35 results about "Chronoamperometry" patented technology

This invention discloses a time-division multiplexed dual-mode monitoring sensor for blood glucose and implanted wound infection, and its monitoring method. The sensor includes an electrically connected sensing unit and a detection unit. The sensing unit includes a three-electrode system of sensing electrodes, and the detection unit includes a chronoamperometry circuit for blood glucose measurement, an open-circuit voltage method circuit for wound pH measurement, a switching circuit, and a control module. The control module regulates the switching circuit, enabling the sensor to alternately perform blood glucose and implanted wound pH measurements in a time-division multiplexed manner. Based on the pH measurement data, the blood glucose measurement results can be dynamically calibrated, and an alarm is triggered when the wound infection level measured by the pH measurement data exceeds a preset threshold. This invention optimizes the combination relationship of the three-electrode system and the timing control of the detection modes, achieving simultaneous detection of two indicators without adding additional electrodes. This not only improves detection accuracy and wearing comfort but also simplifies the device structure and reduces costs, showing great application potential.

The application relates to the field of electrochemical analysis methods, and particularly discloses a preparation method of an electrode capable of simultaneously detecting amaranth, carmine and indigo and application of the electrode; the electrode preparation method is as follows: firstly, Fe / Co Prussian blue seed modified carbon fiber paper is prepared through a chemical deposition method; secondly, the Fe / Co Prussian blue seed modified carbon fiber paper is subjected to a hydrothermal reaction to prepare hollow cubic octahedral Fe / Co Prussian blue nanomaterial modified carbon fiber paper electrode; finally, the hollow cubic octahedral Fe / Co oxide nanomaterial modified carbon fiber paper electrode (CoFe2O4@CFP) is obtained through calcination. The CoFe2O4@CFP electrode is used as a working electrode, and the content of the three pigments, i.e. amaranth, carmine and indigo, in a sample to be detected can be simultaneously detected by adopting a differential pulse voltammetry method combined with a chronoamperometry method. Compared with other methods, the method has the advantages of simple preparation, rapid detection, wide application in simultaneous determination of amaranth, carmine and indigo in actual samples such as candies, tap water and beverages, high detection sensitivity, wide detection range and great practical application potential.

This invention belongs to the field of electrochemical testing technology and discloses a dual-plate portable electrochemical testing system, including an upper plate, a lower plate, an electrochemical biosensor electrode converter, and a mobile terminal APP. The invention adopts an upper and lower plate structure, separating the data programming surface and the sensor interface surface, facilitating the replacement and upgrading of computing resources and the analog front-end separately. The invention hierarchically lays out the three-electrode interface analog circuit and the communication control circuit, and separates the power supply for digital and analog power supplies, which helps reduce mutual interference between the sensor's analog signal lines and digital communication signal lines, improving the stability of electrochemical testing. This invention enables wireless interaction via a mobile terminal and can be portablely powered by an external terminal device, offering flexible usage and facilitating on-site deployment and mobile testing. This invention supports multiple testing modes, including cyclic voltammetry, chronoamperometry, and differential pulse voltammetry, adapting to different electrochemical testing needs.

Provided is a transition metal-doped nickel oxyhydroxide catalyst, its preparation method, and its application in seawater electrolysis for hydrogen production. The method includes: (1) constructing a three-electrode system and using a chronoamperometry or chronopotentiometry method to electrodeposit a precatalyst onto a conductive substrate from a mixed metal salt solution containing nickel, iron, and at least one other transition metal salt such as cobalt or chromium; and (2) using the precatalyst-loaded substrate as a working electrode in an alkaline solution and applying a constant current to perform an in-situ conversion, thereby forming the final transition metal-doped nickel oxyhydroxide catalyst. The resulting catalyst exhibits high catalytic activity, high selectivity for oxygen evolution, and exceptional long-term stability under high current densities, making it highly suitable for direct seawater electrolysis systems,

