethanol again and airing for later use;
(2) 100mg of carbon nanotubes are placed in 40mL of mixed acid solution (concentrated H) 2 SO 4 Concentrated HNO 3 In the reaction solution of = 3), performing ultrasonic treatment at 60 ℃ for 4h, washing with water to be neutral, performing suction filtration, and performing vacuum drying on the solid at 60 ℃ to obtain a carboxylated multiwalled carbon nanotube MWCNTs-COOH; respectively taking MWCNTs-COOH and g-C 3 N 4 The solid powders were each 5mg in 10mL of an ethanol solution (H) 2 O:C 2 H 6 O = 3), ultrasonically dispersing for 1h to obtain 1mg/mL of uniformly dispersed mixed solution;
(3) Uniformly dripping 3 μ L of the mixed solution on the surface of the activated working electrode, drying for 10min at 40 deg.C under infrared lamp, and oven drying;
(4) Preparing 10mL of 0.01mol/L chitosan solution, adding 1mL of 0.3mmol/L acrylic acid and 2mL of 0.01mol/L2, 5-DHBA, and performing magnetic stirring at room temperature (the stirring speed is 300 r/min) for 1h of prepolymerization reaction; then adding 1mL of 0.7mmol/L crosslinking agent epichlorohydrin and 1mL of 0.1mmol/L initiator azodiisoheptanenitrile, filling nitrogen, sealing, carrying out polymerization reaction in a water bath at 60 ℃ for 4h, and cooling to room temperature after the reaction is finished to obtain a polymerization solution;
(5) Dripping 3 mu L of polymerization solution cooled to room temperature on g-C 3 N 4 Drying the surface of the MWCNTs-COOH/SPCE electrode for 5min by an infrared lamp at 60 ℃ for later use;
(6) g-C modified by polymerization liquid 3 N 4 the/MWCNTs-COOH/SPCE electrode is placed in 0.1mol/L Na 2 HCO 3 In the solution, i-t method is used for electrolysis for 10min under the potential of 1.3V to remove template molecules, and then the hydroxyl radical electrochemical sensor MIPs/g-C is prepared 3 N 4 /MWCNTs-COOH/SPCE；
(7) Hydroxyl radical electrochemical sensor MIPs/g-C 3 N 4 One end of each MWCNTs-COOH/SPCE is connected to the electrochemical workstation, and the other end is placed in the electrolytic cell respectively, and the concentration range is 1 x 10 -8 ~1×10 -4 The solution containing 2, 5-p-hydroxybenzoic acid is placed still for adsorption and identification for 7min, then transferred to 0.05mol/L phosphate buffer solution with pH of 4, differential pulse voltammetry is used for detection, the potential range of DPV is 0 to 0.6V, the pulse amplitude is 0.05V, the pulse period is 0.2s, the pulse width is 0.05s, the voltage increment is 0.005V, linear fitting is carried out according to the corresponding DPV response current values of different concentrations, the logarithm of the concentration of 2, 5-p-hydroxybenzoic acid is used as an abscissa, the current is used as an ordinate, a standard curve corresponding to 2, 5-p-hydroxybenzoic acid is drawn, and the linear equation is y =0.52lgC 2,5-DHBA +4.09,r =0.996 (see fig. 1, 2);
detection limit of C L =3S b Calculated as,/m,/C L Limit of detection (mol/L), S b Blank standard deviation (. Mu.A), m standard curve slope (. Mu.A/(mol/L)), standard curve slope of 0.52, blank standard deviation obtained by scanning 10 blank samples to take standard deviation of peak current value, 7.8X 10 -10 mol/L, substituting into a formula to calculate a detection limit C L Is 4.5 multiplied by 10 -9 mol/L；
(8) In electrochemical systems, with TiO 2 The electrode is used as an anode, the graphite electrode is used as a cathode, and the electrolyte solution is 0.10mol/L Na 2 SO 4 pH =7.0, electrode sizes are all 3cm × 5cm × 1mm, inter-electrode distance is 5.5cm, and current density is adjusted to 10mA/cm 2 Electrolyzing under the condition with the constant voltage of 7V to generate hydroxyl radicals, detecting the hydroxyl radicals generated in the system by using the hydroxyl radical electrochemical sensor prepared in the step (6) after electrolyzing for 20min, adding salicylic acid serving as a hydroxyl radical scavenger into the electrochemical system, reacting the radicals with the salicylic acid to generate 2,5-DHBA, placing the hydroxyl radical electrochemical sensor