165 results about "Ochratoxin A" patented technology

The invention discloses a method for detecting ochratoxin A by using an electrochemical luminous adaptor sensor, which belongs to the technical field of electrochemical luminous sensors and is used for detecting the ochratoxin A content of wheat, grains, feeds and products thereof. The method is based on the ochratoxin A specificity identification by an adaptor and an electrochemical luminous reaction of hydrogen peroxide (H2O2) and isoluminol (ABEI) under an alkaline condition. The method comprises the following steps of: modifying the surface of a naked gold electrode by using gold nanoparticles to amplify an electrochemical luminous signal; modifying the surface of a working electrode by using single stranded DNA, and modifying the electrode surface with the adaptor marked with the isoluminol (ABEI) by base pairing; adding the hydrogen peroxide (H2O2) to detect the electric luminous signal; and establishing a quantitative detection standard curve of the ochratoxin A according to the ratio of the strength of the electrochemical luminous signal to the concentration of the ochratoxin A. The invention aims to provide a high-sensitivity and high-operability ochratoxin A quantitative detection method.

The invention discloses an ochratoxin A fluorescence detection test strip and application thereof, relates to a method for detecting ochratoxin A by using a fluorescence test strip of a quantum dot-labeled aptamer, and belongs to the technical field of fluorescence detection. The test strip comprises a lower water-absorbent pad (1), a quantum dot-coupled Aptamer 1 (2), a streptavidin-biotin-Aptamer 2 (3), a streptavidin-biotin-Aptamer 3 (4), an upper water-absorbent pad (5), a nitrocellulose membrane (6) and a bottom plate (7). By using a chromatography one-step competition principle, the test strip semiquantitatively detects ochratoxin A residue quantity in a semiquantitative detection sample through upper and lower colorimetric belts thereof, rapidly and accurately detects whether the sample contains the ochratoxin A within 15 min to determine whether the ochratoxin A is overproof, can meet the requirement of food safety on the detection of the ochratoxin A residue quantity, and is suitable for feeds, meat producing plants and government detection mechanisms; and compared with the prior art, the test strip has the characteristics of convenient use, economy, rapidness, simple manufacturing and low cost.

The invention relates to an electrochemical lateral-flow immunity quantitative test paper sensor based on microclearance array electrode, and a method thereof used for detecting biological toxins such as ochratoxin A and fumonisin B1. The sensor includes two parts, namely, immune chromatographic analysis test paper strip and electrochemical detecting part. The fast detecting test paper sensor has strong specificity, can realize quantitative detection, can be used at the temperature between 4 and 40 DEG C, and the result can be observed after ten minutes, thus being suitable for units or individuals to quickly detect ochratoxin A and fumonisin B1 in animal derived food samples, and being expected to become an effective technical means for the field screening of ochratoxin A and fumonisin B1 in food and feed samples.

The invention discloses a construction method and application of SERS aptasensor based on nano-assembly structure. The method comprises the following steps: respectively modifying surfaces of gold nano-rod and gold nano-particle with two kinds of DNA complementary with an ochratoxin A aptamer segment part to form two nano-probes; then assembling an assembly nano-structure under complementary pairing connection of the two nano-probes and the DNA aptamer, and labeling a Raman beacon molecule on the assembly nano-structure; and adding a solution of a substance for detecting, and detecting the concentration of the assembly nano-structure by utilizing the fact that the SERS signal intensity of the assembly nano-structure is influenced by the substance for detecting. By adopting the method, reaction in a liquid environment is uniform, the detection has high sensitivity and high specificity, only one-step reaction is required, and the operation is simple.

The invention discloses a test strip for testing ochratoxin A and application of the test strip. The test strip comprises a sample absorbing pad (1), a conjugate releasing pad (2), a reaction film (3), a water absorbing pad (4) and a bottom board (7), wherein a test line (5) coated with an ochratoxin A hapten-carrier protein conjugate, and a quality control line (6) coated with an anti-goat anti-mouse antibody are arranged on the reaction film, and the conjugate releasing pad (2) is sprayed an ochratoxin A monoclonal antibody- colloidal gold marker. The invention further provides a method for testing the ochratoxin A residues in grain and feed by applying the test strip for the ochratoxin A. The test strip provided by the invention has the characteristics of simple operation, high sensitivity, high testing speed, low cost and the like, and therefore, the test strip is suitable for the screening and the on-site supervision of a large number of samples.