This invention relates to the field of electrocatalytic hydrogenation, specifically to a method for electrocatalytic NADH regeneration. The method includes the following steps: using copper foam as the anode, platinum wire as the cathode, and KOH solution as the electrolyte, in-situ oxidation is performed using a chronopotential method; the nanowires are then washed with water and ethanol, vacuum dried, and calcined in a tube furnace to obtain CuO nanowires; using the CuO nanowires as the cathode and platinum wire as the anode, the CuO nanowires are in-situ reduced using a chronoamperometry method to obtain Cu nanowires; thioacetamide and acetic acid are added to a copper sulfate solution, stirred to obtain a reaction solution; the Cu nanowires and reaction solution are added to a chemical bath deposition container, heated, washed, and dried to obtain Cu... x S nanowires; electrocatalytic NAD in an inert gas atmosphere + Regeneration of 1,4-NADH; in S4, the electrocatalytic potential is -1.1 to -1.25 V vs. Ag / AgCl. This method enables efficient and selective hydrogenation at the 1,4 position to generate NADH.

The invention relates to a preparation method of a Co3O4 nanowire spherical array coupled bimetallic hydroxide electrode material, and belongs to the technical field of electrocatalyst preparation. The preparation method comprises the following steps: pre-treating carbon cloth with a piranha solution, preparing a precursor solution from Co (NO3) 2.6 H2O, NH4F and Co (NH2) 2, preparing a Co3O4 nanowire by using a hydrothermal method in combination with an annealing process, preparing a bimetallic solution, and carrying out electro-deposition to obtain the Co3O4 nanowire coupled bimetallic hydroxide electrode material. A high-binding-force and high-crystallinity Co3O4 nanowire structure is constructed by pretreating carbon cloth, accurately controlling the molar ratio of Co < 2 + > to F <-> to urea in a precursor solution and combining a hydrothermal method with an annealing process, meanwhile, step-by-step electro-deposition is carried out in the range of-1.2 V to 0.2 V by adopting a chronoamperometry, each step stays for 5 seconds, and codeposition kinetics of Ni < 2 + > and Fe < 3 + >, Co < 2 + >, Zn < 2 + > or Cu < 2 + > is accurately controlled; through collaborative optimization of the means, the catalytic activity, the structural stability and the charge transfer efficiency of the composite electrode material are remarkably improved.

The invention provides a method for rapidly detecting pesticide residues in fruits and vegetables, and belongs to the field of pesticide analysis and detection. The method comprises the following steps: mixing a copper nanoparticle / reduced graphene oxide / chitosan composite material, acetylcholin esterase, choline oxidase and a cross-linking agent glutaraldehyde solution for reaction to obtain a double-enzyme functionalized nano composite material; dispensing a chitosan solution on the surface of a working electrode of a screen-printed electrode, drying to form a film, and covalently modifying the surface of the electrode with the bienzyme functionalized nano composite material through a cross-linking agent glutaraldehyde to obtain a sensing electrode; according to the method, acetylcholine is taken as a substrate, a sensing electrode is used, a chronoamperometry is adopted, inhibition ratios of pesticide standard substance solutions with different known concentrations to electrode response current are detected, and a standard curve between the pesticide concentration and the current inhibition ratio is established; and calculating the pesticide residue concentration in the fruit and vegetable sample to be detected according to the current inhibition ratio of the liquid to be detected and the standard curve. Therefore, the sensitivity and accuracy of pesticide residue detection in fruits and vegetables are improved.

The invention relates to the technical field of electrical property testing of materials, in particular to a method for rapidly and quantitatively detecting the conductivity of photocuring conductive hydrogel, which comprises the following steps: step S1, pretreatment of a curing container; s2, injecting a hydrogel solution, curing and detecting the conductivity; placing the curing container on a detection base; an electrolyte solution and deionized water are dropwise added into the two liquid storage tanks respectively, the head end and the tail end of the curing container are soaked in the electrolyte solution and the deionized water respectively, then a detection device is used, a chronoamperometry method is adopted for measuring current, and the conductivity is obtained through calculation; the method is high in detection efficiency, rapid and quantitative detection of conductivity is realized, real conductivity detection data can be obtained, the accuracy and reliability of a detection result are ensured, and the problems that an existing detection method is long in detection time consumption, low in detection efficiency, low in conductivity detection data authenticity and poor in detection accuracy are solved. And the accuracy and the reliability of a detection result cannot be ensured.

