16results about How to "Highly selective detection" patented technology

The invention discloses a preparation method and application of a magnetic enrichment composite SERS (Surface Enhanced Raman Scattering) detection chip, gold nanoparticles are electrostatically adsorbed on the surface of a magnetic ferroferric oxide nanoring, the prepared material is subjected to cyclodextrin modification, nanogaps among the gold nanoparticles form hot spots, a local electromagnetic field enhancement effect is generated, and the magnetic enrichment composite SERS detection chip is obtained. The cyclodextrin molecules adsorb PAHs in the environment through a hydrophobic effect and are fixed in an electromagnetic field enhancement area, amplification of Raman signals is achieved, the magnetic material serves as a carrier, aggregation of gold nanoparticles can be effectively prevented, SERS signals can be further enhanced through a magnetic enrichment effect, and therefore, the method has the advantages that the method is simple, and the application prospect is wide. The high-sensitivity and high-selectivity detection of PAHs in the tail gas of the engineering machinery vehicle is realized by constructing the magnetic composite SERS nano sensing chip.

The invention discloses a giant magnetoresistive sensor-based NO2 gas detection device and a preparation method thereof, and relates to the technical field of magnetic sensors, the giant magnetoresistive sensor-based NO2 gas detection device comprises: a test chamber having a gas inlet and a gas outlet, the upper and lower surfaces of the test chamber being respectively provided with permanent magnets; the giant magnetoresistance chip is arranged in the test chamber, and the direction of a magnetic field formed by the permanent magnet vertically penetrates through the giant magnetoresistance chip; an MOFs film is arranged on the surface of the giant magnetoresistance chip. According to the invention, high-selectivity detection of the NO2 gas can be realized by means of the giant magnetoresistance sensor by utilizing the inherent paramagnetic characteristic of the NO2 gas; the giant magnetoresistive sensor is combined with the gas sensitive material MOFs, so that the sensitivity response to NO2 can be greatly improved; by adopting the MEMS technology, the miniaturization of the whole detection device is realized; each sensor can work independently and can also be connected in series or in parallel to form a sensing array, so that the sensitivity and selectivity of the sensor to NO2 gas are further improved; the whole sensor is simple in structure and easy to integrate, and has a good application prospect and a wide application range.

The invention discloses a method for quantitatively detecting mercury ions based on surface enhanced Raman scattering technology, wherein a gold nano-finger array structure is first obtained by nano-imprinting, and then a specific single-stranded DNA is modified on the Au nano-finger array structure by sulfur-hydrogen bonds, and the finger array structure collapses during the volatilization of the DNA solution, and finally, the single-stranded DNA lying on the Au surface is converted into a double-stranded DNA spiral space structure perpendicular to the Au surface by titrating the mercury ion solution, so that the terminal base molecules in the DNA are away from the coupling enhanced electromagnetic field formed in the gap, and thus the SERS signal thereof is reduced. The invention can simultaneously realize the interference-free high selectivity and high sensitivity detection of Hg ions in a mixed solution.

The invention discloses an NO2 gas sensing material, an NO2 gas sensor and a preparation method and application of the NO2 gas sensing material and the NO2 gas sensor. The NO2 gas sensing material is a semiconductor substrate material doped with variable-valence metal elements; the material of the semiconductor substrate is BiOX, and the element X is at least one of Cl, Br and I; the variable-valence metal element is a variable-valence transition metal element. The invention provides a design and preparation method of a gas sensor capable of rapidly detecting NO2 at room temperature. The method can realize reversible detection of NO2 at room temperature.

The invention discloses an electrochemical biosensor as well as a preparation method and application thereof, belongs to the technical field of detection, and aims to improve the detection sensitivity, specificity and detection accuracy of key biochemical substances of neurodegenerative diseases. The sensor comprises a substrate layer, a liquid inlet, a liquid outlet, a reference electrode and a counter electrode, the substrate layer comprises a PDMS flexible lower cover layer, a P3HT-Cu NWs conductive sensitive layer and a PDMS flexible upper cover layer, a micro-channel layer is arranged on the PDMS flexible upper cover layer, a channel is arranged in the micro-channel layer, and the P3HT-Cu NWs conductive sensitive layer is connected with a flexible flat cable. The preparation method comprises the following steps: preparing Cu NWs, preparing a P3HT-Cu NWs mixed solution, preparing a PDMS flexible lower cover layer, coating the PDMS flexible lower cover layer with the P3HT-Cu NWs mixed solution to obtain a P3HT-Cu NWs conductive sensitive layer, preparing a PDMS flexible upper cover layer, and bonding and sealing the PDMS flexible lower cover layer and the PDMS flexible upper cover layer to obtain the substrate layer.