prepared in the step (6) in the system for identifying for 10min after reacting for 5min, moving an electrode into a 10mL electrolytic cell, measuring the corresponding current value of the hydroxyl radical electrochemical sensor by using a Differential Pulse Voltammetry (DPV) with the electrolyte solution of 0.05mol/L PBS (pH = 4), wherein the potential range of the DPV is 0-0.6V, the voltage increment is 0.005V, the pulse amplitude is 0.05V, the pulse width is 0.05s, and the pulse period is 0.2s; the corresponding current peak value is 4.8 muA, and C is obtained by substituting the linear equation 2,5-DHBA Is 1.58X 10 -8 mol/L is the concentration of hydroxyl free radicals in the system;
simultaneously, the fluorescence spectrum analysis method is adopted to measure the free radicals in the electrochemical system, and the detection result is that the concentration is 1.62 multiplied by 10 -8 And the mol/L is approximate to the result measured by an infrared spectrum analysis method, so that the feasibility and the accuracy of the sensor for detecting the hydroxyl radicals are shown.
Example 2
(1) The Glassy Carbon Electrode (GCE) was washed with water and ethanol sequentially and alternately 3 times, and the electrode was placed in a K bath containing 0.02mol/L KCl 3 [Fe(CN) 6 ]-K 4 [Fe(CN) 6 ]Solution (containing 0.05mol/L K) 3 [Fe(CN) 6 ]And 0.05mol/L K 4 [Fe(CN) 6 ]The water solution of (2) and circulating voltammetry scanning at a scanning rate of 0.05V/s for 20 circles within a potential range of-1.0 to +1.0V to activate the electrode, and washing the activated electrode with water and ethanol alternately again and drying for later use;
(2) 80mg of carbon nanotubes are placed in 30mL of mixed acid solution (concentrated H) 2 SO 4 Concentrated HNO 3 Performing ultrasonic treatment for 5h at 60 ℃ in the reaction solution of = 2.5), washing the reaction solution with water to be neutral, performing suction filtration, and performing vacuum drying on the solid at 60 ℃ to obtain MWCNTs-COOH; respectively taking MWCNTs-COOH and g-C 3 N 4 The solid powders were dissolved in 10mL of ethanol solution (H) at 10mg each 2 O:C 2 H 6 O = 3), performing ultrasonic treatment for 2h to obtain a uniformly dispersed mixed solution of 2 mg/mL;
(3) Dripping 2 μ L of the mixture on the surface of the activated electrode, and drying under 60 deg.C infrared lamp for 10 min;
(4) Preparing 10mL of 0.03mol/L chitosan, adding 2mL of 0.1mmol/L methacrylic acid and 3mL of 0.03mol/L3, 4-DHBA, and performing magnetic stirring at room temperature (the stirring speed is 400 r/min) for 1.5h of prepolymerization reaction; then adding 2mL of 0.8mmol/L crosslinking agent glutaraldehyde and 2mL of 0.2mmol/L initiator azodiisobutyronitrile, sealing after filling nitrogen, carrying out polymerization reaction for 3h in a water bath at 70 ℃, and cooling to room temperature for later use after the reaction is finished;
(5) Dripping 2 μ L of polymerization solution on g-C 3 N 4 Drying the surface of the electrode/MWCNTs-COOH/GCE for 10min by an infrared lamp at the temperature of 30 ℃ for later use;
(6) Placing a polymerization liquid modified electrode in 0.03mol/L NaH 2 CO 3 Removing the template molecule by chronoamperometry (i-t) at a potential of 1.0V for 20min; thus obtaining the hydroxyl radical electrochemical sensor MIPs/g-C 3 N 4 /MWCNTs-COOH/GCE；
(7) MIPs/g-C 3 N 4 the/MWCNTs-COOH/GCE electrode is used as a working electrode, the platinum electrode is used as a counter electrode, the silver/silver chloride electrode is used as a reference electrode, and the working electrode and the counter electrode are connectedOne end of the electrode and the reference electrode are respectively connected to an electrochemical workstation, and the other ends of the working electrode, the counter electrode and the reference electrode are respectively arranged in the electrolytic cell in the concentration range of 1 multiplied by 10 -8 ~1×10 -5 The solution containing 3, 4-p-hydroxybenzoic acid is statically adsorbed and identified for 10min, then transferred into 0.05mol/L phosphoric acid buffer solution with pH of 4, and detected by using Differential Pulse Voltammetry (DPV), wherein the potential range of the DPV is 0 to 1.0V, the voltage increment is 0.004V, the pulse amplitude is 0.05V, the pulse width is 0.05s, and the period is 0.2s; performing linear fitting according to DPV response current values of different concentrations to obtain a concentration-current relation curve, wherein the linear equation is y =0.47lgC 3,4-DHBA +4.81, r =0.990 (see fig. 3, 4);
