171 results about "Glassy carbon electrode" patented technology

The invention provides a preparation method of a plate-shaped glassy carbon electrode, which comprises the following steps: curing a resin raw material into a plate-shaped resin block, carbonizing in an inert atmosphere, and respectively introducing a nitrogen source and a boron source for doping operation to obtain a co-doped plate-shaped resin block precursor; placing the co-doped plate-shaped resin block between two porous graphite plates, and carrying out high-temperature treatment to obtain a glassy carbon matrix; and immersing the glassy carbon substrate into the adhesion layer solution to form an adhesion layer, transferring the adhesion layer into a deposition solution which comprises a bismuth-containing solution and a gold-containing solution, forming bismuth-gold nano-dots on the adhesion layer, and washing and drying the bismuth-gold nano-dots to obtain the plate-shaped glassy carbon electrode. Through directional arrangement of crystal orientations, the tantalum carbide coating achieves higher electrical conductivity and thermal conductivity. And the sensitivity and the service life of the plate-shaped glassy carbon electrode are obviously improved and prolonged.

The invention relates to the technical field of electrochemical analysis and detection, in particular to a sensitive detection tert-butylhydroquinone modified glassy carbon electrode, a preparation method and application, the sensitive detection tert-butylhydroquinone modified glassy carbon electrode has high specific surface area and catalytic activity and good conductivity, sensitive detection of tert-butylhydroquinone can be achieved, and the application range is wide. The modified glassy carbon electrode comprises a glassy carbon electrode and a compound coating, the compound coating wraps the surface of the glassy carbon electrode, and the compound coating is composed of graphene oxide and a Ti-based MOF derivative; the preparation method comprises the following steps: (1) preparing MIL-125 (Ti); (2) preparation of TiO2 / NC; (3) preparation of 15% GO (at) TiO2 / NC; (4) preparing a dispersion liquid of the prepared 15% GO-coated TiO2 / NC composite material; (5) manufacturing a modified electrode; the application comprises the following steps: S1, establishing a concentration-electrochemical response signal relationship; and S2, measuring the concentration of the to-be-measured substance.

The invention discloses a composite material modified electrode based on a functionalized single-walled carbon nanotube and application thereof, and belongs to the technical field of electrochemistry, the modified electrode comprises a glassy carbon electrode and a functionalized single-walled carbon nanotube-glucose composite material coating coated on the surface of the glassy carbon electrode; the mass ratio of functionalized single-walled carbon nanotubes to glucose in the coating is (0.2-5): 1, and the functionalized single-walled carbon nanotubes comprise at least one of hydroxylated single-walled carbon nanotubes, carboxylated single-walled carbon nanotubes and aminated single-walled carbon nanotubes, preferably hydroxylated single-walled carbon nanotubes. The composite material modified electrode provided by the invention has a large number of active sites, and by effectively utilizing the synergistic effect of the hydroxylated single-walled carbon nanotubes and glucose, the modified electrode shows excellent selective recognition capability on amino acid enantiomers and also shows good stability; and the method has a good application prospect in quantitative analysis of the amino acid enantiomers.

The invention belongs to the field of new materials, and discloses an electrode-based liposome adriamycin entrapment rate electrochemical detection method. According to the detection method, after a bipolar vertical ordered mesoporous silica film (bp-VMSF) is modified on an electrically activated glassy carbon electrode (p-GCE), separation, enrichment and electrochemical detection are integrated, and rapid and sensitive detection of adriamycin can be realized. The glassy carbon electrode is subjected to electrochemical activation pretreatment under the alkaline condition, bp-VMSF stably grows, the surface of the inner layer close to the p-GCE electrode is negatively charged, and the surface of the outer layer away from the electrode is positively charged. The asymmetric charge configuration enhances the adsorption capacity of positively charged adriamycin molecules on an electrode interface through electrostatic enrichment. The p-GCE adsorbs adriamycin and promotes electron transfer, and is combined with the synergistic enrichment effect of the bp-VMSF double-static nano-channel, so that the electrochemical response performance to adriamycin is jointly improved, a method is provided for rapid detection of the liposome adriamycin encapsulation efficiency, and the p-GCE has a good prospect in evaluation of liposome adriamycin preparations.