The invention relates to a preparation method and application of a phenanthroline-based Schiff base derivative, a Schiff base substance is synthesized by amine-aldehyde condensation reaction between 1, 10-phenanthroline-2, 9-dicarboxaldehyde (PDL) and thionine (Thi), the PDL has an excellent carbon skeleton, the Thi has an excellent electron transport performance, and the Schiff base substance can be used for preparing the phenanthroline-based Schiff base derivative. The two are combined to synthesize a novel electron mediator (PT) with good electron transmission performance and high stability. The preparation method is simple, efficient and low in cost, the current in the solution to be detected is tested through a chronoamperometry, and the concentration of the catechol in the solution to be detected is obtained according to the linear relation between the concentration of the catechol and the current. According to the invention, PT is used as an electron transporter, the composite material is formed by loading laccase through PT to serve as a catechol electrochemical sensing catalyst, the composite material shows excellent electrochemical sensing performance, catechol is detected under the constant overpotential condition of 0.23 V (vs.SCE), the lowest detection lower limit is 0.531 [mu] M, and the linear response range is 1-1000 [mu] M.

The invention discloses a nickel cobalt phosphide electrochemical low-reduction-potential sensitive electrode based on a nitrite catalytic reduction mechanism, and a preparation method and application thereof, and belongs to the technical field of electrochemical sensing. The preparation method comprises the following steps: firstly, pretreating carbon cloth by adopting a strong acid mixed solution to enhance the hydrophilicity of the carbon cloth, cleaning for later use, and then dissolving a cobalt source, a nickel source and phosphate in deionized water according to a specific proportion to prepare an electro-deposition solution; and then, taking the pretreated carbon cloth as a working electrode, and performing electrodeposition on the surface of the working electrode by adopting a chronoamperometry to form a cobalt nickel phosphide nanoflower structure, so as to prepare the sensitive electrode. When the electrode is applied to nitrite detection, the electrode shows excellent electrocatalytic reduction activity in a system formed by a mercury / mercuric oxide reference electrode and a platinum counter electrode. The electrode prepared by the invention can realize high-sensitivity, rapid and low-potential detection of nitrite ions, and effectively solves the problems of insufficient sensitivity, high oxidation overpotential, poor selectivity and the like of an electrochemical nitrite sensor.

The application belongs to the technical field of electrochemical energy storage, and relates to electrochemically activated vanadium diboride, a preparation method thereof and application of the vanadium diboride in a water-based energy storage positive electrode material. The method comprises the following steps: assembling a vanadium diboride positive electrode, a separator, a negative electrode and a water-based electrolyte into an energy storage system; and activating by using a chronocoulometry method, a repeated cyclic voltammetry method, a chronopotentiometry method or a multiple constant current charge-discharge cycle method to obtain an in-situ electrochemically activated vanadium diboride positive electrode material. The electrochemically activated vanadium diboride positive electrode is applied to a Zn 2+ , Li + , NH4 + , Mg 2+ , etc. water-based energy storage system, and exhibits high electrochemical activity. For example, a zinc ion battery assembled at a current density of 0.1 A / g has a specific capacity of 331 mAh / g. The electrochemically activated vanadium diboride water-based energy storage positive electrode material provided by the application has high specific capacity and long cycle life, is low in preparation cost, simple in preparation process and suitable for large-scale industrial production.