detection limit of pass C L = 3S b Calculated as/m, where the slope of the standard curve is 0.47 and the blank standard deviation is obtained by scanning 10 blank samples for the standard deviation of the peak current value, which is 5.01X 10 -10 mol/L, substituting into a formula to calculate a detection limit C L Is 3.2X 10 -9 mol/L；
(8) In pH =2.5 Fenton system, H 2 O 2 Reacting with Fe (II) to generate hydroxyl radical, adding 4-hydroxyphenyl acid (4-HBA) as hydroxyl radical scavenger to react to generate 3,4-DHBA, reacting for 10min, and adding MIPs/g-C 3 N 4 Placing the/MWCNTs-COOH/GCE electrode in the system to be detected for recognition for 12min, moving the electrode into an electrolytic cell, wherein the electrolyte solution is 0.03mol/L of PBS (pH = 4), connecting the working electrode, the counter electrode and the reference electrode to an electrochemical workstation, and performing Differential Pulse Voltammetry (DPV) to measure the corresponding current values, wherein the potential range is 0-1.0V, the voltage increment is 0.004V, the pulse amplitude is 0.05V, the pulse width is 0.05s, and the pulse period is 0.2s; the corresponding current peak value is 6.2 muA, and C is obtained by substituting the linear equation 3,4-DHBA Is 5.89X 10 -11 mol/L is the concentration of hydroxyl free radicals in the system;
simultaneously, the concentration is measured to be 5.92 multiplied by 10 by adopting a fluorescence spectrum analysis method -11 mol/L, the result of the sensor is close to that of infrared spectrum analysis, which indicates that the sensor detects hydroxylFeasibility and accuracy of free radicals.
Claims (8)
1. A preparation method of a hydroxyl radical electrochemical sensor is characterized by comprising the following steps:
(1) Alternately washing the electrode with water and ethanol for 2-4 times, and then putting the electrode in K containing 0.01-0.02mol/L KCl 3 [Fe(CN) 6 ]-K 4 [Fe(CN) 6 ]Carrying out cyclic voltammetry scanning in the solution, alternately washing the activated electrode with water and ethanol again, and airing for later use;
(2) Dispersing a carboxylated multi-walled carbon nanotube and graphite-phase nitrogen carbide in an ethanol solution, and performing ultrasonic dispersion to obtain a uniform mixed solution, wherein the concentration of the carboxylated multi-walled carbon nanotube in water is 0.5-1.0 mg/mL, and the concentration of the graphite-phase nitrogen carbide in water is 0.5-1.0 mg/mL;
(3) The mixed solution is dripped on the surface of the electrode after activation treatment, and the electrode is dried for 10 to 20min under an infrared lamp at the temperature of 30 to 60 ℃ to obtain g-C 3 N 4 MWCNTs-COOH modified electrode;
(4) Adding an imprinting molecular solution and a functional monomer solution into a chitosan solution, and carrying out prepolymerization reaction under the magnetic stirring condition of 300 to 500r/min for 1 to 3h to prepare an imprinting solution; then adding a cross-linking agent solution and an initiator solution, filling nitrogen, sealing, reacting in a water bath at 60-80 ℃ for 2-4 h, and naturally cooling the solution after the reaction to room temperature to prepare a polymer solution;
(5) Dripping the polymerization liquid obtained in the step (4) on g-C 3 N 4 Drying the electrode surface modified by/MWCNTs-COOH for 5-10min under an infrared lamp at the temperature of 30-60 ℃ for later use;
(6) And (5) placing the electrode prepared in the step (5) in an elution solution, and removing template molecules by using a chronoamperometry method to obtain the hydroxyl radical electrochemical sensor.