The application discloses a kind of glucose oxidase sensors based on modified multi-walled carbon nanotube modification, it is related to glucose oxidase sensor technical field, including the following steps: (1) modified multi-walled carbon nanotube preparation;(2) glassy carbon electrode is carried out surface polishing treatment;(3) obtain modified multi-walled carbon nanotube dispersion;(4) obtain glucose oxidase liquid;(5) glucose glucose oxidase liquid impregnation electrode;(6) using Nafion solution covers electrode;The sensor obtained after the electrode is modified by introducing modified multi-walled carbon nanotube in the application, not only has higher glucose detection sensitivity, but also has excellent stability.

The invention relates to the technical field of detection and identification of fentanyl substances, and discloses a selective quantitative detection method of fentanyl. According to the method, a differential pulse voltammetry (DPV) is used for making a linear relation diagram of a potassium ferricyanide peak current and fentanyl solutions with different concentrations to obtain a standard working curve, a linear equation is obtained through the standard curve, and the detection limit is 1.0 * 10 <-12 > mol.L <-1 >; the molecularly imprinted membrane modified electrode prepared by the invention is used for measuring the peak current of a potassium ferricyanide solution, so that fentanyl molecules can be indirectly and quantitatively analyzed and measured. The method is characterized in that a fentanyl molecularly imprinted membrane is electrically polymerized on the surface of a glassy carbon electrode, m-phenylenediamine is used as a functional monomer, and the selectivity and sensitivity of an electrochemical method for detecting fentanyl are improved. Meanwhile, by taking an adsorption pulse stripping voltammetry (DPASV) as a detection technology, a method capable of rapidly detecting fentanyl molecules in the presence of various drugs is established. The molecularly imprinted membrane electrode disclosed by the invention is simple to prepare, quick in response and good in selectivity and reproducibility, and can be repeatedly used for more than five times.

The application relates to the field of electrochemiluminescence detection, in particular to a preparation method and a detection method of an electrochemiluminescence sensor for detecting di(2-ethylhexyl) phthalate. Technical points are as follows: the electrochemiluminescence aptamer sensor is formed by loading carboxylated ligands on the surface of a Zr-MOF / GDY composite material modified glassy carbon electrode; the Zr-MOF / GDY composite material is formed by electrostatic interaction between Zr-MOF and GDY; and the carboxylated aptamer is an aptamer containing a base sequence of 5'-GGGTAGGGCGGGAAGTTACTGTCTTACTGTC GTA-3'. The recovery effect of DEHP on the ECL signal intensity of the electrochemiluminescence aptamer sensor of the GDY and Zr-MOF composite material is used to realize the detection of DEHP, and the detection method is simple in operation, good in selectivity and high in sensitivity.

The application discloses a method for detecting polychlorinated biphenyl by using an electrochemical aptamer sensor. x The sensor comprises a glassy carbon electrode, a surface of a detection end of the glassy carbon electrode is decorated with an electroactive nanomaterial, the electroactive nanomaterial comprises Ti3C2T 0000001 Nanosheet, a conductive polymer material is embedded in an interlayer structure of the nanosheet and forms a composite nanomaterial, and gold nanoparticles are deposited on a surface of the composite nanomaterial; a capture chain is self-assembled on the electroactive nanomaterial, a specific aptamer probe is combined on the capture chain, a DNA double-stranded structure is formed, and an electroactive label is introduced. In the application, the sensor has the advantages of wide detection range, low detection limit, strong anti-interference ability, good stability and the like, can realize specific detection of polychlorinated biphenyl, has the advantages of low cost, short time consumption, high accuracy, good adaptability and the like, and has important significance for rapid detection of polychlorinated biphenyl.

The application belongs to the technical field of electrochemical analysis and detection, and discloses a preparation method and application of an electrochemiluminescence sensor for specifically detecting trilobatin. The specific operation includes: (1) preparing a composite material of nitrogen-doped carbon quantum dots (N-CDs) and a silver-based metal organic framework (AgMOF) (AgMOF@N-CDs); (2) modifying the AgMOF@N-CDs on a glassy carbon electrode to obtain AgMOF@N-CDs / GCE; and (3) based on a three-electrode system, using the AgMOF@N-CDs / GCE as a working electrode, a platinum wire as an auxiliary electrode, and Ag / AgCl as a reference electrode to construct an electrochemiluminescence sensor for detecting trilobatin. The preparation of the electrochemiluminescence sensor is simple, the analysis speed is relatively fast, the detection range is relatively wide, the sensitivity is relatively high, and the selectivity is relatively good.

