22 results about "Square wave voltammetry" patented technology

The invention provides a method for detecting chloramphenicol residues in animal food by adopting a molecular imprinting sensor, which comprises the following steps: preparing the molecular imprinting sensor with specific recognition on CAP, and providing an electrochemical detection system of the molecular imprinting sensor for detecting the chloramphenicol residues in the animal food, fitting to obtain a calculation formula of chloramphenicol concentration detected by the molecularly imprinted sensor; treating an animal food sample, and mixing the animal food sample with a standard concentration CAP solution according to a volume ratio of 1: 9 to obtain a to-be-detected sample solution; scanning the to-be-detected sample liquid through the molecular imprinting sensor by adopting a square wave voltammetry method to obtain a peak current value; and obtaining the concentration of chloramphenicol in the sample solution to be detected according to the peak current value and a calculation formula of chloramphenicol concentration detected by the molecular imprinting sensor. The method is sensitive, accurate and practical.

This invention discloses a G4-DNA tetrahedral probe electrode, its preparation method, applications, and application methods. This invention utilizes four DNA strands to self-assemble into a DNA tetrahedral structure based on Watson-Crick hybridization. The DNA tetrahedron and G4 strand can be connected to the electrode based on the interaction between thiol groups and the gold electrode, and complementary base pairing. The addition of the DNA tetrahedron, through the construction of a reasonable probe density, further improves the detection sensitivity. This invention utilizes square wave voltammetry for electrochemical detection of malachite green. The content of malachite green can be determined based on the strength of the current signal of its characteristic peak. Rapid detection of malachite green can be achieved in a short time, with a minimum detection concentration of 3.65 μg / kg, showing potential for on-site detection. Six repeated tests using this electrode yielded almost identical detection signals, indicating that the electrode has good reusability and stability.

An electrochemical method for detecting, identifying, and quantifying ions and nutrients dissolved in water through voltammetry, and equipment to carry out the method, including: a preparation / placement stage of a sensor, with a reference electrode, working electrode, and counter electrode, in a potentiostat; a stage for contacting a sample or analysis solution containing the analyte with the sensor; a stage for applying, controlled via software from a computer system, electrical stimulation to the sample through Cyclic Voltammetry, Normal Pulse Voltammetry, Differential Pulse Voltammetry, or Square Wave Voltammetry, with a step potential and pulse amplitude range between −3,000 mV and 3,000 mV; and a stage for characterizing one or more analytes based on at least one measurement of the signals resulting from the oxidation-reduction of the analyte(s).

Provided is an electrode arrangement configured for detecting humic and fulvic acids in a soil matrix by means of squarewave voltammetry. The electrode arrangement comprises a working electrode with a coating comprising an admixture of ionic liquid 1-butyl-3- methylimidazolium tetrafluoroborate (BMIM-BF4) and sulfonated tetrafluoroethylene-based fluoropolymer-copolymer - sulfur trioxide (SO3) at a molar ratio of 1:1, sulfonated tetrafluoroethylene-based fluoropolymer-copolymer to carbon particles at a mass ratio in a range of between 1:10 and 1:15, sulfonated tetrafluoroethylene-based fluoropolymer-copolymer to polymeric adsorbent non-ionic aliphatic acrylic resin at a mass ratio in a range of between of 1:50 and 1:60, and a cross-linked hydrogel.

The invention relates to a method for electrochemically detecting chloramphenicol by using molecular imprinting. The method is characterized in that a chloramphenicol molecularly imprinted polymer prepared from a temperature-sensitive monomer N-isopropylacrylamide and Dawson type tungsten phosphate (P2W18) are jointly modified on a substrate electrode through a simple and controllable electrostatic layer-by-layer self-assembly method. The modified electrode synthesized by the method disclosed by the invention is used as a working electrode, a saturated calomel electrode is used as a reference electrode, a platinum electrode is used as an auxiliary electrode, and the electrochemical sensing performance of the modified electrode on chloramphenicol is respectively evaluated by cyclic voltammetry, differential pulse voltammetry and square wave voltammetry. According to the modified electrode, the sensitivity of an electrochemical signal is synergistically enhanced through the high-selectivity imprinting cavity of the molecularly imprinted polymer and the rapid and reversible oxidation-reduction activity of P2W18, the detection linear range of chloramphenicol is 0.1 nM to 10 [mu] M, and the detection limit of differential pulse voltammetry is as low as 0.145 nM; and a good application prospect is provided for preparing a uniform and controllable molecularly imprinted polymer composite modified electrode material in the future. At present, an indissolvable molecularly imprinted polymer material is integrated into an electrochemical sensor through an electrostatic layer-by-layer self-assembly technology, so that the research on improving the selectivity of chloramphenicol detection and reducing the detection limit is rarely reported.

