46results about How to "Low detection concentration" patented technology

The invention discloses a kit for detecting pig epidemic diarrhea viruses, pig transmissible gastroenteritis viruses and pig rotaviruses. The kit comprises primer pairs shown by SEQ ID NO:1-2, SEQ ID NO:3-4 and SEQ ID NO:5-6 for respectively performing specific amplification on the pig epidemic diarrhea viruses, the pig transmissible gastroenteritis viruses and the pig rotaviruses. The invention also discloses applications of the primer pairs shown by the SEQ ID NO:1-2, the SEQ ID NO:3-4 and the SEQ ID NO:5-6 in preparation of reagents for detecting the pig epidemic diarrhea viruses, the pig transmissible gastroenteritis viruses and the pig rotaviruses. The detection kit disclosed by the invention can be used for accurately and effectively detecting the pig epidemic diarrhea viruses, the pig transmissible gastroenteritis viruses and the pig rotaviruses, and is strong in specificity, high in sensitivity, short in time consumption, rapid in detection and good in application prospect.

The invention adopts oligonucleotide aptamers for identifying special tripeptide sequence KAI, GEL, DGI and LAS, extanding oligonucleotide aptamers by Structure-switch and phosphorylation decorating 5' end thereof, synthetising four connexons; connecting oligonucleotide aptamers combinated with target albumen through proximity dependent DNA Ligation technique as chain ringlike DNA; amplifying detecting signals via rolling-circle DNA duplicate method; the technique can detect target albumen sensitively, the least detecting concentration can get nM level; this method with flexibility can adjust according needed numbers of ligand; can detect albumen composite, provide sensitive detecting method for chip technique using oligonucleotide aptamers as ligand.

The invention discloses a two-photon fluorescent probe as well as a preparation method and application thereof. The two-photon fluorescent probe takes coumarin and rhodamine as a matrix. The structure of the two-photon fluorescent probe is described in the specification. Molecules of the two-photon fluorescent probe show relatively high selectivity and sensitivity in a system in which palladium ions (II) and other positive ions coexist. A cytotoxicity test shows that the two-photon fluorescent probe disclosed by the invention has hardly any toxic effect on cells, and a two-photon fluorescence microscopy imaging experiment shows that the two-photon fluorescent probe has good HeLa cell permeability and is applicable to detection of distribution of palladium ions (II) in cells.

The invention discloses a cavity structure array assembled by silver nanoparticles as well as a preparation method and application of the cavity structure array. The structure is composed of a conductive substrate and a silver nanostructure on the conductive substrate, the silver nanostructure is a porous film formed by stacking silver nanoparticles, and holes are of spherical cavity structures arranged in order; and the preparation method comprises the following steps that silver nitrate powder, citric acid powder, ethylenediaminetetraacetic acid powder, sodium sulfite powder and dipotassiumphosphate powder are dissolved in water to obtain an electrolyte, and then the conductive substrate sputtered with the gold film with the thickness of 15-30 nm and covered with one or more layers of polystyrene microsphere crystal templates in sequence serves as a cathode, a graphite flake serves as an anode to be placed in an electrolyte for electro-deposition, and a target product is prepared onthe conductive substrate. The prepared cavity structure array assembled by the silver nanoparticles has three-dimensionally distributed SERS hot spots, the SERS sensitivity is high, rhodamine 6G withthe concentration as low as 1 fmol / L can be detected, and the cavity structure array can be easily and widely commercialized to serve as an active substrate for surface-enhanced Raman scattering.

The invention provides a double droplet type digital PCR absolute quantification kit for AIV H7N9 subtypes. The double droplet type digital PCR absolute quantification kit comprises two pairs of specific primer pairs and two specific probes used in cooperation with specific primers, and nucleotide sequences are as shown in SEQ ID No.1-6 respectively. According to the double droplet type digital PCR absolute quantification kit, AIV H7N9 subtypes can be detected quickly, specifically and sensitively through a digital PCR instrument, and the detection sensitivity reaches one copy. The double droplet type digital PCR absolute quantification kit is simple in use method, low in cost, capable of detecting the AIV H7N9 subtypes quickly, directly and quantitively without a standard curve, very applicable to disease supervision, on-site emergency detection and clinical sample detection, and suitable for application and popularization in a wide range.