The application provides a Cu-MOF@MnCO3 modified glassy carbon electrode and a preparation method thereof and an electrochemical sensor, and the preparation method comprises the following steps: S1, preparing Cu-MOF@MnCO3 powder; S2, polishing, cleaning and drying the surface of a glassy carbon electrode for standby; S3, dissolving the Cu-MOF@MnCO3 powder in DMF, dropwise coating the surface of the glassy carbon electrode treated in the step S2, and heating and drying under an infrared lamp to obtain a Cu-MOF@MnCO3 modified glassy carbon electrode. On the one hand, by combining the signal generated by mercury ions itself and the internal reference signal generated when Cu 2+ and Cu + in the Cu-MOF occur a reduction reaction, the false positive phenomenon is effectively avoided, and the anti-interference, stability and reliability of the electrochemical sensor for detecting mercury ions are improved. On the other hand, the application can further widen the detection range of the electrochemical sensor and reduce the detection limit by amplifying the double signals of MnCO3, and is particularly suitable for detecting trace mercury ions.

The invention discloses a dual-mode detection kit for highly sensitive detection of ERalpha based on HRP-streptavidin. The dual-mode detection kit comprises the following raw materials: a glassy carbon electrode, 1-AP-CNHs, AuNPs, Sh-Apt, MCH, Bio-Ab, and HRP-streptavidin. The invention successfully constructs an electrochemical detection kit for detecting ERalpha with high sensitivity on the basis of the 1-AP-CNHs / AuNPs composite material. According to the invention, due to the redox activity of HRP-streptavidin, the HRP-streptavidin and H2O2 are subjected to redox reaction to generate a current signal; in addition, hydrogen peroxide can be catalyzed to generate. OH free radicals, and the free radicals can oxidize TMB to generate blue products, so that colorimetric reaction is initiated, and ERalpha can be detected more accurately. The electrochemical-colorimetric dual mode of the 3D 1-AP-CNHs / AuNPs composite material and the HRP-streptavidin for high-sensitivity detection of the ERalpha disclosed by the invention greatly improves the detection accuracy. The kit has the advantages of good selectivity, strong stability, high sensitivity, anti-interference performance, environmental protection and the like.

The invention belongs to the technical field of food safety detection, and particularly relates to a histamine molecular imprinting electrochemical sensor based on a carbon-based nano composite material and a preparation method and application of the histamine molecular imprinting electrochemical sensor. Aiming at the problems of poor selectivity, high detection limit or complicated operation and the like of the existing histamine detection technology, a Co3O4 / N-HCS (cobaltosic oxide / nitrogen-doped hollow carbon sphere) composite material is prepared by adopting a solvothermal method, o-phenylenediamine (o-PD) is taken as a functional monomer, a molecularly imprinted polymer membrane (MIP) is constructed on the surface of a glassy carbon electrode (GCE) by adopting an electropolymerization method, and the histamine detection electrode is prepared. The MIP / Co3O4 / N-HCS / GCE sensor with specific recognition sites on histamine is formed. The sensor has high selectivity, high sensitivity and good stability, is simple and convenient to operate and rapid in detection, can efficiently realize accurate detection of histamine in food, and is suitable for safety monitoring scenes of various foods such as fermented food, aquatic products and dairy products.

The application relates to the field of electrochemistry, in particular to a method for determining ion concentration based on a double electrolytic cell ion selective electrode, which comprises the following steps: using a poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) modified glassy carbon electrode or a reduced graphene oxide modified glassy carbon electrode as a working electrode, using a full solid-state ion selective electrode as a reference electrode, and using a platinum wire electrode as a counter electrode; inserting the working electrode and the counter electrode into a test electrolytic cell, inserting the reference electrode into a sample electrolytic cell, connecting the test electrolytic cell and the sample electrolytic cell through Ag / AgCl as a salt bridge, and determining the ion concentration in a to-be-measured solution by adopting a constant potential coulomb analysis method. The technical scheme of the application can minimize the current response time while ensuring the accuracy of ion concentration determination, realizes rapid measurement of ion concentration, and can be applied to detection of ion concentration in human serum.

