144results about How to "Wide detection linear range" patented technology

The invention provides a simulative-target metabonomics analytic method based on combination of liquid chromatography and mass spectrum. The method includes following steps: respectively manufacturing to-be-analyzed samples into merged samples according to groups; automatically collecting secondary mass spectrums of metabolites in each merged samples through data of UHPLS / Q-TOF MS with dependence on a collecting mode; extracting a retaining time and information of parent ions and daughter ions of the metabolites by qualitative analytic software; screening out characteristic ion pair information of the metabolites according to daughter ion response intensity; summing the characteristic ion pair information of each merged samples; and scanning the obtained characteristic ion pair of the metabolites by UHPLC / QQQ MS through a dynamic multi-reaction monitoring mode in an actual sample for obtaining a corresponding spectrogram; and performing integration through quantitative analytic software to obtain the metabolites in the to-be-analyzed samples and content information thereof.

The invention aims at providing an electrochemical sensor for sensitively detecting heavy metal cadmium ions and a preparation method of the electrochemical sensor. The structure of the sensor is formed by an electrochemical workstation, an electrolytic cell and electrodes; the electrodes include a platinum wire counter electrode, a silver / silver chloride reference electrode and a working electrode, wherein the working electrode refers to a glassy carbon electrode adopting nitrogen-sulfur codoping and graphite porous carbon / Nafion / bismuth film modification. The electrochemical sensor can realize sensitive detection of trace heavy metal cadmium ions, the detection linear range is 4-80 micrograms / L, and the detection limit reaches 0.1 microgram / L. By combining with good properties of a bismuth film, a Nafion film and a nitrogen-sulfur codoped porous carbon material, the electrochemical sensor has the performances of high sensitivity, good selectivity, wide linear range, good reproducibility, good stability and the like and can be applied to detecting the heavy metal cadmium ions in an actual water sample.

The invention relates to a dinucleotide-labelled ratio electrochemical immunosensor. The dinucleotide-labelled ratio electrochemical immunosensor is characterized in that DNA3 of sulfydryl and ferrocene are respectively labelled at the two assembled ends of the surface of a gold electrode and are hybridized with methylene-blue-labelled complementary DNA1-antibody1 so as to form a ratio electrochemical immunosensor interface. When target protein exists, a DNA2-antibody2, the target protein and the DNA1-antibody1 form sandwiched immune complex to generate a vicinal effect, and DNA2 is hybridized with DNA1, so that the DNA1-antibody1 is separated from a sensing interface, and freed DNA3 forms a hairpin structure on the surface. In the process, methylene blue and the ferrocene with electrochemical activity are separated from and close to the surface of the electrode respectively, and the oxidized electric currents of the methylene blue and the ferrocene are reduced and increased respectively. By detecting the ratio of the two currents, the concentration of the target protein in the solution is detected. The immunosensor is high in sensitivity, wide in the detection range, realizes fast and one-step detection of protein, and has clinical application value.

The invention relates to the preparation and application of nano-materials, in particular to a Prussian blue nano-particle preparation method through reverse micelle. The invention aims to overcome the disadvantages of poor stability of Prussian blue and easy reunion of nano-particles. The Prussian blue nano-particles prepared through reverse micelle are small in particle size and are dispersed evenly. The nano-particles are decorated on an electrode to detect H2O2 so as to realize the electrochemical analysis and application of the nano-particles; and the nano-particles are characterized by high sensitivity, good stability, low detection limit and wide H2O2 analysis and detection linear range. Enzyme can be fixed on the surface of the electrode modified by the nano-particles to prepare an enzyme biosensor so as to realize detection and analysis of the corresponding enzyme substrates and reduce the cost of enzyme biosensors.

The invention provides preparation and application of an immunochromatography method and test paper for quantitative detection of prealbumin. The test paper consists of a bottom plate, a sample pad, a conjugate pad, a nitrocellulose membrane and a piece of water absorbing paper, wherein the sample pad, the conjugate pad, the nitrocellulose membrane and the water absorbing paper are sequentially adhered to the bottom plate in a lap joint manner and are respectively and partially overlapped; a detection line and a quality control line are arranged on the nitrocellulose membrane; the quality control line is wrapped with a donkey-anti-rat antibody. A method comprises the following steps: (1) adding a solution which is of known concentration and comprises a prealbumin standard substance onto the sample pad of the test paper, and drawing a standard curve; (2) adding a solution of a substance to be tested, performing reaction, and reading content according to standard curves. The test paper and the detection method provided by the invention are high in sensitivity, that is, up to pg / mL, wide in detection linearity, convenient to operate, and short in time, that is, results can be obtained within only 10-20 minutes.

The invention aims at providing an electrochemical sensor for sensitively and selectively detecting dopamine (DA) and uric acid (UA) simultaneously and a preparation method. The sensor structurally comprises an electrochemical working station, an electrolytic cell and electrodes, wherein the electrodes include a platinum-wire counter electrode, a silver / silver chloride reference electrode and a working electrode; the working electrode means a glass-carbon electrode modified by microwave-peeled porous carbon. The electrochemical sensor provided by the invention has excellent properties such ashigh sensitivity, good selectivity, wide linear range and low detection limit in detecting the DA and the UA since the microwave-peeled porous carbon for modifying the electrode has excellent properties such as large specific surface area, porous structure, excellent electrocatalytic activity property and good conductivity. The electrochemical sensor can be used for qualitatively and quantitatively detecting the contents of the DA and the UA in actual biological samples.