The present invention relates to a method for detecting horseradish peroxidase by forming a fluorescent copolymer at room temperature and an enzyme-linked immunosorbent assay for detecting cardiac troponin type I, and belongs to the field of nano-biosensor technology. The method comprises: generating a green fluorescent copolymer based on p-phenylenediamine and polyethyleneimine under the action of horseradish peroxidase to detect horseradish peroxidase. In addition, in view of the wide application of the enzyme in immunoassay, we use it as a marker enzyme to construct an immunofluorescence sensing platform for detecting cardiac troponin type I. The fluorescent copolymer nanoparticles based on p-phenylenediamine and polyethyleneimine in the present invention have the advantages of room temperature synthesis, simple steps, strong fluorescence, etc. The constructed immunosensor platform successfully realizes the detection of cardiac troponin type I in the serum samples of patients with acute myocardial infarction. The experimental results are consistent with those of the standard test kit, which shows that the immunofluorescence test kit designed by us has great potential in disease diagnosis.

The invention discloses a near-infrared double-state light-emitting platinum complex fluorescent probe and application thereof in hypochlorite detection. The structural formula of the near-infrared double-state light-emitting platinum complex fluorescent probe is shown in the specification. R1 and R2 are one of H, CH3, C2H5 and C (CH3) 3; the four technical elements of near-infrared emission, double-state luminescence, a platinum complex phosphorescent probe and hypochlorite specific recognition are integrated into the same molecular system for the first time, and a novel platinum complex fluorescent probe which keeps efficient near-infrared luminescence in a solution state and an aggregation state and realizes high-sensitivity and high-selectivity detection on hypochlorite is provided. The double dilemma of solid state quenching of a traditional ACQ material and weak luminescence of a solution of a classical AIE material are broken through, and the blank in the technical field is filled. The novel platinum complex fluorescent probe shows high selectivity, high stability, wide pH application range, low cytotoxicity and good biocompatibility on hypochlorite.

This invention provides a flexible multi-gate single-channel OECT molecularly imprinted sensor and its fabrication method, belonging to the field of flexible chemical sensor technology. This sensor employs a unique multi-gate single-channel integrated structure with gates symmetrically arranged at equal intervals around the source and drain electrodes and synergistically controlled within the same channel. Combined with MIP and OECT technologies, it possesses both high-sensitivity amplification capability and highly specific recognition of three non-electroactive BCAAs (leucine, isoleucine, and valine), enabling the detection of multiple substances with a single device.

The invention discloses a preparation method and application of a ratiometric fluorescent paper-based sensor. The preparation method comprises the following steps: (1) preparing a UiO-66-NH2-rhodamine B composite material; and (2) dropwise adding a suspension containing the UiO-66-NH2-rhodamine B composite material into the hydrophilic sensing area of the paper-based substrate, and carrying out a reaction I to obtain the ratiometric fluorescent paper-based sensor, the surface of the paper-based substrate is modified by using carboxymethyl cellulose to introduce a large number of carboxyl groups; the paper-based substrate comprises a hydrophilic sensing area and a hydrophobic area. Due to the built-in self-calibration characteristic of the ratiometric fluorescence sensor disclosed by the invention, the interference of factors irrelevant to analysis can be inhibited, and higher sensitivity and more obvious visual detection effect are shown in qualitative and quantitative analysis processes.

The invention discloses an immune ratio electrochemical sensing platform based on steric hindrance response and a preparation method, and relates to the technical field of biosensors, and the preparation method mainly comprises the following steps: taking cerium dioxide and a ferrous sulfate heptahydrate solution to react to prepare a ferroferric oxide nano material; the preparation method comprises the following steps: dispersing a ferroferric oxide nano material into a molybdenum disulfide solution to prepare magnetic nano particles, heating a chloroauric acid aqueous solution and a trisodium citrate solution to react until the solution becomes red to obtain a gold nano particle solution, and uniformly dispersing the magnetic nano particles into a phosphate buffer solution to obtain a gold nano particle solution; the preparation method comprises the following steps: preparing a magnetic nano-particle layer, depositing the magnetic nano-particle layer on the surface of a pencil lead electrode to obtain a magnetic nano-particle layer, coating the obtained pencil lead electrode with a gold nano-particle layer, and coating the gold nano-particle layer of the pencil lead electrode with a C reactive protein antibody by using an EDC / NHS cross-linking agent; according to the sensor disclosed by the invention, the C-reactive protein antibody is fixed on the sensor, so that high-accuracy, sensitive and high-selectivity detection on the CRP is effectively realized.

The application relates to an Au / SnO2 / GND composite gas-sensitive material-based MEMS nitrogen dioxide sensor and a preparation method thereof, and belongs to the technical field of gas sensors. The sensor is composed of a metal tube seat and a MEMS micro-hot plate chip which are coaxially arranged and fixedly packaged, and the Au / SnO2 / GND composite gas-sensitive material is coated on the surface of the chip interdigital electrode. 3 The sp 2 Volume evolution during phase inversion is synchronous with the SnO2 crystallization process, the SnO2 shell and the carbon skeleton are tightly bonded at the atomic scale, lattice strain is induced at the heterojunction interface, and a high concentration of oxygen vacancies is generated; meanwhile, the ultraviolet photochemical reduction method is used to realize the fine and uniform dispersion of gold nanoparticles at a very low noble metal loading (0.5wt%-1.5wt%), and the high concentration of oxygen vacancies generated by the lattice strain constructs a double enhancement mechanism, which significantly improves the catalytic activity of the material and the sensitivity of the sensor.