The invention discloses a chitosan modified ferroferric oxide / carboxylated multi-walled carbon nanotube-based molecularly imprinted electrochemical sensor as well as a preparation method and application thereof, and relates to the technical field of electrochemical sensing. The invention aims to solve the problems that the existing method for detecting carbendazim is complicated to operate and high in cost and the traditional sensor is poor in selectivity. The invention discloses a molecularly imprinted electrochemical sensor based on chitosan modified ferroferric oxide / carboxylated multi-walled carbon nanotubes. The molecularly imprinted electrochemical sensor comprises a glassy carbon electrode, and a molecularly imprinted polymer and CS-Fe3O4-CMWCNTs which are modified on the surface of the glassy carbon electrode, the molecularly imprinted polymer is prepared by taking carbendazim as a template molecule, methacrylic acid as a functional monomer, ethylene glycol dimethacrylate as a cross-linking agent and azodiisobutyronitrile as an initiator. The molecularly imprinted electrochemical sensor is applied to detection of carbendazim.

This invention discloses a functionalized biomodified electrode for rapid pathogen detection and its preparation method, relating to the fields of biosensing and electrochemical detection technology. It includes a glassy carbon electrode substrate, the surface of which is sequentially modified with a reduced graphene oxide layer, an electropolymerized polydopamine film, and an electrodeposited gold nanoparticle layer, forming a composite nanomaterial modified electrode. Antibodies are captured and fixed to the electrode surface through covalent interactions. This functionalized biomodified electrode for rapid pathogen detection and its preparation method, using the same electrochemical workstation, first electropolymerizes dopamine to form a film and then electrodeposits gold nanoparticles. This allows for precise control of film thickness, gold particle size, and coverage density by parameters such as polymerization potential, scan cycles, deposition potential, and deposition time. This avoids batch-to-batch fluctuations caused by dissolved oxygen and solution disturbances in traditional chemical methods, reducing the relative standard deviation of peak current detection from different batches of electrodes from 18.7% to 4.2%–4.5%.

The invention discloses a method for high-value utilization of micro mineral powder solid waste, which comprises the following steps of: naturally air-drying micro mineral powder, grinding and sieving to obtain a micro mineral powder raw material; uniformly mixing the micro mineral powder with biomass in different proportions, performing high-temperature oxygen-limited pyrolysis in a muffle furnace, and modifying by phosphoric acid, citric acid, CaCl2 and the like to obtain a micro mineral powder / biomass nano composite material; dispersing the micro mineral powder / biomass nano composite material and chitosan in water, and performing ultrasonic compounding for a period of time to obtain a chitosan / micro mineral powder / biomass nano composite material mixed solution; dispensing the mixed solution on the surface of a glassy carbon electrode to prepare a chemically modified electrode; the electrode is used for detecting dopamine and nitrite substances. The micro mineral powder nano material with high electrocatalytic activity can be prepared and can be used as an electrode material in the fields of batteries, electrochemical sensors, capacitors and the like.

The application relates to a chromium ion form analysis method based on electrochemical and Raman bimodal detection signals. Au-Ag Janus NPs solution is added dropwise on the surface of a glassy carbon electrode, the DPV signal value and the Raman signal value of a to-be-detected solution containing Cr 6+ and Cr 3+ are detected, the concentration of Cr 6+ in the to-be-detected solution is obtained, Cr 6+ in the to-be-detected solution containing Cr 3+ and Cr 3+ is oxidized into Cr 6+ under the conditions of strong alkalinity and heating by using potassium permanganate, then a reducing agent is added to obtain a mixed solution, the concentration of Cr 6+ in the mixed solution is detected through the DPV signal value and the Raman signal value, Cr 3+ is completely converted into Cr 6+ , the total chromium concentration is measured, finally the concentration of Cr 3+ is obtained by subtraction, and finally the chromium ion form analysis is realized. The method improves the accuracy and efficiency of Cr ion form detection, and is suitable for rapid analysis of Cr ion forms in environment and biological samples.