The invention discloses a homogeneous-phase rapid detection method of ochratoxin A based on nucleic acid chimeric dye fluorescence quenching. The homogeneous-phase rapid detection method comprises the following steps: (1) forming an ochratoxin A nucleic acid aptamer and a nucleic acid chimeric dye fluorescence composite; and (2) specifically recognizing ochratoxin A by the ochratoxin A nucleic acid aptamer. According to the invention, the OTA (ochratoxin A) detection method is constructed by taking the ochratoxin A nucleic acid aptamer as a molecule recognition element and taking the nucleic acid chimeric dye as report molecule; the cost for detecting OTA fungaltoxin is reduced greatly; the detection method is good in reproducibility and high in specificity, is simple and convenient to operate and can detect a great quantity of samples in parallel. The homogeneous-phase rapid detection method provided by the invention can detect OTA only for 5-10 minutes after the ochratoxin A nucleic acid aptamer and the nucleic acid chimeric dye fluorescence composite are formed in advance.

The invention relates to a nucleic acid aptamer for specifically identifying ochratoxin A and a preparation method thereof. The sequence of the single-chain DNA (deoxyribonucleic acid) aptamer is a sequence I. The nucleic acid aptamer for specifically identifying the ochratoxin A is characterized in that by adopting the index enrichment ligand system advancing technology based on graphene oxide separation, and in-vitro screening, the single-chain oligonucleotide aptamer with high affinity and ability of specifically identifying the OTA toxin is obtained; the specificity is good, the stability is high, the cost is low, the synthesizing and modifying are easy, the convenience in use is realized, the toxicity is avoided, and the like; the nucleic acid aptamer can be applied to studying of biological sensors and solid-phase affinity purifying columns based on the nucleic acid aptamer, and analyzing methods for quick detection on agricultural products, and the like.

The invention discloses a method for detecting ochratoxin A (OTA) based on luminescence resonance energy transfer between an up-conversion luminescence nano-material and gold nano-rods. The method is used for detecting the content of OTA in wheat and products thereof. The up-conversion luminescence nano-material (NaYF4:Yb0.286, Er0.0286) and OTA aptamers are connected to form an energy donor probe, then the energy donor probe and an energy receptor probe form a nano-composite based on the base complementary pairing principle, the phenomenon of luminescence resonance energy transfer (LRET) occurs, and the purpose of up-conversion luminescence quenching is achieved, wherein the energy receptor probe is formed by the gold nano-rods modified by aptamer complementary oligonucleotide single strands, and the aspect ratio of the gold nano-rods is about 2.5. When OTA exists in a detection system, OTA and OTA aptamers are specifically bound, and therefore double strands are melted; OTA can be quantitatively detected by monitoring the up-conversion luminescence signal intensity at 657 nm, the linearity range is 0.05-100 ng/mL, and the detection limit is 0.027 ng/mL. The method has the advantages of being high in sensitivity, fast, simple and convenient to implement when used for detecting OTA. In addition, the method is applied to detecting beer or wheat samples, and results are accurate and reliable.

The invention discloses an ultra-sensitive detection method of ochratoxin A based on a gold core-silver satellite chiral assembly body, and belongs to the field of analytical chemistry. The method mainly comprises the following steps: (1) synthesizing gold nanoparticles with the particle size of 35 nm; (2) synthesizing silver nanoparticles with the particle size of 8 nm; (3) modifying aptamers on the gold nanoparticles; (4) modifying part of complementary sequences of aptamers on the silver nanoparticles; (5) assembling a gold core silver satellite structure; (6) performing circular dichroism spectrum detection, and creating a standard curve of gold and silver chiral signal superposition and ochratoxin A concentration. The invention provides a method for detecting ochratoxin A by a chiral signal of the gold core silver satellite structure. Compared with a conventional detection method, the method provided by the invention is low in cost, high in sensitivity, convenient and quick, and has a very good practical application prospect.

This invention provides a monoclonal antibody specific to ochratoxin A and methods of assaying the level of ochratoxin A in food and feed.

The invention discloses an immunosorbent comprising a solid-phase carrier and an antibody coupled with the solid-phase carrier. The antibody comprises a monoclonal antibody secreted by a hybridoma cell line CGMCC NO.5504 and a monoclonal antibody secreted by a hybridoma cell line CGMCC NO.5505. The invention also provides a kit comprising the immunosorbent or an immunoaffinity column. Also, the invention provides applications of the immunosorbent, immunoaffinity column, and kit in detecting aflatoxins, sterigmatocystin, zearalenone congeners and ochratoxin A. The invention specifically provides separation and detection methods. According to the invention, the specific monoclonal antibodies with stable performances are developed, such that simultaneous purification and detection of 6 aflatoxins, sterigmatocystin, 6 zearalenone congeners and ochratoxin A are realized.