This invention discloses a method for preparing a PdCu / CP electrode and its application, as well as an electrocatalytic hydrogenation-aldehyde oxidation battery. The preparation involves using a mixed aqueous solution of palladium and copper sources as the electrodeposition solution, and carbon paper as the working electrode. Electrochemical deposition is performed in a three-electrode system using a chronoamperometry method. The deposition potential is -0.6 to -0.1 V vs. Ag / AgCl, and the deposition time is 10-30 min. Pd and Cu are loaded onto the carbon paper in an alloy form to obtain the PdCu / CP electrode. The molar ratio of Pd in ​​the palladium source to Cu in the copper source in the electrodeposition solution is 1:1.2-1.5. The PdCu / CP electrode prepared by this invention can simultaneously serve as both cathode and anode for electrocatalytic hydrogenation and aldehyde oxidation. Furthermore, it can efficiently generate high-value chemicals simultaneously at both the anode and cathode without external power, effectively reducing energy consumption. The high synthesis efficiency of high-value-added chemicals demonstrates significant application potential.

Disclosed is a method for preparing an electrochemically activated electrode for electrochemical reduction reactions, the electrode comprising at least one catalytic material based on at least one group VIB metal supported on an electrically conductive support, the method consisting in carrying out an electrochemical treatment on an electrode comprising at least one catalytic material based on at least one group VIB metal supported on an electrically conductive support. The electrochemical treatment, which is carried out by cyclic voltammetry (CV) or chronoamperometry (CA), consists of a step of oxidation under specific conditions.

Methods and apparatus for electrochemical analysis of water include acid cleaning a quartz crystal microbalance (QCM), stabilizing a QCM in analyte solution, and analyzing the solution by chronoamperometry and measuring a frequency shift of the QCM. The method may further include cleaning the QCM in an acid solution prior to stabilizing the QCM in analyte solution. The apparatus may provide at least semi-automated electrochemical analysis of water including determining a concentration of an analyte in a water sample, and communicating the concentration of the analyte over a network. The analyte may be manganese.

The invention relates to the technical field of catalyst preparation, in particular to a method and a system for preparing a catalyst for preparing glycollic acid through efficient electrocatalytic oxidation of PET (polyethylene terephthalate). The method comprises the following steps: ultrasonically cleaning foamed nickel to obtain ultrasonically cleaned foamed nickel, preparing a hydrothermal solution, performing hydrothermal reaction on the hydrothermal solution to obtain an initial intermediate, and cleaning and drying the initial intermediate to obtain the catalyst for preparing glycollic acid through efficient electrocatalytic oxidation of PET. The method comprises the following steps: obtaining an intermediate, shearing an intermediate sheet, preparing an electro-deposition liquid, constructing a three-electrode system, depositing a working electrode to obtain deposited Pd particles, slowly flushing the deposited Pd particles to obtain clean deposited Pd particles, testing the catalyst by a linear voltammetry scanning method to obtain the catalytic activity of the catalyst, and performing a chronoamperometric test on the catalyst to obtain the catalytic activity of the catalyst. The selectivity test is performed on the catalyst, so that the selectivity of the catalyst is excellent, and the preparation of the catalyst for preparing glycollic acid through high-efficiency electrocatalytic oxidation of PET is completed. The use amount of precious metal can be reduced on the premise of ensuring the catalytic performance.

The invention discloses a MoS2 electrochemical sensor as well as a preparation method and application thereof, and belongs to the technical field of detection of residual quantity of harmful substances. The MoS2 / CC electrode material is successfully constructed on the carbon cloth substrate by adopting the electro-deposition method and combining high-temperature calcination, the MoS2 film can be directly grown on the surface of the electrode through the electro-deposition method by adjusting parameters such as voltage and current density, accurate control of thickness and morphology is realized, a high-temperature complex process of a chemical vapor deposition (CVD) method is avoided, energy consumption is remarkably reduced, and the method is suitable for industrial production. And the adhesive is prevented from covering the active sites of the catalyst. Compared with a hydrothermal method, the product is more uniform, and the cost is lower. A chronoamperometry (i-t) is adopted for deposition, the problem of reduction corrosion of a potential circulation method (CV) can be avoided, and meanwhile the deposition rate is remarkably higher than that of cathodic electrolysis (CE). The prepared sensor shows excellent electrochemical sensing performance on H2O2 by virtue of the excellent characteristics of the transition metal sulfide MoS2.