The application belongs to the field of thin film transistor sensing and biomarker detection, and relates to an enzyme-free liquid gate thin film transistor sensor for detecting a myocardial injury marker, which comprises a source electrode, a drain electrode and a functionalized gate electrode, the source electrode and the drain electrode are noble metal interdigital electrodes deposited on the surface of a SnO2 thin film, the interdigital array region is connected through the SnO2 thin film, that is, a channel region; the functionalized gate electrode is formed by sequentially constructing a gold nanoparticle layer, a polydopamine connecting layer and a specific aptamer covalent fixing layer on the surface of a glassy carbon electrode, and serves as a biological recognition interface; the myocardial injury marker is detected by recognizing the threshold voltage offset generated by the myocardial injury marker. In view of the super-sensitivity detection requirement of a clinical myocardial injury marker, the sensor constructed by the application is used for detecting the myocardial injury marker, has a super-wide detection range (0.001~1000 ng mL ‑1 ) and super-high sensitivity, exhibits an extremely low detection limit (as low as 1 pg mL ‑1 ) and good selectivity, and is especially suitable for precise detection of trace myocardial injury markers.

The invention discloses an enzyme biosensor for rapid detection of organophosphorus pesticide dimethoate as well as preparation and application of the enzyme biosensor, and relates to the field of electrochemical sensors. The method comprises the following steps: preparing GR / GCE, preparing AuNPs / GR / GCE, and preparing AChE / AuNPs / GR / GCE. Graphene and gold nanoparticles are compounded to form AuNPs / GR / GCE, the electrochemical impedance of the glassy carbon electrode is remarkably reduced, the effective specific surface area of the glassy carbon electrode is increased, the electron transfer rate of the surface of the glassy carbon electrode is increased, rich binding sites are provided for immobilization of enzyme molecules, the stability of enzyme is improved, and degradation or inactivation of the enzyme in the using process is reduced; acetylcholine esterase is used as a recognition probe, AChE / AuNPs / GR / GCE is constructed on AuNPs / GR / GCE in a self-assembly mode, dimethoate can prevent acetyl thiocholine iodide from being hydrolyzed to generate thiocholine, electrochemical response signals are reduced, and the dimethoate has good electrochemical response signals, so that the organophosphorus pesticide dimethoate residue is rapidly, accurately and safely screened on site.

The invention discloses a modified electrode, a preparation method of the modified electrode and application of the modified electrode in caffeic acid detection, and relates to the technical field of electrochemical detection.The preparation method of the electrode comprises the following steps that firstly, an Au nano solution is prepared; 2, preparing a polyaniline hollow nanotube suspension liquid; 3, pretreating the glassy carbon electrode; and 4, modifying the glassy carbon electrode by using gold nanoparticle-polyaniline. The modified electrode has the advantages of being simple in preparation process, high in detection stability and high in detection sensitivity, the application prospect is wide, and good research, development and application values are achieved.

The invention discloses a preparation method of an AgNPs (at) ZIF-8 / CNHs / GCE electrode, an electrochemical sensor and application of the electrochemical sensor in bisphenol A. The preparation method comprises the following steps: sequentially polishing a glassy carbon electrode GCE to be smooth by using aluminum oxide powder with different particle sizes, sequentially carrying out ultrasonic treatment in ethanol and pure water to remove surface residues, and airing at room temperature; the preparation method comprises the following steps: respectively dissolving zinc acetate dihydrate and 2-methylimidazole in a methanol solution to respectively obtain a clear solution A and a clear solution B, pouring the solution B into the stirred solution A, and then centrifuging, washing and drying to obtain ZIF-8 powder; the preparation method comprises the following steps: dissolving AgNO3 in a mixed solution of water and ethanol, stirring, then adding ZIF-8 powder and CNHs powder into the AgNO3 solution, continuously stirring, and then centrifuging, washing and drying to obtain AgNPs (at) ZIF-8 / CNHs powder; agNPs (at) ZIF-8 / CNHs powder is dispersed in pure water, and an AgNPs (at) ZIF-8 / CNHs solution is obtained; and dropwise adding the AgNPs (at) ZIF-8 / CNHs solution onto a glassy carbon electrode GCE, and airing to obtain the AgNPs (at) ZIF-8 / CNHs / GCE electrode.