The invention discloses a composite affinity column for purifying 3-acetyl deoxynivalenol, aflatoxin, ochratoxin A and zearalenone, a preparation method and an application thereof. According to the invention, by employing 4% of cylindrical agarose gel as a solid phase carrier, agarose gel and an antibody are coupled to form an immunoadsorbent, and filling in a column to prepare the immunization affinity column. When a sample containing 3-acetyl deoxynivalenol, aflatoxin, ochratoxin A and zearalenone passes through the immunization affinity column, 3-acetyl deoxynivalenol, aflatoxin, ochratoxin A and zearalenone can be specifically adsorbed by the immunoadsorbent, other impurities flows out of the immunization affinity column, then methanol is used for eluting 3-acetyl deoxynivalenol, aflatoxin, ochratoxin A and zearalenone from the column, so that the sample can be better purified.

The present invention belongs to the field of biosensing technologies, and relates to a method for preparing a ratio electrochemical aptamer sensor for detecting ochratoxin A, and the method is used for detecting the ochratoxin A (OTA). The ratio sensing policy is constructed by sequentially modifying ferrocene marked complementary DNA (Fc-cDNA), ochratoxin A aptamer (Aptamer) and auxiliary complementary DNA (hDNA) on a gold electrode, double current signals IFc and IMB (which are respectively oxidized electric currents of Fc and MB) are output by using a target-induced comformational change,and OTA is detected by using a ratio signal (IFc/IMB) quantization sum of IFc and IMB. The obtained ratio electrochemical aptamer sensor can implement highly sensitive and highly reliable detection onthe OTA, a detection linearity range is 10 pg/mL to 10 ng/mL, and a detection limit is 3.3 pg/mL. The present invention aims to develop a ratio electrochemical aptamer sensor that is high in sensitivity, good in selectivity, and high in reliability, and provide a reliable sensing platform for measuring OTA in an actual sample.

The present invention relates to an immunoadsorbent and a composite affinity column for purification of fumonisin B1, aflatoxin, ochratoxin A and zearalenone. The immunoadsorbent comprises a solid carrier and fumonisin B1, aflatoxin, ochratoxin A and zearalenone monoclonal antibodies coupled with the solid carrier, the fumonisin B1 monoclonal antibody is secreted from hybridoma cell line Fm7A11 with the preservation number of CCTCCNO.C201636, the hybridoma cell line Fm7A11 is preserved in CCTCC in March 29, 2016 in Wuhan University Wuhan China. The composite affinity column is loaded with the immunoadsorbent with the fumonisin B1, aflatoxin, ochratoxin A and zearalenone monoclonal antibodies, and is used for purification of the fumonisin B1, aflatoxin, ochratoxin A and zearalenone. The composite affinity column can be used for purification and detection of fumonisin B1, aflatoxin, ochratoxin A and zearalenone toxin samples.

A viewable gold nanorod test strip for rapid detection of ochratoxin A and a preparation method thereof relate to the technical field of ochratoxin A detection. The test strip is composed of a lining board and a sample pad, a gold nanorod tag binding pad, a coating film and a water absorption pad which are successively connected on the lining board. The gold nanorod tag binding pad is a glass fiber film or polyester film which carries gold nanorod labeled OTA antibody. The coating film contains an invisible detection line T line printed by ochratoxin A coupled protein solution and an invisible control line C line printed by goat anti mouse IgG solution. The sample pad of the test strip is inserted into a sample solution to be tested, a reaction is performed at room temperature for 15 min, and the result is determined according to the coloration condition of the detection line T and the control line C. According to the invention, ochratoxin A is detected based on the viewable gold nanorod test strip technology. The viewable gold nanorod test strip provided by the invention has characteristics of high sensitivity, short reaction time and cheap instrument and equipment, and is convenient and easy to use.

The present invention belongs to the field of materials science and modern separation and analysis, and relates to a preparation method and an application for a magnetic metal organic framework medium modified by a new nucleic acid aptamer. The method comprises the following steps of: firstly preparing nanoscale amino functional magnetic ferroferric oxide (NH2-Fe3O4); then adopting a hydrothermal synthesis method to obtain the magnetic metal organic framework medium; and finally adopting a coupling agent streptavidin as an intermediate to prepare the magnetic metal organic framework medium modified by an ochratoxin A nucleic acid aptamer (OTA Apt -MMIL-101). With adoption of reaction functionalization of ferroferric oxide and 3-aminopropyl triethoxysilane (APTES), OTA Apt-MMIL-101 is synthesized by the NH2-Fe3O4 and a metal organic framework 101 medium (MIL-101) synthetic agent under a condition of hydrothermal reaction through a chemical bonding method, is washed and is dried in vacuum. The OTA Apt-MMIL-101 disclosed by the present invention has good stability and high selectivity recognition performance, and is applicable to selective enrichment and separation of complex samples such as organisms, environment and food.