The invention discloses an electrochemical sensor for simultaneously detecting PAT and OTA, a preparation method and a detection method. The electrochemical sensor comprises a working electrode, a reference electrode and a counter electrode, and the surface of the working electrode is sequentially coated with an AuNPs-BP nano composite material layer and an identification sensitive layer for identifying an object to be detected; the AuNPs-BP nano composite material layer is coated on the surface of the working electrode, and the identification sensitive layer is coated on the surface of the AuNPs-BP nano composite material layer; the identification sensitive layer comprises a PAT aptamer chain, a PAT complementary chain, an OTA aptamer chain and an OTA complementary chain. The electrochemical sensor can detect PAT and OTA at the same time, detection of two target objects is achieved through the same electrochemical sensing platform, and the detection concentration is low.

The invention provides an application of an AlGaAs / GaAs HEMT biosensor in detection of an IL-1beta potential inhibitor, and the application is characterized in that the IL-1beta-AlGaAs / GaAs HEMT biosensor is constructed by using an AlGaAs / GaAs HEMT device as a transducer and using interleukin 1beta protein modified on the HEMT device as an identification element through self-assembly of a single layer, the IL-1beta-AlGaAs / GaAs HEMT biosensor is used for identifying the IL-1beta potential inhibitor, and the IL-1beta-AlGaAs / GaAs HEMT biosensor is used for detecting the IL-1beta potential inhibitor. The detection concentration is as low as pM level, the detection range covers five orders of magnitude, and the method has high sensitivity and strong specificity.

The invention discloses a two-photon fluorescent probe as well as a preparation method and an application thereof. The structure of the two-photon fluorescent probe is shown in the specification. The two-photon fluorescent probe presents relatively high selectivity and high sensitivity in a coexisting system of aminothiopropionic acid or homocysteine and other amino acids. The cytotoxicity test shows that the two-photon fluorescent probe almost has no toxicity on cells. The two-photon fluorescent microscopic imaging experiment shows that the two-photon fluorescent probe is good in permeability on 293FT cells. The two-photon fluorescent probe is suitable for detecting the distribution of amino acid micromolecules in the cells.

The invention discloses a kit for detecting pig epidemic diarrhea viruses, pig transmissible gastroenteritis viruses and pig rotaviruses. The kit comprises primer pairs shown by SEQ ID NO:1-2, SEQ ID NO:3-4 and SEQ ID NO:5-6 for respectively performing specific amplification on the pig epidemic diarrhea viruses, the pig transmissible gastroenteritis viruses and the pig rotaviruses. The invention also discloses applications of the primer pairs shown by the SEQ ID NO:1-2, the SEQ ID NO:3-4 and the SEQ ID NO:5-6 in preparation of reagents for detecting the pig epidemic diarrhea viruses, the pig transmissible gastroenteritis viruses and the pig rotaviruses. The detection kit disclosed by the invention can be used for accurately and effectively detecting the pig epidemic diarrhea viruses, the pig transmissible gastroenteritis viruses and the pig rotaviruses, and is strong in specificity, high in sensitivity, short in time consumption, rapid in detection and good in application prospect.

This invention is a manufacturing method of the sensitive material, formaldehyde sense organ made by sensitive material and the sense organ. It relates to a sensitive material that can detect formaldehyde, sense organ that can measure the viscosity of formaldehyde and the manufacturing method. This invention settles the problem of long-time response and recovery, high working temperature of the current sense organ to detect formaldehyde. The general formula of the sensitive material is B2-aAbO3, A is Sn,Pb,Ti or Zr, B is Mo, W,Cr or Mn, 0<a=b<1. The sense organ consists of explosion-prevention net, two heating probes, four detecting probes, thick-film sense organ, probe basis, connecting work and heating device. This invention has such merits as low detecting viscosity of formaldehyde, low working temperature, short response time and high stability of the sense organ.