The application belongs to the technical field of electrochemical analysis and detection, and discloses a molecular imprinting electrochemiluminescence sensor, a preparation method thereof and application of the sensor in selective detection of trilobatin. The operation comprises the following steps: (1) a prepared g-C3N4@NiMOF composite material is modified on the surface of a glassy carbon electrode; (2) the g-C3N4@NiMOF / GCE is placed in a phosphate buffer solution containing o-phenylenediamine and TRI, and o-PD and TRI are electropolymerized on the electrode surface through cyclic voltammetry in a three-electrode system to obtain MIP-p(o-PD)-TRI / g-C3N4@NiMOF / GCE; and (3) TRI in the polymerization film is eluted to form a specific imprinting cavity, and a MIP-p(o-PD) / g-C3N4@NiMOF / GCE sensor is obtained. The molecular imprinting electrochemiluminescence sensor has the advantages of simple operation, fast analysis speed, good selectivity and high sensitivity in the detection of TRI.

The present application is directed to the problem of small specific surface area, low active site density and limited active material loading of the electrode surface of the conventional glassy carbon electrode, and provides a three-dimensional flexible carbon-based material and a preparation method thereof, comprising: weighing SEBS and adding it into a toluene solution to stir into a uniform solution; taking carbon nanotubes, graphene powder, graphite powder, sodium bicarbonate and white sugar and stirring uniformly; taking the toluene solution of SEBS, adding it into the mixed powder, adding toluene solution, stirring until mixed uniformly to obtain carbon slurry; taking the carbon slurry, transferring it into a corresponding mold for shaping, transferring the shaped slurry into anhydrous ethanol for soaking to solidify the carbon slurry; after the solidified carbon slurry material is dried, it is immersed into a hydrochloric acid solution to obtain a three-dimensional carbon-based material with a porous structure. The present application synthesizes a three-dimensional, porous, flexible and conductive carbon-based material, which is applied to a biological sensing electrode or a biological fuel cell to effectively increase the specific surface area and active material attachment sites of the electrode.

This invention relates to the field of electrochemical detection technology for vitamin E, specifically to an electrochemical detection device and method for vitamin E. The method includes: utilizing a detection system composed of a glassy carbon electrode, a saturated calomel electrode, and a platinum wire electrode; performing a series of optimizations and screenings to determine the SWV electrochemical detection method; and electrode pretreatment: using 0.05 μm alumina powder to perform circular polishing on the glassy carbon electrode in both directions for 3-4 minutes, followed by ultrasonic cleaning with anhydrous ethanol and pure water for three minutes each time. Finally, the electrode is scanned using the SWV method in a prepared buffer solution until it stabilizes. The beneficial effects are: this invention is convenient and simple to operate, has a simple formulation that greatly optimizes the detectable limit, has low manufacturing cost and is readily available, and requires no electrode modification; the lowest detectable concentration is far below the minimum normal range of vitamin E in human blood.

The invention relates to a chromium ion morphology analysis method based on electrochemical and Raman bimodal detection signals. Dropwise adding an Au-Ag Janus NPs solution on the surface of the glassy carbon electrode, and detecting a DPV signal value and a Raman signal value of a to-be-detected solution containing Cr < 6 + > and Cr < 3 + > to obtain the concentration of Cr < 6 + > in the to-be-detected solution; the method comprises the following steps: oxidizing Cr < 3 + > in a to-be-detected solution containing Cr < 6 + > and Cr < 3 + > into Cr < 6 + > by using potassium permanganate under the conditions of strong alkalinity and heating; then adding a reducing agent to obtain a mixed solution; detecting the Cr < 6 + > concentration of the mixed solution according to the DPV signal value and the Raman signal value; and completely converting Cr < 3 + > into Cr < 6 + >, measuring the concentration of total chromium, and finally subtracting to obtain the concentration of Cr < 3 + >, thereby finally realizing chromium ion morphological analysis. The method provided by the invention improves the accuracy and efficiency of Cr ion morphology detection, and is suitable for rapid analysis of Cr ion morphology in environmental and biological samples.

The application belongs to the technical field of electrochemiluminescence detection, and discloses a preparation method of a thiamethoxam electrochemiluminescence sensor based on Fe / Zn-MOF@C-dots sensitization, which comprises the following steps: C-dots preparation, Fe / Zn-MOF preparation, Fe / Zn-MOF@C-dots preparation, modification of Fe / Zn-MOF@C-dots to the surface of a glassy carbon electrode through chitosan, then combination of a single strand of thiamethoxam DNA aptamer to the surface of the composite nanomaterial as a recognition element through a crosslinking agent, construction of a biosensor capable of recognizing thiamethoxam, electrochemical method detection and electrochemiluminescence method detection. The Fe / Zn-MOF@C-dots composite material is used as an electrochemiluminescence reagent for the first time, and compared with C-dots, the electrochemiluminescence signal of the Fe / Zn-MOF@C-dots is significantly enhanced; at the same time, the sensor uses DNA aptamer as a specific recognition element of the target molecule thiamethoxam, and effectively improves the selection performance of the sensor. The sensor shows significant repeatability, good selectivity and long-term stability, and can be used as an effective means for detecting thiamethoxam residues in agricultural products and origin environments.

