38results about How to "Efficient and sensitive detection" patented technology

The invention discloses a method for quickly detecting copper ions in a solution. The method comprises the following steps of: reacting a reducible water-soluble compound with a water-soluble compound which contains precious metal in a polyhydroxy water-soluble compound which is used as a protective agent to obtain a detecting solution containing precious metal nano particles, which are modified by the polyhydroxy water-soluble compound; supplying two parts of the same detecting solutions with equal quantities, adding the solution without the copper ions and a solution to be detected, which are isometric, into the two parts of the detecting solutions respectively, and forming a first mixing solution and a second mixing solution which are corresponding; and judging whether the copper ions exist in the solution to be detected or not according to the color variation of the second mixing solution relative to the color of the first mixing solution or according to the variation of the ultraviolet visible adsorption strength or peak position of the second mixing solution relative to that of the first mixing solution, wherein the copper ions are divalent copper ions. The method disclosed by the invention is simple and is flexible in design, free from a large-scale instrument, high in sensitivity and selectivity, strong in stability, good in reproducibility of the detecting result, and low in cost.

The invention discloses a preparation method, a product and application of a CuS / GO / MWCNTs composite nanoparticle modified electrode. The method includes the steps that a multi-wall carbon nanotube isactivated, wherein the multi-wall carbon nanotube is activated in an H2SO4 / HNO3 mixed solution, diluted, filtered and dried; a CuS / GO / MWCNTs composite material is prepared, wherein the activated multi-wall carbon nanotube is weighed and dissolved in water, graphene oxide colloidal sol is added, a uniform solution is obtained through ultrasonic dispersion, copper nitrate, polyvinylpyrrolidone andthiourea are added, stirring is performed, heating is performed for a reaction, after the reaction is ended, cooling, rinsing and drying are performed, and the CuS / GO / MWCNTs composite material is obtained. With the CuS / GO / MWCNTs composite nanoparticle modified electrode, the effect of detecting hydrogen peroxide is quite good, the threshold of detection is 0.6 microns, the linear detection range is 0.45-60 millimeters, the application potential is lower than 0.31 V, and the detection sensitivity is up to 386 microamperes / {millimeter*centimeter <2>}.

The invention provides a noninvasive biopsy virus detection method based on high throughput gene sequencing. The method can carry out DNA sequencing and RNA sequence in parallel and thus precisely determines the biological composition and structure of viruses in patients. The method can maximally avoid the interference of nucleic acid of host cells, effectively reduce the cost of sequencing, and is capable of detecting multiple unknown crossed viruses at the same time. 80 DNA tagged connectors are designed, related reagents are assembled to form a library so as to construct a kit, and if the throughput allows, the kit can perform sequencing on 80 samples in parallel. The experiment design is strict, the automation degree is high, the virus identification can be finished in batches within 24 hours, the requirements of scientific research and clinical detection can be met in different levels, and references are provided for clinical diagnosis and prescription of diseases related with virus infection.

The invention discloses a molecular logic gate construction method based on interaction between cyanine dyes and metal ions. The method comprises the following steps: taking a cyanine dye solution as a template; taking Tris-HCl buffer solutions with different pH values and metal ion solutions as two parallel input signals, and taking the normalized result of absorbance of cyanine dye H-aggregates between 510 nm-520 nm or absorbance of J-aggregates between 650 nm-665 nm as output signals; setting a threshold value to be 0.03-0.3; and when the normalized result is larger than the threshold value, output being 1, and when the normalized result is smaller than the threshold value, output being 0, so that basic Boolean logic gates of an "OR" gate, a " NOR " gate and an "AND NOT " gate are constructed. The constructed molecular logic gates are good in circuit performance, high in sensitivity, large in switch ratio and easier to distinguish; the threshold value can reach 0.3; the output signals are easy to detect; and dependence on detection instruments is small, and detection can be realized through an absorption spectrometer.

The invention discloses a bladder cancer mutation gene specific primer, kit and library construction method. A mode of unilateral enrichment-single molecule specific primer (single primer) is used foramplifying sub enrichment technologies for the first time; the application scope of the primer is expanded, the use amount of an effective template is increased, especially the detection limit for detecting low-frequency mutation samples is greatly improved; and secondly, a single molecule specific primer is composed of specific sequences and sequencing sequences, the specificity and the primer use ratio of multiple PCR can be effectively provided. The bladder cancer mutation gene specific primer, kit and library construction method applies the technology to the field of bladder cancer tumormutation gene detection, prepares corresponding reagents, can detect the mutation condition of tumor genes related bladder cancer efficiently and sensitively, and provides guidance for clinical application.