The invention discloses a lead ion ultra-trace detection method based on a non-mercury film modified microarray electrode technology, which comprises the following steps: providing a microarray working electrode composed of a plurality of glassy carbon microelectrode units, and carrying out mechanical polishing and / or electrochemical activation on the exposed surface of the microarray working electrode; the microarray working electrode, a reference electrode and a counter electrode are jointly placed in a modification solution containing a non-mercury electroactive substance, a continuous non-mercury electroactive film layer is formed on the exposed surface of each glassy carbon microelectrode unit through electrochemical deposition, and the non-mercury electroactive film layer is in direct electric contact with a glassy carbon substrate; placing the microarray working electrode modified by the non-mercury electroactive film layer, a reference electrode and a counter electrode in a buffer electrolyte, and carrying out electrochemical cleaning; a to-be-detected sample and a buffer solution are mixed to form a to-be-detected solution, the to-be-detected solution is put into a three-electrode system, anodic stripping scanning is conducted through differential pulse voltammetry or square wave voltammetry, and the lead ion concentration in the sample is determined. The method does not need complex pretreatment, the detection limit reaches 0.1 mu M (20 mu g / L), and lead ions in complex matrixes such as clinical serum and the like can be rapidly and accurately detected.

The invention discloses a circulating miR-375 high-sensitivity electrochemical detection device and a circulating miR-375 high-sensitivity electrochemical detection method based on a three-foot DNA walker. According to the device, a large number of probes B are generated through a strand displacement amplification technology, and chain extension and specific splitting decomposition of Nb. BbvCI in the presence of target miR-375 are initiated by utilizing Klenow polymerase. After the probe B is hybridized with the Block chain, the inactive three-chain DNA walker is activated. The activated walker moves on a gold electrode interface supported by the TDN, and the Fc labeled probe is cracked to generate an electrochemical signal. And a square wave voltammetry method is adopted to detect signals, so that high-sensitivity detection of the circulating miR-375 is realized. The method has high selectivity, only miR-375 can cause obvious signal change, and other interference sequences and mismatched sequences are not obviously influenced. The method shows good performance in clinical samples, can distinguish glioma patients in different stages, and has important clinical application value.

This invention belongs to the field of electrochemical sensor technology and aims to solve the problems of low sensitivity, insufficient charge transport efficiency, and weak target enrichment ability of existing electrochemical detection methods for niclosamide. It provides a highly sensitive electrochemical detection method and sensor for niclosamide based on MOF / COF composite materials. The sensor uses a glassy carbon electrode modified with MOF / COF composite material as the working electrode, combined with an auxiliary electrode and a reference electrode to form a three-electrode system. It utilizes the synergistic effect of the high specific surface area and high catalytic activity of MOF and the good conductivity and ordered porous structure of COF to enhance the adsorption, enrichment, and electron transfer efficiency of niclosamide. The detection method achieves accurate detection of niclosamide by optimizing electrochemical test parameters and employing square wave voltammetry. This invention features a low detection limit, wide linear range, strong anti-interference ability, excellent stability and reproducibility, and can rapidly detect niclosamide in water, soil, fish, and tablets, possessing broad practical application value.

The invention relates to a CRISPR-Cas13a (clustered regularly interspaced short palindromic repeats-CRISPR-Cas13a) system-based nucleic acid detection method for electrochemical detection of influenza B virus, a kit and application. The kit comprises: an (RT) RAA primer group, which is used for targeting an influenza B virus HA gene conserved region; the CRISPR-Cas13a system contains an LwCas13a protein and crRNA (Complementary Ribonucleic Acid), and the LwCas13a protein and the crRNA can form a complex. The detection method comprises the following steps: performing (RT) RAA isothermal amplification on target RNA; transcribing the T7 to generate single-stranded RNA; the CRISPR-Cas13a is used for identifying the target RNA, activating the trans-cleavage activity and cutting off the electrochemical report RNA; biotin is separated through streptavidin magnetic beads, and methylene blue (MB) redox peak signals are detected through square wave voltammetry. The method has the advantages of high specificity, high sensitivity (100 copy / microliter), high signal response speed, simplicity in operation and the like, and is suitable for field detection. The method has important application value in influenza B virus screening and public health emergency.