The invention discloses a high-performance biosensor based on a g-C3N4 / TiO2 heterojunction as well as a preparation method and application of the high-performance biosensor, and belongs to the technical field of biosensing and food safety detection. The sensor is constructed by taking a glassy carbon electrode as a substrate and sequentially modifying a g-C3N4 / TiO2 heterojunction composite material and diamine oxidase (DAO). The g-C3N4 / TiO2 heterojunction is prepared through a one-step calcination method, a type II p-n junction structure is formed, photo-generated charge separation and interface electron transfer are effectively promoted, and the conductivity, catalytic activity and enzyme immobilization capacity of the electrode are remarkably improved. The invention discloses a synergistic mechanism of heterojunction interface enhanced histamine selective adsorption and catalytic reaction through density functional theory calculation. The sensor shows excellent detection performance on histamine: the linearity is good in a range of 0.05-10 mM, and the detection limit is as low as 0.075 M; the selectivity is still higher than 93% in the presence of an interferent with ten times of concentration; when the method is applied to detection of actual samples of beef, mutton, fish and chicken, the adding standard recovery rate is 93.60%-101.8%, and the relative standard deviation is smaller than 5%. The sensor has the advantages of high sensitivity, good selectivity, strong anti-interference capability, good reproducibility and the like, and a reliable new method is provided for rapid and accurate screening of histamine in food.

Disclosed herein is a battery for generating hydrogen. The battery comprises a working electrode; a reference electrode; a counter electrode; the electrolyte is sulfuric acid with the concentration of about 0.5 M; wherein the working electrode is prepared by coating a layer of ink on a glassy carbon electrode and air-drying the glassy carbon electrode; and the ink is prepared by mixing the TMD composite material decorated by platinum nanoparticles with a solution to form a mixture and carrying out ultrasonic treatment on the mixture, and the solution is composed of water, ethanol and 5% sulfonated tetrafluoroethylidene fluorinated polymer-copolymer dispersion according to a volume ratio of 4: 1: 0.1.

The invention belongs to the technical field of metal ion detection, and discloses a chitosan-nano titanium dioxide composite modified electrode as well as a preparation method and application thereof, which are used for solving the technical problems of tedious preparation process, high detection limit and narrow matrix applicability of the modified electrode in the existing heavy metal ion detection technology. The preparation method comprises the following steps: adding chitosan into a glacial acetic acid solution to obtain a chitosan solution; then adding a carbon material and nano titanium dioxide, and uniformly dispersing to obtain a composite modification solution; and dispensing the composite modification liquid on the surface of a pretreated glassy carbon electrode, and performing vacuum drying to obtain the chitosan-nano titanium dioxide composite modified electrode. The preparation method of the composite modified electrode is simple; when being used for metal ion detection, the fluorescent probe can detect Pb2, Hg2 and Cr3 at the same time, and has the advantages of low detection limit, wide linear detection range span and high sensitivity.

The application discloses a method for preparing hydrogen peroxide through electrocatalytic oxygen reduction, wherein an oligolayer graphene wrapped Ni catalyst is dispersed in a solvent and dropped on the surface of a rotating ring disc glassy carbon electrode, and after drying, the catalyst is used as a working electrode for preparing hydrogen peroxide through electrocatalytic oxygen reduction. The application adopts the oligolayer graphene wrapped Ni catalyst to produce hydrogen peroxide through electrocatalytic oxygen reduction, the catalyst is simple to prepare and easy to implement, and raw materials are cheap and easy to obtain. The obtained oligolayer graphene wrapped Ni catalyst has excellent selectivity and stability in the process of preparing hydrogen peroxide through electrocatalytic oxygen reduction in an acidic environment, and has important significance for industrialization of electrochemical preparation of hydrogen peroxide in an acidic environment.