The invention discloses a method for detecting L-cysteine based on a calcium-metal organic framework material as a fluorescent probe. The invention firstly uses the lead chloride as a quenching agentto realize the fluorescence quenching of the Ca-MOFs complex, and then adding L-cysteine to achieve the fluorescence recovery effect on a quenching system, thereby indirectly determining the L-cysteine content in the system. The fluorescent probe Ca-MOFs complex used in the invention is a porous coordination polymer material with good water solubility, high chemical stability and low toxicity, isbased on Ca(NO3)2.4H2O as an inorganic ion node, uses rigidly symmetric (1,1':4',1'-terphenyl-3,3',5,5'-tetracarboxylic acid) as an organic bridging ligand, and uses a simple "one-pot" solvothermal technical means to be prepared and synthesized. The chemical formula of the fluorescent probe Ca-MOFs complex is {[Ca1.5(HL1)(DMF)2].DMF}. The method further discloses the use of the metal organic framework material as the fluorescent probe for the detection and analysis of L-cysteine and the preparation process of the Ca-MOFs complex crystal material.

The invention relates to an amphoteric carboxylic acid three-dimensional metal coordination polymer, and a preparation method and application thereof. The invention specifically discloses a water-soluble amphoteric carboxylic acid three-dimensional metal coordination polymer, wherein the main ligand of the three-dimensional copper coordination polymer is N-(3,5-dicarboxylbenzyl)-(3-carboxyl)-pyridine bromide; the auxiliary ligand of the polymer is 1,2-bis(4-pyridyl)ethylene; and central atom of the polymer is copper. According to the invention, raw materials are widely and easily available; the preparation method is simple in process, mild in reaction conditions and good in repeatability; and the amphoteric carboxylic acid three-dimensional metal copper coordination polymer has good water-solubility, can be successfully applied to detection of nucleic acid sequences of AIDS, SUDV, dengue viruses and the like, has the advantages of rapidness, convenience, high efficiency and sensitivity, and shows good application prospects in detection of related diseases.

The invention provides a method for constructing a half adder and a half subtracter based on the interaction between a cyanine dye and metal ions, and the method is characterized by comprising the steps: a cyanine dye solution and DNA double strands are taken as templates, Tris-HCl buffer solutions with different pH values and metal ion solutions are taken as two parallel paths of input signals, the DNA double strands are induced into four-strand structures under regulation and control of the Tris-HCl buffer solutions and the metal ions, the cyanine dye interacts with the DNA four-strand structure through non-covalent bond acting force to generate spectral signals, and the ultraviolet absorption values and / or fluorescence intensities of the cyanine dye are taken as output signals to construct the half adder or half subtracter. The half adder or half subtracter constructed by the scheme has good molecular logic circuit property, high sensitivity, large on off ratio, easy differentiation and low threshold of 0.3. The detection of the output signals is easy and can be realized by an absorption / fluorescence spectra instrument, and the ion concentration of a solution can be detected efficiently, sensitively, simply and rapidly.

The invention belongs to the technical field of biological detection sensors, and discloses a hydrogen sulfide colorimetric sensor based on a G4-Cu<2+> mimic enzyme system. In MES (Morpholineethanesulfonic acid) buffer solution, independent Cu<2+> does not have an obvious catalytic function on H2O2 oxidation TMB (tetramethylbenzidine); after human telomere DNA (deoxyribonucleic acid) is added, human telomere can form a G-quadruplex, and meanwhile, the human telomere can be combined with Cu<2+> to form a G4-Cu<2+> mimic enzyme compound, and catalytic capacity is greatly improved; after H2S is met, Cu<2+> and H2S have good specificity, and CuS precipitates are generated so as to lower the enzyme catalytic capacity of G4-Cu<2+>; and along with the increasing of H2S concentration, TMB color development is gradually changed into colourless from blue. By use of the sensor, the color change of the system of the sensor can be used for qualitatively and quantitatively detecting H2S. Due to theadding of the G-quadruplex, the detection sensitivity of a sensing system for H2S is improved, the detection limit of 7.5nM is realized, and the sensing system has good selectivity for H2S.