The invention provides a novel electrochemical sensor for detecting CREG1 based on a surface molecular imprinting technology and a preparation method of the novel electrochemical sensor. Comprising the following steps: step 1, preparing a reagent solution required in a manufacturing process; step 2, polishing the glassy carbon electrode (GCE); 3, AuNPs / GCE is prepared; step 4, preparing CREG1 / GA (at) CS / AuNPs / GCE; step 5, preparing MIP / GA (at) CS / AuNPs / GCE; and step 6, scanning in the redox probe solution by adopting a differential pulse voltammetry (DPV), and determining the content of the CREG1. According to the invention, CREG1 protein is selected as a detection template, and a molecularly imprinted polymer is combined with gold nanoparticles through a surface polymerization method to prepare a corresponding western blot material. Gold nanoparticles are used as a matrix, CREG1 is used as a template, GA (at) CS is used as a protein fixing agent, and polyphenol is used as an imprinted polymer to prepare a surface imprinted material, and the surface imprinted material is measured by measuring the change of sensor current before and after the combination of a molecularly imprinted membrane (MIP) and CREG1. According to the present invention, the surface molecular imprinting technology and the electrochemical sensing technology are combined to construct the high-sensitivity and high-specificity CREG1 sensor, and the high-sensitivity and high-specificity CREG1 sensor is the novel surface molecular imprinting electrochemical sensor with good biocompatibility, can simply, conveniently and rapidly recognize the CREG1 protein at a low cost, and has characteristics of high sensitivity and high sensitivity. In addition, the method can also be used as a universal sensing platform to be suitable for other proteins.

The invention discloses a tungsten-based oxide composite material and a preparation method thereof, a trihydroxy dibutanone gas sensor and application, the tungsten-based oxide composite material is tungstate-tungsten oxide, and tungstate and tungsten oxide form a heterostructure; the tungsten oxide is W18O49; the tungstate is MWO4, and M is selected from at least one of Fe, Co, Ni, Cu and Sn. The successful design of the material and the preparation of the sensor provide a new thought for the detection of 3H-2B, and the epitaxial growth method can also be popularized to the fields of catalysis, energy and the like, and has extremely high reference value.

The application discloses a high-selectivity acetone gas sensor and a preparation method thereof, and comprises the following steps: providing a MEMS micro-hotplate substrate with a defined active window as a working substrate, in-situ growing an epsilon-WO3 nanostructure array in the active window, sequentially constructing a super-thin NiO continuous shell layer and a discrete CuO catalytic island on the surface of the epsilon-WO3 nanostructure array to form a radial p-n-p heterojunction sensitive structure with epsilon-WO3 as the core and NiO / CuO as the shell, performing a thermal stabilization treatment on the heterojunction sensitive structure, constructing a ZIF-8 molecular sieve film or a ring-shaped fluorinated ionomer selective layer on the surface of the heterojunction sensitive structure to obtain a high-selectivity sensor device, effectively blocking the passage of interfering molecules, and significantly improving the selectivity ratio and the anti-cross interference capability of the sensor device; meanwhile, based on the MEMS micro-hotplate substrate and the thermal stabilization treatment process, the device has good structural stability, low power consumption characteristics and compatibility with a standard semiconductor process, and high selectivity for acetone is realized while high sensitivity is ensured.

The invention discloses a hydrazine hydrate detection fluorescent probe NPB with 1, 8-naphthalimide as a parent and a preparation method and application thereof. The fluorescent probe takes 1, 8-naphthalimide as a fluorophore, and the structure of the fluorescent probe is shown in the specification. The fluorescent probe NPB based on 1, 8-naphthalimide as a matrix is constructed through a condensation reaction, and the probe shows excellent selectivity and high-sensitivity detection performance on hydrazine hydrate in a solution. In addition, the probe NPB is stable in structure, can be made into a test paper form, and is suitable for rapid detection of trace hydrazine hydrate in water samples, food and air; meanwhile, due to low cytotoxicity, the probe can be successfully applied to hydrazine hydrate detection in a PK-15 active cell system. The preparation method of the fluorescent probe is simple and convenient, raw materials are easy to obtain, and the product is solid powder, is convenient to store and has good application and development prospects.

The invention provides an Au TOHs (at) ZIF-67 / PA-6 composite material for high-selectivity detection of mixed pesticides and a preparation method thereof.The Au TOHs (at) ZIF-67 / PA-6 composite material is successfully obtained by synthesizing a gold trioctahedron (Au TOHs) with a high index surface, loading the gold trioctahedron (Au TOHs) with the high index surface on ZIF-67 to obtain Au TOHs (at) ZIF-67, and soaking the Au TOHs (at) ZIF-67 / PA-6 composite material on a nylon six filter membrane. The Au TOHs (at) ZIF-67 / PA-6 composite material is used as an SERS (Surface Enhanced Raman Scattering) substrate, so that the multifunctionality of substrate adsorption is enhanced, the universality is high, the application range is wide, the selectivity is high, the separation and enrichment efficiency is improved, the SERS detection sensitivity is greatly improved, and high-selectivity detection of mixed pesticides is realized.