The invention discloses a time division multiplexing type blood sugar and implanted wound infection dual-mode monitoring sensor and a monitoring method thereof. The sensor comprises a sensing unit and a detection unit which are electrically connected, the sensing unit comprises a sensing electrode of a three-electrode system, and the detection unit comprises a timing current method circuit for blood glucose measurement, an open-circuit voltage method circuit for wound pH measurement, a switching circuit and a control module. The control module regulates and controls the switching circuit, so that the sensor alternately performs blood glucose measurement and implantation wound pH measurement in a time division multiplexing mode. The blood glucose measurement result can be dynamically calibrated based on the pH measurement data, and early warning is triggered when the wound infection degree measured by the pH measurement data exceeds a preset threshold value. By optimizing the combination relation of the three-electrode system and the sequential control of the detection mode, the synchronous detection of two indexes is realized under the condition of not adding extra electrodes, so that the detection accuracy and the wearing comfort are improved, the equipment structure is simplified, the cost is reduced, and the application prospect is very good.

This invention provides a method and apparatus for perioperative fibrinogen detection, comprising the following steps: S1, modifying the working electrode surface of a screen-printed electrode with antibody-functionalized self-supporting graphene aerogel material; S2, adding the serum sample to be tested to the modified working electrode surface; S3, adding horseradish peroxidase-labeled fibrinogen detection antibody to the modified working electrode surface; S4, adding a matrix-type TMB solution containing H2O2 to the modified working electrode surface; S5, collecting the reduction current of electrochemically active substances on the electrode surface using a chronoamperometry method; S6, calculating the fibrinogen concentration based on the reduction current value and a standard curve. This invention solves the technical problems of low electron transport efficiency and detection sensitivity, structural instability, poor biocompatibility, and difficulty in enriching electroactive substances when using graphene-modified electrodes.

The application belongs to the technical field of fuel cells, and discloses a preparation method of a flexible spherical copper composite ZIF-8 electrode and application thereof. The preparation method comprises the following steps: preparing boron-doped SiNWs, preparing a boron-doped SiNWs electrode, preparing a SiNWs@ZIF-8 electrode, performing heat annealing treatment on the SiNWs@ZIF-8 electrode, and depositing Cu balls by means of chronocoulometry. The application significantly reduces the preparation cost of the electrode, discards the dependence of a traditional ethylene glycol electrocatalytic electrode on noble metals, and does not need to compensate for performance defects by means of noble metal and non-noble metal doping, so that the preparation cost is greatly reduced from the material level.

A method, an electrochemical sensor and a system for selective detection of infections. The method detects a concentration of nicotinamide adenine dinucleotide, NADH, from a bacterial culture through a cyclic voltammetry or chronoamperometry applied to an electrochemically active polymer. Therefore, prokaryotic cells can be detected while eukaryotic cells remain undetected. The infections can include bacterial infections and fungi or yeasts microbial infections.

The invention relates to the technical field of all-solid-state lithium metal batteries, in particular to a solid-state polymer electrolyte and a preparation method and application thereof. According to the invention, trifluoroethanol is used for fluorinating eggshell membrane powder in natural eggshells, and the fluorinated eggshell membrane powder is used as a polyoxyethylene-based solid polymer electrolyte additive. Therefore, the network structure of the polymer can be adjusted, the electrochemical and mechanical properties of the solid electrolyte are enhanced, the growth of lithium dendrites is inhibited, and the cycle capability of a lithium metal battery is enhanced. The lithium ion transfer number of the improved solid-state electrolyte battery is measured by a chronoamperometry, the lithium ion transfer number is higher, lithium fluoride, lithium oxide and the like are more easily generated, and the growth of lithium dendrites is better inhibited. According to the invention, the egg membrane solid electrolyte in the trifluoroethanol fluorinated natural eggshell is added, so that the lithium symmetric battery and the lithium iron phosphate total battery both show excellent performance under various conditions.