2. The method for preparing a hydroxyl radical electrochemical sensor according to claim 1, wherein: the electrode in the step (1) is a carbon electrode, a glassy carbon electrode or a gold electrode, K 3 [Fe(CN) 6 ]-K 4 [Fe(CN) 6 ]The solution contains 0.04 to 0.06mol/L K 3 [Fe(CN) 6 ]And K is 0.04 to 0.06mol/L 4 [Fe(CN) 6 ]The scanning potential of the cyclic voltammetry scanning of the aqueous solution is-1.0 to +1.0V, the scanning rate is 0.05 to 0.1V/s, and the number of cycles is 10 to 20 cycles.
3. The method of preparing a hydroxyl radical electrochemical sensor according to claim 1, wherein: the carboxylated multi-walled carbon nanotube is prepared by placing 50 to 100mg of carbon nanotube in 20 to 40mL of mixed acid solution, performing ultrasonic sound at 55 to 65 ℃ for 3 to 5h, then washing with water to be neutral, performing suction filtration, and performing vacuum drying on a solid at 60 ℃, wherein the mixed acid solution is concentrated H 2 SO 4 With concentrated HNO 3 Mixing according to the volume ratio of 2 to 4.
4. The method for preparing a hydroxyl radical electrochemical sensor according to claim 1, wherein: the ethanol solution is prepared by mixing ethanol and water according to the volume ratio of 1: 2 to 4, and the mass ratio of the carboxylated multi-walled carbon nanotube to graphite phase nitrogen carbide is 1.
5. The method for preparing a hydroxyl radical electrochemical sensor according to claim 1, wherein: the concentration of the chitosan solution is 0.01 to 0.05mol/L; the imprinted molecule is 2, 5-p-hydroxybenzoic acid or 3, 4-p-hydroxybenzoic acid, the concentration of the imprinted molecule solution is 0.01 to 0.05mol/L, and the volume ratio of the chitosan solution to the imprinted molecule solution is 5; the functional monomer is one of acrylic acid, methacrylic acid, vinyl benzoic acid, itaconic acid, 2-vinylpyridine and 4-vinylpyridine, the concentration of the functional monomer solution is 0.1 to 0.5mmol/L, and the volume ratio of the chitosan solution to the functional monomer solution is 10; the cross-linking agent is one of ethylene glycol dimethacrylate, divinylbenzene, glutaraldehyde and epichlorohydrin, the concentration of the cross-linking agent solution is 0.7 to 0.9mmol/L, and the volume ratio of the chitosan solution to the cross-linking agent solution is 10 to 1 to 3; the initiator is one of azodiisobutyronitrile and azodiisoheptanenitrile, the concentration of the initiator solution is 0.1 to 0.5mmol/L, and the volume ratio of the chitosan solution to the initiator solution is 10 to 1 to 3.
6. The method for preparing a hydroxyl radical electrochemical sensor according to claim 1, wherein: the elution solution is 0.01 to 0.05mol/L of Na 2 HCO 3 Or NaH 2 CO 3 A solution; the potential of the chronoamperometry is 0.6 to 1.3V, and the elution time is 10 to 20min.