The invention discloses a method for detecting dichlorvos in ham in the technical field of meat product pesticide residue detection. The method comprises the following steps: extracting a ham sample by using an organic solvent, and selectively enriching dichlorvos in an extracting solution by using a porous zinc oxide-molybdenum disulfide-graphene quantum dot heterojunction nano composite material; then directly dispersing and modifying the composite material loaded with the dichlorvos on the surface of a glassy carbon electrode to form a sensitive interface, finally detecting by adopting a square wave voltammetry, and quantifying by adopting an external standard method. According to the method, the selective enrichment function of a nano material and the construction of an electrochemical sensing interface are combined into a whole, the complex elution and transfer steps in traditional detection are simplified, the utilization rate and the detection sensitivity of a target object are effectively improved, and the method has good anti-interference capability on complex matrix interference of hams and is suitable for being used in detection of hams. The rapid and high-sensitivity detection of the dichlorvos residue is realized.

The invention discloses a method for detecting thrombin activity in a biological product by using a functionalized electrode, and belongs to the technical field of electrochemical detection. Firstly, thrombin specific substrate polypeptide is fixed on the surface of a silk-screen printing gold electrode through an Au-S bond, and the N end of the polypeptide is modified with ferrocene (Fc) to serve as an electroactive signal molecule; then the surface of the electrode is coated with a cellulose acetate membrane (CA) to obtain a functionalized electrode, and the CA membrane can reduce non-specific adsorption and prevent electrode pollution and signal attenuation; dropwise adding a solution containing thrombin onto the functionalized electrode for reaction; and washing the reacted electrode, testing by using a square wave voltammetry, and obtaining the thrombin activity according to the change of the peak current. The method is convenient to operate, high in specificity, short in consumed time and long in storage time of the functionalized electrode, and is an effective means for detecting the thrombin activity in the biological product.

The application relates to a preparation method and application of a ZIF-8 / Thi / Au-based ratio type electrochemical aptamer sensor, and ZIF-8 / Thi / Au with a signal label function is combined with a catalytic hairpin assembly strategy for the first time to detect mycotoxins, signal amplification is effectively realized, and the detection sensitivity is improved. ZIF-8 / Thi / Au composite materials are synthesized first, and a signal label is prepared by combining a hairpin chain 2. When aflatoxin B1 exists, aflatoxin B1 is combined with an aptamer chain, a complementary chain that is dropped off opens a hairpin chain 1, catalytic hairpin assembly is carried out after a signal label is added, the signal label is combined on the electrode surface, the electrode surface has a high resistance value, and a buffer solution containing [Fe(CN)6] 3‑ / 4‑ is used to carry out electrochemical measurement by using a square wave voltammetry method, a higher ZIF-8 / Thi / Au signal and a lower [Fe(CN)6] 3‑ / 4 signal can be obtained. When no aflatoxin B1 exists, the changes of the two electrochemical signals are opposite. Finally, an electrochemical aptamer sensor for detecting aflatoxin B1 is obtained by the change of the ZIF-8 / Thi / Au and [Fe(CN)6] 3‑ / 4 signal ratio.

The invention provides a multiple miRNA detection electrochemical biosensor, a preparation method, a product and application, and belongs to the technical field of electrochemical detection. The multiple miRNA detection electrochemical biosensor is developed on the basis of an amino-functionalized nano material or a modified avidin nano material, and a specific capture probe and a signal probe marked with different metal ions or biotin are designed; by combining electrochemical detection methods such as two-step sandwich type hybridization reaction and differential pulse voltammetry or square wave voltammetry, quantitative simultaneous detection of multiple miRNAs is realized, the detection process is simplified, the detection efficiency is improved, and the problem that multiple markers cannot be simultaneously detected by a traditional method is solved. In addition, by optimizing hybridization reaction conditions and probe design, the specificity of the sensor is improved, cross reaction is reduced, meanwhile, the stability and reproducibility of detection results are guaranteed, and finally an efficient and accurate tool is provided for clinical detection of miRNA.

The present invention relates to a method for manufacturing an electrochemical sensor based on activated carbon obtained from polyethylene terephthalate (PET) waste, which is prepared as a carbon paste for use in detecting and quantifying heavy metals in aqueous solutions using the square wave voltammetry method. The method comprises using different concentrations of activating agents and activation temperatures, with double heat treatment in oxygen prior to carbonisation.

A method of measuring sensor response for a sample is disclosed. The sample is exposed to an electrochemical aptamer-based (EAB) sensor, where the sensor includes an electrode and one or more aptamers having redox tags. Next, an interrogation is performed by applying an abrupt voltage pulse to the electrode. Two or more data samples are collected at different time values, where each data sample is a redox tag current value. Then at least one measure of the sample is identified using the data samples.