The invention provides a construction method for an encoder and a decoder. The method comprises the step of constructing the encoder or the decoder in the manner of taking a cyanine dye solution or cyanine dye solution and double-chain DNA as a template, taking H+, potassium ions, sodium ions and single-chain DNA as input factors, taking a Tris-HCl buffering solution in concentration of (1-100)*10<-3> mol / L and pH of 7.0-9.0 as an one-path input signal, taking the input factors or the combination thereof as parallel input signals and taking diploid or a cyanine dye aggregation state induced by the input factors as an output signal. The encoder and the decoder are high in sensitivity, are at high switch ratio and are easily distinguished; the threshold value is below 0.3; the output signal is easily detached; the dependency on the detecting instrument is less; an absorbing / fluorescence detector can be used for realizing detection; the ionic concentration in the solution can be efficiently, sensitively, simply and quickly detected.

The invention relates to a dopamine and resorcinol reaction product as well as a preparation method and application thereof, and belongs to the technical field of analytical chemistry. According to the invention, a fluorescent probe with good water solubility is mainly formed through a reaction between dopamine and resorcinol. The probe disclosed by the invention is overlapped with the absorption wavelength (430-550 nm) of Cr<6+>, an inner filtering effect is generated between Cr<6+> and a reaction product of dopamine and resorcinol provided by the invention, the fluorescence intensity is reduced along with the increase of the concentration of added hexavalent chromium, and a good linear relationship is kept; meanwhile, ascorbic acid can reduce Cr<6+> into Cr<3+>, so that the inner filter effect between Cr<6+> and the reaction product is destroyed, and the fluorescence intensity of the reaction product of dopamine and resorcinol, which is reduced due to the influence of Cr<6+>, is recovered. Therefore, the dopamine and resorcinol reaction product provided by the invention has a green, efficient and sensitive detection effect on hexavalent chromium ions (Cr<6+>) and ascorbic acid.

A III-V semiconductor pixel X-ray detector, including an absorption region of a first or a second conductivity type, at least nine semiconductor contact regions of the second conductivity type arranged in a matrix along the upper side of the absorption region, and optionally a semiconductor contact layer of the first conductivity type, a metallic front side connecting contact being arranged beneath the absorption region, and a metallic rear side connecting contact being arranged above each semiconductor contact region, and a semiconductor passivation layer of the first or the second conductivity type. The semiconductor passivation layer and the absorption region being lattice-matched to each other. The semiconductor passivation layer being arranged in regions on the upper side of the absorption region. The semiconductor passivation layer having a minimum distance of at least 2 μm or at least 20 μm with respect to each highly doped semiconductor contact region.

The invention discloses a method for identifying and detecting 5-hydroxymethyl cytosine (5hmC) and 5-formyl cytosine (5fC) in DNA and belongs to the fields of molecular biology, nucleic acid chemistryand epigenetics, The method includes: adding to-be-detected DNA into a mixed solution containing potassium perruthenate and alkali, performing reaction under an ice water bath condition to allow the5hmC in the DNA to be oxidized into the 5fC; purifying the DNA after the reaction, adding into a hot alkali solution to perform heat-preservation reaction to achieve DNA cleavage, and performing gel analysis to measure the total number and site of the 5hmC and 5fC in the DNA; directly adding the to-be-detected DNA into the hot alkali solution without potassium perruthenate oxidation to perform heat-preservation reaction to achieve DNA cleavage, and performing gel analysis to measure the total number and site of the 5fC in the DNA; comparing the two results to obtain the number and site of the5hmC and 5fC in the DNA. By the method high in sensitivity and wide in application range, the defects that existing detection methods are high in equipment requirements, complex in operation and the like.

The invention provides a hydrogen peroxide detection method, which comprises: S1, mixing valine and secondary water, and carrying out hydrothermal reaction to prepare carbon quantum dots; S2, preparing a detection solution containing carbon quantum dots and TMB; S3, taking a certain amount of the detection solution, adding H2O2 with different concentrations into the detection solution, carrying out reaction for a period of time, then measuring the absorbance, and making a standard curve of the H2O2 concentration and the absorbance; and S4, taking a to-be-detected sample containing H2O2, adding the to-be-detected sample containing H2O2 into a same amount of the detection solution, carrying out reaction for the same time, measuring the absorbance, and calculating the content of H2O2 in the to-be-detected sample according to the standard curve. The method can effectively detect the concentration of H2O2.

The invention discloses an SNP (Single Nucleotide Polymorphism) marker and application thereof. Wherein the SNP marker is T or C of the 35th basic group from the 5'terminal of the nucleotide sequence shown in SEQ ID NO: 1, or the SNP marker is A or G of the 46th basic group from the 5 'terminal of the nucleotide sequence shown in SEQ ID NO: 1. The SNP marker is closely related to the rice variety and can be effectively used for qualitatively or quantitatively detecting the rice variety.