The invention discloses an ECL (electrochemiluminescence) determining method for ATP (adenosine triphosphate). According to the ECL determining method for ATP, gold nanoclusters with high quantum yield are taken as an ECL probe, a manganese dioxide nanomaterial is taken as a quenching agent, when ATP exists, an aptamer can be specifically bound with ATP and DNAzyme cannot be formed, glutathione and manganese dioxide on an electrode surface are subjected to a redox reaction, ECL signals of the gold nanocluster probe are restored gradually with increase of ATP concentration, and content of ATP is determined. Logarithm of ATP concentration in the concentration range of 3.6*10<-12>-3.6*10<-3> mol / L has a linear relation with the change value of ECL intensity, and limit of detection is 1.4*10<-12> mol / L. The method is simple to operate, low in cost, high in sensitivity and good in reproducibility and can be used for determining ATP in an actual sample, thereby having better clinical application prospect.

The invention discloses a preparation method of a nitrogen and chlorine double-doped fluorescent carbon quantum dot. The preparation method comprises the steps of with amino sugar hydrochloride or amino acid hydrochloride as raw materials, simultaneously supplying a carbon source, a nitrogen source and a chlorine source, dissolving the raw material into ultrapure water, stirring so as to obtain asettled solution, carrying out hydrothermal reaction, cooling a synthesized product, filtering, and carrying out centrifugation and dialysis, so as to obtain the water-soluble nitrogen and chlorine double-doped fluorescent carbon quantum dot. By utilizing a one-step reaction, the required raw material is few, byproducts are few, and the method has the characteristics of high efficiency, economy and the like. The carbon quantum dot prepared by virtue of the carbon quantum dot has stable fluorescent property and low toxin, can be applied to the detection of Fe<3+> and simultaneously has wide application prospect in the aspects of fluorescent ink, sewage treatment and the like.

The invention discloses a preparation method of a Co4S3 / nitrogen doped graphene composite material and application thereof, and belongs to the field of inorganic material synthesis and analysis. The composite material is prepared as follows: firstly using ammonia water to regulating alkaline environment, then using hydrazine hydrate and graphene oxide for reaction and conversion into nitrogen doped graphene, and then adding cobalt acetate and thiourea to prepare the Co4S3 / nitrogen doped graphene composite material by a solvent thermal process. The method has simple process and low cost, the main reaction is performed in an aqueous phase, reaction conditions are mild, an electrochemical sensor constructed by use of the Co4S3 / nitrogen doped graphene composite material can show a strong catalytic effect on electrochemical reduction of hydrogen peroxide because of synergistic effect of the nitrogen doped graphene with a high surface area, high conductivity and good biocompatibility and a Co4S3 nano material with good electronic transfer characteristics, and the electrochemical sensor has the advantages of wide detection linear range, low detection limit and high sensitivity and selectivity, and is successfully used to detect the hydrogen peroxide in real samples.

The invention discloses a zinc ion fluorescent probe, a preparation method and a method for detecting zinc ion content. The chemical formula of the fluorescent probe is as shown in the specification, wherein R1 is -Cl, -Br, -I, -NO2 or NH2; R2 is -Cl, -Br, -I, -NO2 or NH2. The preparation method is characterized in that ammonium acetate and TBAB are used as the catalysts, 1, 3-amino alcohol, a aniline derivative and a benzaldehyde derivative are used as the raw materials, and a series of Zn<2+> fluorescent probes in a water phase under microwave conditions. The zinc ion fluorescent probe is good in structural stability. The preparation method is simple and easy to operate, high in product yield and free of pollutant generation. The detection method has the advantages that the detection method is simple, the Zn<2+> content can be detected in a quantified manner only by detecting fluorescence intensity, and the method is good in detection accuracy; a used solvent is an ethanol solution which is nontoxic and environmentally friendly; the method is wide in detection linear range, detection limit of the method is 1*10<-6>mol / L, and the method is applicable to the detection of the trace Zn<2+> content of environments and food and the in-vivo and in-vitro trace Zn<2+> content.

The invention relates to an air coupling ultrasound-based ballastless track plate detection device. The output end of a signal transmitting and receiving element is connected with the input end of a data processing unit through an A / D conversion circuit and a built-in amplifier; the data processing unit is connected with a storage unit; the signal transmitting and receiving element emits transmitting signal to a signal transmitting probe group; the signal transmitting and receiving element receives the echo signals of a signal receiving probe group through an external amplifier; and the signal transmitting probe group and the signal receiving probe group are horizontally arranged above a steel track. With the method disclosed by the invention adopted, the comprehensive scanning of the interlayer delamination and water seepage of a track plate and a mortar layer, the block missing of the track plate, and the internal deep crack of the track plate can be performed. The air coupling ultrasound-based ballastless track plate detection device has the advantages of many defect scanning types, wide detection linear range and high detection efficiency. With the air coupling ultrasound-based ballastless track plate detection device adopted, the visual display of a detection result is realized; and a bonding condition between the track plate and the mortar layer is judged according to the phase change condition of echo signals.