7. Use of the hydroxyl radical electrochemical sensor manufactured by the method for manufacturing a hydroxyl radical electrochemical sensor according to any one of claims 1 to 6 in the detection of hydroxyl radicals.
8. Use according to claim 7, characterized in that: a hydroxyl radical electrochemical sensor is used as a working electrode, one end of each of the working electrode, the counter electrode and the reference electrode is respectively connected to an electrochemical workstation, the other end of each of the working electrode, the counter electrode and the reference electrode is respectively placed in a solution containing 2, 5-p-hydroxybenzoic acid or 3, 4-p-hydroxybenzoic acid with known concentration in an electrolytic cell, after standing, adsorbing and identifying for 7 to 15min, the solution is transferred to a phosphate buffer solution with 0.01 to 0.05mol/L and pH of 4 to 6, and detection is carried out by using a differential pulse voltammetry, wherein during detection, the potential range is 0 to 1.5V, the voltage increment is 0.002 to 0.006V, the pulse amplitude is 0.03 to 0.05V, the pulse width is 0.03 to 0.05s, and the pulse period is 0.1 to 0.3s; recording the current change condition by an electrochemical workstation, drawing a standard curve corresponding to the 2, 5-p-hydroxybenzoic acid or 3, 4-p-hydroxybenzoic acid by taking the logarithm of the concentration of the 2, 5-p-hydroxybenzoic acid or 3, 4-p-hydroxybenzoic acid as an abscissa and the current as an ordinate, obtaining a regression equation, and determining the linear relation between the logarithm of the concentration of the 2, 5-p-hydroxybenzoic acid or 3, 4-p-hydroxybenzoic acid and the current;
adding a hydroxyl radical trapping agent into a solution to be detected containing hydroxyl radicals, putting the solution into an electrolytic cell, detecting the current corresponding to the 2, 5-p-hydroxybenzoic acid or the 3, 4-p-hydroxybenzoic acid in the sample to be detected through an electrochemical workstation according to the method, substituting the current into a regression equation, and calculating to obtain the concentration of the 2, 5-p-hydroxybenzoic acid or the 3, 4-p-hydroxybenzoic acid in the sample to be detected, namely the concentration of the hydroxyl radicals.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210970605.8A CN115201309B (en) | 2022-08-13 | 2022-08-13 | Preparation method and application of hydroxyl radical electrochemical sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210970605.8A CN115201309B (en) | 2022-08-13 | 2022-08-13 | Preparation method and application of hydroxyl radical electrochemical sensor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115201309A true CN115201309A (en) | 2022-10-18 |
| CN115201309B CN115201309B (en) | 2024-01-05 |
Family
ID=83585747
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210970605.8A Active CN115201309B (en) | 2022-08-13 | 2022-08-13 | Preparation method and application of hydroxyl radical electrochemical sensor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115201309B (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104807874A (en) * | 2015-04-23 | 2015-07-29 | 滨州学院 | Preparation and application method of molecular imprinting electrochemical sensor |
| CN108732218A (en) * | 2018-05-21 | 2018-11-02 | 江苏理工学院 | A kind of electrochemical sensor measuring 2,4,6- trichlorophenol, 2,4,6,-Ts and its preparation and application |
| CN110161094A (en) * | 2019-07-04 | 2019-08-23 | 江苏省农业科学院 | The method of free radical is quickly detected based on electrochemical sensor |
| CN113834866A (en) * | 2021-09-15 | 2021-12-24 | 昆明理工大学 | Preparation method and application of molecularly imprinted electrode for electrochemical sensor |
| US20220065808A1 (en) * | 2019-11-25 | 2022-03-03 | Changsha University Of Science And Technology | Method for selective detection of l-tryptophan using formaldehyde as medium |
-
2022
- 2022-08-13 CN CN202210970605.8A patent/CN115201309B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104807874A (en) * | 2015-04-23 | 2015-07-29 | 滨州学院 | Preparation and application method of molecular imprinting electrochemical sensor |