A method of measuring sensor response for a sample is disclosed. The sample is exposed to an electrochemical aptamer-based (EAB) sensor, where the sensor includes an electrode and one or more aptamers having redox tags. Next, an interrogation is performed by applying an abrupt voltage pulse to the electrode. Two or more data samples are collected at different time values, where each data sample is a redox tag current value. Then at least one measure of the sample is identified using the data samples.

The invention provides a microelectrode modification method which can be applied to the technical field of neurotransmitter electrochemical detection and neural microelectrode modification. The method comprises the following steps: electroplating a platinum black nanoparticle film on the surface of a detection site; and electroplating a layer of organic composite film containing a conductive polymer and a carbon nanomaterial on the platinum black nanoparticle film to obtain the surface-modified microelectrode. The invention also provides a method for electrochemical detection of serotonin in the brain. According to the present invention, the specific modification parameters are adopted to achieve the double-layer structure modification structure of the electrode electrochemical site so as to enhance the electrochemical detection performance, and the square wave voltammetry detection method is adopted to improve the serotonin detection precision and the serotonin detection sensitivity, such that the method can be used for the real-time detection and the long-term monitoring of the internal body neurotransmitter of the experimental animal brain.

A method is provided for interrogating an aptamer-based electrochemical sensor using square wave voltammetry. A redox reporter is attached to each aptamer. The current resulting from the interrogation is measured and used to determine the initial distribution of the redox reporter on the surface of the aptamer-coated working electrode of the sensor. The measured current is used to determine the location or distribution of the redox-active species relative to the surface, which is then used to determine the amount of analyte around the electrode.

Methods for interrogating aptamer-based electrochemical sensors using square wave voltammetry. A redox reporter is attached to each of the aptamers. Currents resulting from the interrogation are measured and used to determine an initial distribution of redox reporter above the surface of the aptamer-coated working electrode of the sensor. The measured currents are used to determine a location or a distribution of the redox-active species in relation to the surface, and in turn the amount of analyte about the electrode.

The invention discloses an electrochemical sensor and application thereof in detection of nitrite content in a sample. The electrochemical sensor comprises a probe and a composite electrode; the composite electrode comprises an electrode substrate and a nano composite material modified on the surface of the electrode substrate, the nano composite material is a gold nanoparticle-polyphenylboronic acid-polyarginine nano composite film, and the probe is an iodine elementary substance / iodide probe. According to the method, under the assistance of an iodine elementary substance / iodide probe, the detection of nitrite in a sample is realized by utilizing a square wave voltammetry method and AuNPs-poly (PBA)-poly (Arg) / GCE. The electrochemical sensor has the advantages of being simple, rapid, sensitive, low in detection limit, good in reproducibility and the like, and has potential application prospects in the aspects of food safety and environmental protection.

The invention relates to the technical field of hydrogen peroxide sensors, in particular to a hydrogen peroxide sensor and a preparation method and application thereof. B, soaking the pretreated electrode in aniline-acid electrolyte, and obtaining a polyaniline modified electrode by using an electrochemical polymerization method; c, the polyaniline modified electrode is soaked in a platinum precursor solution, and a grape platinum nanoparticle-polyaniline composite electrode is obtained through an electrochemical method; and D, carrying out shape modification on the vibrio platinum nanoparticles in the vibrio platinum nanoparticle-polyaniline composite electrode by adopting a polarized square wave voltammetry to form a cubic platinum nanoparticle-polyaniline composite electrode, thereby obtaining the hydrogen peroxide sensor. According to the preparation method of the hydrogen peroxide sensor, the preparation method is simple and high in operability, and the obtained hydrogen peroxide sensor shows high detection sensitivity, high anti-interference performance and high performance stability on hydrogen peroxide.

The invention relates to a preparation method and application of an electrochemical aptamer sensor, in particular to an electrochemical aptamer sensor for detecting dibutyl phthalate as well as a preparation method and application of the electrochemical aptamer sensor. According to the invention, the electrochemical aptamer sensor with high sensitivity and high selectivity is constructed through compounding of Fe3O4 magnetic nanoparticles and a Hemin-coated HKUST-1 metal organic framework, and is used for detecting dibutyl phthalate (DBP); by adopting the Hemin-coated HKUST-1 as a signal amplification unit, the electron transfer rate of an electrode interface is effectively enhanced, so that the current response in square wave voltammetry measurement is obviously enhanced, and the signal stability and repeatability are ensured. The sensor disclosed by the invention has relatively high selectivity on PAEs substances with similar structures and common food interferents, and a DBP signal is obviously higher than that of other interferents, so that reliable detection in a complex matrix is ensured, and a novel, reliable and efficient analysis platform is provided for food safety and environmental monitoring.