The invention discloses an SNP (Single Nucleotide Polymorphism) marker for oryza sativa var. Virens and The SNP marker is T or C of the 64th basic group from the 5'terminal of the nucleotide sequence shown in SEQ ID NO: 1. The SNP marker is closely related to the rice variety and can be effectively used for qualitatively or quantitatively detecting the rice variety.

The invention discloses a new method for detecting guanines in a non double-chain region in DNA by using a mixed aqueous solution of hydrogen peroxide and potassium tungstate. The method comprises the following steps: enabling hydrogen peroxide and potassium tungstate to selectively have oxidization reaction with guanine in DNA and then treating with piperidine so that oxidized DNA is fractured; and carrying out polyacrylamide gel electrophoresis experiment so that nucleic acid fracture zones with different thicknesses are separated one by one, thus obtaining the positions and number of all guanines. The method can be used for quickly, effectively and sensitively detecting guanines in the non double-chain region.

The invention provides a mobile steam safety valve thermal state test platform, which comprises a test terminal and a pressure relief test mechanism, the pressure relief test mechanism comprises a left closed cylinder, a middle movable closed cylinder and a fitting mechanism, and one end of the middle movable closed cylinder is provided with an annular closed groove. A middle movable sealing cylinder of the pressure relief testing mechanism can slide back and forth between a left sealing cylinder and an attaching half pipe, when the middle movable sealing cylinder and the attaching half pipe are closed under the cooperation effect of an annular sealing groove and a sealing half inserting pipe, a safety valve can be completely sealed inside, and at the moment, the safety valve can be sealed to be closed as long as the safety valve relieves pressure. The middle movable sealing cylinder is quickly separated from the fitting half pipe, and meanwhile, the real-time thermal state of the safety valve and the temperature during pressure relief can be detected, so that the purpose of testing the thermal state of the safety valve is achieved.

The invention discloses an SNP (Single Nucleotide Polymorphism) marker and application thereof. Wherein the SNP marker is T or C of the 23rd basic group from the 5'end of the nucleotide sequence shown in SEQ ID NO: 1, or the SNP marker is A or G of the 43rd basic group from the 5 'end of the nucleotide sequence shown in SEQ ID NO: 1. The SNP marker is closely related to the rice variety and can be effectively used for qualitatively or quantitatively detecting the rice variety.

The invention provides a rapid detection kit for heavy metal Al < 3 + > and an application method of the rapid detection kit for heavy metal Al < 3 + >. The application method comprises the following steps: (1) verifying and evaluating the activity of monatomic cerium (Single atom Ce-N-C, SACe-N-C) nano-enzyme phosphatase (PPA-like), and (2) constructing a detection system of the rapid detection kit. According to the method, Al < 3 + > can react with oxygen atoms in a monatomic cerium nano-enzyme structure to form an Al-O bond, so that the activity of monatomic cerium nano-enzyme phosphatase is remarkably reduced, and rapid and efficient detection of Al < 3 + > in a system can be realized within 4 minutes.

The invention provides a method for detecting 5-methylcytosines in nucleic acid. The method includes the concrete steps that first, a nucleic acid chain with a fluorescent label is treated with sodium hydrogen sulfite, all cytosines on the nucleic acid chain will change into uracils, but the 5-methylcytosines are not influenced; then, a compound 1 is specifically reacted with the 5-methylcytosines, but is not reacted with the uracils, thymines, guanines and adenines; due to the fact that thermal piperidines can rupture damaged basic group portions in the nucleic acid, the positions and number of the 5-methylcytosines can be clearly seen through a nucleic acid strip of denatured polyacrylamide gel after the nucleic acid chain reacted with the compound 1 is treated with the thermal piperidines, wherein the structural formula of the compound 1 is shown in the specifications.

The invention discloses a preparation method of a dual-signal electrochemical sensor for rapidly and selectively detecting sunset yellow, belonging to the field of electrochemical sensors. Including: (1) Preparation of PEI-GAs@AuNPs / SH-β-CD composite; (2) Preparation of PEI-GAs@AuNPs / SH-β-CD composite electrode; (3) Linear sweep voltammetry detection. The invention can not only overcome the interference of false positive or negative results of the single-signal electrochemical sensor and the interference signal of background current, but also can detect the food additive sunset yellow efficiently and sensitively, and improve the sensitivity and accuracy.