| CN108732218A (en) * | 2018-05-21 | 2018-11-02 | 江苏理工学院 | A kind of electrochemical sensor measuring 2,4,6- trichlorophenol, 2,4,6,-Ts and its preparation and application |
| CN110161094A (en) * | 2019-07-04 | 2019-08-23 | 江苏省农业科学院 | The method of free radical is quickly detected based on electrochemical sensor |
| US20220065808A1 (en) * | 2019-11-25 | 2022-03-03 | Changsha University Of Science And Technology | Method for selective detection of l-tryptophan using formaldehyde as medium |
| CN113834866A (en) * | 2021-09-15 | 2021-12-24 | 昆明理工大学 | Preparation method and application of molecularly imprinted electrode for electrochemical sensor |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115201309B (en) | 2024-01-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Wang et al. | CuCo2O4/N-Doped CNTs loaded with molecularly imprinted polymer for electrochemical sensor: Preparation, characterization and detection of metronidazole | |
| Ragupathy et al. | Electrocatalytic oxidation and determination of ascorbic acid in the presence of dopamine at multiwalled carbon nanotube–silica network–gold nanoparticles based nanohybrid modified electrode | |
| Ryu et al. | Electrochemical sensors for nitrogen species: A review | |
| Su et al. | Electrochemically pretreated screen-printed carbon electrodes for the simultaneous determination of aminophenol isomers | |
| CN104142361B (en) | A kind of protein molecule engram poly ion liquid membrane electrochemical sensor | |
| Hasanzadeh et al. | Poly-dopamine-beta-cyclodextrin: a novel nanobiopolymer towards sensing of some amino acids at physiological pH | |
| CN102253092B (en) | Composite film modified DNA sensor and its preparation method and application in detection of lignin peroxidase (Lip) specific coding gene segment | |
| Cheng et al. | A simple modified electrode based on MIL-53 (Fe) for the highly sensitive detection of hydrogen peroxide and nitrite | |
| CN106290518B (en) | A kind of molecular imprinting electrochemical sensor and preparation method thereof quantitatively detected for salbutamol | |
| CN105776183A (en) | Preparation method of ferrocenyl carbon nanotube composite material and application thereof | |
| CN110346426A (en) | Based on MoS2-The CPO biosensor and its detection NO of AuNPs and ionic liquid2-Application | |
| CN104614425A (en) | Preparation and application of Cu2O hexagram microcrystal composite material adopting functionalized carbon nano tubes as carrier | |
| CN110426434A (en) | A kind of building and its application based on copper porphyrin base covalent organic frame material electrochemical sensor | |
| CN113834866B (en) | Preparation method and application of molecularly imprinted electrode for electrochemical sensor | |
| Huang et al. | Ultrasensitive determination of metronidazole using flower-like cobalt anchored on reduced graphene oxide nanocomposite electrochemical sensor | |
| Rabie et al. | Fabrication of a new electrochemical sensor based on carbon paste electrode modified by silica gel/MWCNTs for the voltammetric determination of salicylic acid in tomato | |
| CN111239215B (en) | Preparation method of phosphorus-doped porous carbon microsphere as niclosamide oxidase sensor | |
| CN115201309B (en) | Preparation method and application of hydroxyl radical electrochemical sensor | |
| CN112326753B (en) | Preparation method and application of triclosan molecular imprinting membrane electrochemical sensor | |
| CN111474222B (en) | Renewable electrochemical sensor for simultaneously detecting epinephrine and uric acid and preparation method and application thereof | |
| Guo et al. | Preparation of molecularly imprinted composites initiated by hemin/graphene hybrid nanosheets and its application in detection of sulfamethoxazole | |
| CN101320036B (en) | Detection method of non-enzyme glucose | |
| CN111257383B (en) | 4-chlorophenol molecularly imprinted electrochemical sensor and preparation method thereof | |
| Huang et al. | Determination of serum glucose using flow injection analysis and highly selective glucose sensor based on composite films | |
| Salimi et al. | Picomolar detection of hydrogen peroxide at glassy carbon electrode modified with NAD+ and single walled carbon nanotubes |
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 |