The invention discloses a method of determining anti-thrombin activity of hirudin. The method includes: allowing hirudin having certain mass and containing unknown activity to react with sufficient thrombin, allowing cross-linking reaction under the action of cross-linking agent BS3 to obtain a first mixture system containing the hirudin, the thrombin and a hirudin-thrombin compound after completion of cross-linking, performing optical density scanning after electrophoresis, acquiring mass of the hirudin-thrombin compound according to protein band density of the hirudin-thrombin compound on the basis of a control having known protein band density, combining the hirudin and the thrombin according to a mass ratio: 1:5 so as to obtain the hirudin-thrombin compound so as to acquire mass of effective thrombin participating in reaction, and performing calculating according to the mass fraction of the effective thrombin in the thrombin and the mass of the hirudin so as to obtain an activity value of the hirudin, having the certain mass, in inhibiting the thrombin, namely an anti-thrombin activity value of the hirudin. The method is simple to operate, good in accuracy and low in investment and has low equipment requirements.

The invention relates to a method for detecting silver ions in drinking water, and aims to solve the technical problem that low detecting concentration is difficult to be reached as fluorescence detection is performed by the aid of a quenching or enhancing method. The detecting method includes the steps: firstly, dissolving bibenzoyl tartaric acid coordination compounds into N, N'-dimethyl formamide solvents to prepare into mixed liquid; secondly, mixing the drinking water and the mixed liquid according to the volume ratio of 1:1, irradiating mixture by the aid of ultraviolet light by the aid of the wave length ranging from 320nm to 324nm, observing a solution color. The solution color changes into red from white when the concentration of the silver ions in the drinking water is higher than 0.05ppm. The method is simple to prepare, low in detecting concentration, the silver ions in the drinking water are detected by the aid of white-light materials, the color of the white-light materials changes into red when the concentration of the silver ions is equal to or higher than 0.05ppm, and detection limit meets world health organization standards.

The invention discloses a switch-type ferric ion fluorescence probe and a preparation method thereof. Rhodamine B is adopted as a matrix of the switch-type ferric ion fluorescence probe, and the structural formula of the switch-type ferric ion fluorescence probe is as follows (refer to the Specification). According to the invention, fluorescence probe molecules demonstrate higher selectivity and sensitivity in the concomitant system of ferric ions and other positive ions; a fluorescence development experiment shows that the fluorescence probe molecules have excellent cell penetrability, are nontoxic for cells, and can be used for detecting the concentration and distribution of ferric ions in cells.

The invention discloses a cavity structure array assembled by silver nano particles and a preparation method and application thereof. The structure is composed of a conductive substrate and a silver nanostructure on it, wherein the silver nanostructure is a porous film stacked with silver nanoparticles, and the holes are a spherical cavity structure arranged in an orderly manner; the preparation method is to firstly combine silver nitrate powder, lemon Acid powder, ethylenediaminetetraacetic acid powder, sodium sulfite powder and dipotassium hydrogen phosphate powder are dissolved in water to obtain an electrolyte solution; then a 15-30nm thick gold film is sequentially sputtered and covered with one or more layers of polystyrene microsphere crystals The conductive substrate of the template is used as the cathode, and the graphite sheet is used as the anode to be electrodeposited in the electrolyte, and the target product is prepared on the conductive substrate. The prepared silver nanoparticle-assembled cavity structure array has three-dimensionally distributed SERS hot spots, high SERS sensitivity, capable of detecting Rhodamine 6G at concentrations as low as 1 fmol / L, and is extremely easy to be widely commercialized as a surface-enhanced Raman scattering activity. base.

The invention discloses a two-photon fluorescent probe and its preparation method and application, wherein the two-photon fluorescent probe is based on coumarin and rhodamine, and its structure is represented by the following: (Ⅱ) In the system coexisting with other cations, it exhibits higher selectivity and sensitivity. Cytotoxicity tests show that the present invention has almost no toxic effect on cells, and two-photon fluorescence microscopic imaging experiments show that the present invention has good permeability to HeLa cells and is suitable for detecting the distribution of palladium ions (II) in cells.