The invention relates to the field of electrochemical analysis methods, and particularly discloses a preparation method and application of an electrode capable of simultaneously detecting three pigments of amaranth, carmine and indigo. The preparation method of the electrode comprises the following steps: firstly, preparing Fe / Co Prussian blue seed crystal modified carbon fiber paper through a chemical deposition method; the Fe / Co type Prussian blue crystal seed modified carbon fiber paper is subjected to a hydrothermal reaction, and a hollow cubic octahedron Fe / Co type Prussian blue nanometer material modified carbon fiber paper electrode is prepared; and finally, calcining to obtain the hollow cubic octahedron Fe / Co oxide nano material modified carbon fiber paper electrode (CoFe2O4 (at) CFP). The CoFe2O4-coated CFP electrode serves as a working electrode, differential pulse voltammetry is combined with chronoamperometry, and the content of three pigments including amaranth, carmine and indigo in a sample to be detected can be detected at the same time. Compared with other methods, the method has the advantages that the preparation is simple, the detection is rapid, the method can be used for simultaneously determining amaranth, carmine and indigo in actual samples such as candies, tap water and beverages, the detection sensitivity is high, the range is wide, and the method has great practical application potential.

The invention discloses a boron-doped diamond electrode with high oxygen evolution potential, which is characterized in that monocrystalline silicon is pretreated by using diamond grinding liquid, the obtained monocrystalline silicon after seed crystal is used as a substrate, and the boron-doped diamond electrode is prepared by using a hot filament chemical vapor deposition method; carrying out oxidation treatment on the boron-doped diamond electrode by utilizing an electrochemical workstation and adopting a chronoamperometry: carrying out oxidation treatment for 10-60 minutes in an acidic electrolyte under the treatment voltage of 2.5-8.5 V by taking a platinum sheet electrode as a counter electrode and a saturated calomel electrode as a reference electrode, so as to obtain the boron-doped diamond electrode with high oxygen evolution potential, according to the invention, the oxygen evolution potential of the boron-doped diamond electrode can be increased, so that the ozone electric synthesis efficiency of the boron-doped diamond electrode is effectively improved.

Typical electrochemical sensors measure target-induced changes in current output. Such measures of target binding are inconsistent across individual sensors, and furthermore, signal will drift over time when the sensor is deployed for long periods. These shortcomings can be avoided by the novel use of chronoamperometry to measure current decay kinetics as the indicator of target binding. Current decay lifetimes will vary in a concentration dependent manner, but remain stable across individual sensors and over time, allowing for calibration-free operation. By these methods, aptamer based electrochemical sensors and other sensor types may be deployed in vivo for extended periods of time and will provide accurate measurement of target binding without calibration.

The invention discloses an electrochemical immunosensing module based on laser-induced graphene and application of the electrochemical immunosensing module in instant detection of escherichia coli. The electrochemical immunosensing module comprises a substrate and an immunosensor array arranged on the substrate; the immunosensor array comprises a working electrode, a reference electrode and a counter electrode; the working electrode is obtained by sequentially modifying chitosan, a horse radish peroxidase labeled escherichia coli antibody and bovine serum albumin on a laser printing graphene electrode; and the counter electrode is a laser printing graphene electrode. According to the electrochemical immunosensing module disclosed by the invention, the detection of E.coli O157: H7 in a sample can be realized, and a chronoamperometry is adopted for detection. In addition, the sensing module disclosed by the invention has very high selectivity on some other common bacteria possibly existing in an actual sample.