The invention discloses a Kluyveromyces marxianus C2 and a preparation method and an application thereof. The preservation number of the Kluyveromyces marxianus C2 is CCTCC NO: M2014059. The aflatoxin B1, zearalenone and ochratoxin A can be degraded by Kluyveromyces marxianus C2 and the biodegradation rate reaches more than 80%. The fermented Kluyveromyces marxianus C2 is put into toxin-contaminated liquid or solid food or feed matrix at a certain ratio to enable mycotoxins to be fast, safely and efficiently degraded and detoxified and can also be used for oral detoxification of animals. The strain disclosed by the invention has the advantages of low production cost and safe application and has wide application prospects.

Relating to the field of microorganisms, the invention discloses an inoculant, a feed or additive and a removal method for mycotoxins. The invention specifically discloses an inoculant, which includesat least two of mould, yeast and bacteria, wherein the bacteria can be at least one of brevibacterium, acinetobacter, rhodococcus and pseudomonas. Specifically, the inoculant can remove mycotoxins. The invention also discloses application of the inoculant in removal of mycotoxins, an additive containing the inoculant and a removal method for mycotoxins. According to the technical scheme, combineduse of at least two of the yeast, mould and bacteria can achieve simultaneous removal of ochratoxin A, fumonisins and T-2 toxin, and the removal efficiency of ochratoxin A and fumonisins is the highest.

The invention provides luteimonas sp for degrading alflatoxin B1 and ochratoxin A and application of the luteimonas sp and particularly provides a strain of difunctional efficient degrading bacteria (Luteimonas sp.) CW574 and application thereof in degrading low-pollution-concentration alflatoxin B1 and ochratoxin A. Compared with existing aflatoxin degrading bacteria, the strain CW574 can achieve excellent degrading effects under the condition of low-concentration toxin pollution. Under the condition of liquid fermentation, in a fermentation culture solution containing alflatoxin B1 and ochratoxin A with the final concentration being 20 micrograms per liter, the degrading rate of the strain CW574 on ochratoxin A is 90.1% in 48 h; the degrading rate of the strain CW574 on alflatoxin B1 is 85.5% in 48 h. When the strain CW574 is used for treating fodder (the final concentration is 20 micrograms per kg) polluted by toxins, the degrading rate on OTA is 48.3% in 48 h, and the degrading rate on AFB1 is 52.1% in 48 h. The strain CW574 has substantive application value and significance on the application aspects of food and feed biological detoxification.

The invention provided an enzyme linked immunosorbent assay kit used for detecting ochratoxin A. The enzyme linked immunosorbent assay kit comprises an elisa plate containing ochratoxin A coupling antigen, a standard solution of ochratoxin A, a concentrated enzyme conjugate, an enzyme conjugate working solution, a substrate color development solution, and a stopping solution. The invention also discloses a method used for detecting ochratoxin A using the enzyme linked immunosorbent assay kit, and comprises steps of pretreatment of samples, detection via the enzyme linked immunosorbent assay kit, and analysis of detection results. The enzyme linked immunosorbent assay kit can be used for detecting ochratoxin A residual quantity in forage (raw materials, auxiliary materials and concentrates); operation is simple and convenient; cost is low; sensitivity is high; and the enzyme linked immunosorbent assay kit is capable of realizing on-site monitoring, and is suitable for screening of a large amount of samples.

The invention discloses a biosensor for detecting zearalenone and ochratoxin A and a preparation method thereof, and a method for detecting zearalenone and ochratoxin A, and belongs to the technical field of harmful substance detection. The biosensor for detecting zearalenone is formed by self-assembling a ZEN aptamer which is a nucleic acid aptamer capable of specifically recognizing zearalenone and labeled by a fluorescent group at the 5' end and graphene oxide. The biosensor can detect ZEN and OTA at the same time, overcomes the problems that the scheme of a single detection method is tedious, the operation steps are complex, the detection cost is high and the required time is long. The two types of fungaltoxins are detected at the same time and are not mutually interfered, and the accuracy is high.