The invention relates to the field of electrocatalytic hydrogenation, in particular to an electrocatalytic NADH regeneration method. The method comprises the following steps that foamy copper serves as an anode, a platinum wire serves as a cathode, a KOH solution serves as an electrolyte, in-situ oxidation is conducted through a chronopotentiometry, washing is conducted through water and ethyl alcohol, vacuum drying is conducted, calcination is conducted in a tubular furnace, CuO nanowires are obtained, the CuO nanowires serve as the cathode, the platinum wire serves as the anode, in-situ reduction is conducted on the CuO nanowires through a chronoamperometry, and the Cu nanowires are obtained. Adding thioacetamide and acetic acid into the copper sulfate solution, stirring to obtain a reaction solution, adding the Cu nanowire and the reaction solution into a chemical bath deposition container, heating, washing and drying to obtain a CuxS nanowire; in an inert gas atmosphere, carrying out electrocatalysis on NAD < + > to regenerate 1, 4-NADH; in the step S4, the electric potential of the electro-catalysis is minus 1.1 V vs.Ag / AgCl to minus 1.25 V vs.Ag / AgCl. According to the method, the NADH can be generated by hydrogenation at the 1, 4 position in a high-efficiency and high-selectivity manner.

The present invention discloses a PDA@Zn-MOF ternary composite modified electrode modified with glutamate oxidase, its preparation method and application, belonging to the technical field of electrochemical biosensors. The preparation method of the modified electrode includes: mixing an aqueous solution of zinc nitrate and an aqueous solution of 2-methylimidazole, drying to obtain Zn-MOF powder, adding it to a PBS buffer solution containing dopamine hydrochloride, and modifying it onto a conductive electrode by a drop-coating method or a potentiostatic method, and then drop-coating a glutamate oxidase solution. By measuring the current response value of the glutamate solution through the chronoamperometry (i-t method) and comparing it with plant samples, the glutamate concentration in plant molecules can be detected. The biosensor of the present invention can online monitor the change of glutamate concentration in plants, and has the advantages of simple preparation, high sensitivity and fast response speed.

This invention discloses a method for the catalytic reduction of phenylacetylene to styrene using a palladium cluster-modified copper foam electrode. The method involves first immersing cleaned copper foam in an aqueous palladium salt solution and allowing it to react at room temperature for 6–12 hours to prepare the palladium cluster-modified copper foam electrode. Then, a three-electrode system is used, employing a chronoamperometry method to achieve the electrocatalytic partial hydrogenation of phenylacetylene to styrene. The palladium cluster-modified copper foam electrode involved in this invention exhibits high catalytic activity and high selectivity for the partial hydrogenation reaction of phenylacetylene. Furthermore, the electrode preparation method is simple, low-cost, and environmentally friendly, thus this invention possesses extremely high potential commercial value.

The invention provides a method and a device for detecting fibrinogen in a perioperative period. The method comprises the following steps: S1, modifying the surface of a working electrode of a screen-printed electrode with an antibody-functionalized self-supporting graphene aerogel material; s2, dropwise adding a serum sample to be detected to the surface of the modified working electrode; s3, dropwise adding a fibrinogen detection antibody labeled by horse radish peroxidase to the surface of the modified working electrode; s4, dropwise adding a matrix type TMB solution containing H2O2 to the surface of the modified working electrode; s5, collecting the reduction current of the electrochemical active substance on the surface of the collector by a chronoamperometry; and S6, calculating the fibrinogen concentration according to the reduction current value and the standard curve. According to the invention, the technical problems of low electron transmission efficiency and detection sensitivity, unstable structure, poor biocompatibility and difficulty in enrichment of electroactive substances existing in a graphene modified electrode are solved.

The application belongs to the field of nano-biosensors, and discloses an aptamer sensor for chronoamperometry detection, a preparation method and application thereof. Gold nanoparticles are loaded on conductive glass by using in-situ reduction method, and then DNA aptamer is modified. The DNA aptamer can specifically adsorb target bacteria in a test solution on the surface of the material and generate a current response linearly related to the concentration of the bacteria solution. A PBS buffer solution containing MgCl2 is used as an electrolyte, and the chronoamperometry method can be used to measure the current response of different concentrations of Staphylococcus aureus. The new nano-biosensor provides a practical new method for on-site rapid detection of bacteria, and can be widely used in the fields of food detection and environmental detection.