56results about How to "Play the role of signal amplification" patented technology

A method adopted by an electrochemical biosensor based on sulfonic functionalized grapheme-chitosan to detect methyl parathion belongs to the technical field of electrochemical sensors and is used for detecting methyl parathion residual quantity in vegetables, fruits and products thereof. The basis of the invention is that methyl parathion can play an inhibition role on acetylcholinesterase, and the acetylcholinesterase can catalyze acetylthiocholine chloride to achieve electrochemical reaction of hydrosulfuryl acetylcholine. Sulfonic functionalized grapheme-chitosan is decorated on the surface of a bare glass carbon electrode, so that not only acetylcholinesterase is effectively fixed on the electrode, but also an electrochemical signal is amplified; and the methyl parathion residual quantity is related with electrochemical summit current, so that a standard curve for quantified detection of methyl parathion is built. The invention aims to provide the methyl parathion quantified detection method with high sensitivity and strong operability and develops the application of novel material graphene.

The invention discloses an electrochemical sensor for detecting isocarbophos and acetamiprid at same time and a method system of the electrochemical sensor; the electrochemical sensor comprises an electrode, a beacon probe layer, a 6-mercaptohexan-1-ol (MCH) closure layer, and a homogenous reaction product layer sequentially from inside to outside; the beacon probe layer is modified with methylene blue and ferrocene having electrochemical signals not mutually affected; a preparation method comprises: polishing the electrode, treating with H2SO4 and H2O2, and modifying the surface of the electrode with a beacon probe. The electrochemical sensor according to the invention is simple to prepare and has good performance stability, the electrode is highly repeatable, and the electrochemical sensor is applicable to the detection of isocarbophos and acetamiprid in terms of food safety and the actual application of biosensor industrialization; the electrochemical sensor can provide quick online detection for isocarbophos and acetamiprid in food, and isocarbophos and acetamiprid detection limits are 0.12 ppb and 0.37 ppb respectively.

The invention discloses a zearalenone-vomitoxin double-channel immune quantitative test strip, and belongs to the technical field of immunoassay and rapid detection. A fluorescent probe is prepared bymarking fluorescent microspheres; a fluorescent microsphere-zearalenone monoclonal antibody, a fluorescent microsphere-vomitoxin monoclonal antibody and a fluorescent microsphere-goat anti-rabbit secondary antibody are included, and zearalenone artificial antigen, fluorescent microsphere artificial antigen and goat anti-mouse secondary antibody are sprayed on a nitrocellulose membrane to serve asa detection line T1, a detection line T2 and a quality control line C respectively to prepare the immunochromatographic test strip; and zearalenone and vomitoxin in the sample are analzyed simultaneously and quantitatively by reading the fluorescence value of the detection lines in a fluorescence immunoassay analyzer by means of a competitive immunoassay method. The method overcomes the defect that colloidal gold is not easy to store in the test strip technology, and the method for preparing the fluorescent probe is simple, efficient and high in sensitivity.

The invention provides a biosensor for detecting streptomycin based on an aptamer. The biosensor comprises a gold electrode, wherein an MB capture probe layer, HAP and an ssDNA layer are sequentially modified on the gold electrode. The invention also provides a preparation method of the biosensor. Based on specific recognition of the aptamer and the target, the sensor has the advantages of high detection speed, low detection limit, high specificity and the like, the defects of the conventional streptomycin detection method can be overcome, and rapid and accurate quantitative determination is realized.

The invention relates to an aptamer based salmonella typhimurium detection biosensor and a preparation method thereof. Signal amplification is realized by continuous generation and cyclic utilization of Primer, and consequently high-sensitivity detection of salmonella typhimurium is realized, and lower detection limit can be acquired. The aptamer based salmonella typhimurium detection biosensor is high in specificity and sensitivity, low in cost and quick in detection. By the detection method, a salmonella typhimurium detection limit is 5-15cfu/mL, and a detection range is 1*10-1*107cfu/mL.

The invention discloses a method for amplifying antibody marking signal or nucleic acid probe marking signal, and the main scheme is that: lipopolysaccharide of gram negative bacteria and an antibody are crosslinked, or fungi (1,3)-beta-D-glucan of fungi cell wall and the antibody or a nucleic acid probe are crosslinked, and then tachypleus amebocyte lysate and the gram negative bacteria lipopolysaccharide or fungi cell wall (1,3)-beta-D-glucan which is crosslinked with the antibody are specifically reacted, thereby improving the sensitivity of the antibody or nucleic acid probe detection. The system for amplifying antibody marking signal or nucleic acid probe marking signal can detect object substrates lower than pg level content.

The invention provides a fluorescent biosensor based on nucleic acid recognition induction and an application thereof. The fluorescent biosensor is composed of gold nanoparticles, a recognition sequence and n signal probes, the recognition sequence is single-stranded DNA, the surfaces of the gold nanoparticles are connected with one ends of a plurality of recognition sequences; the signal probe issingle-stranded DNA of which one end is connected with a fluorophore; and the fluorophores of the signal probes are different. The single-stranded DNA sequence of the signal probe is composed of a first DNA sequence and a second DNA sequence. The fluorophore is connected with a second DNA sequence; each recognition sequence connected with the gold nanoparticles is hybridized with the first DNA sequence of the n signal probes; the recognition sequence is complementary with the miRNA-155, and after the recognition sequence is hybridized with the miRNA-155, the 3'end of the recognition sequenceis changed into a blunt end which can be recognized and hydrolyzed by the exonuclease III, and the n signal probes are all unlinked with the recognition sequence; wherein n is a natural number greaterthan 1.

The invention discloses a preparation method of a trichinella spiralis antigen labeled gold nanorod. The method comprises the following steps: preparing spherical gold nanoparticle seeds by reducing an HAuCl4 solution with a reducing agent; adding the spherical gold nanoparticle seeds into a growth medium, and enabling the spherical gold nanoparticle seeds to grow into a rod-shaped gold nanorod ina rod micelle solution; labeling the gold nanorod by using an antigen excreted by trichinella spiralis larvae, thereby obtaining the trichinella spiralis antigen labeled gold nanorod. The invention further provides a trichinella spiralis antigen labeled gold nanorod prepared by the method. The gold nanorod is synthesized by selecting a 'seed mediated growth method', and the length-width ratio hasobvious advantages compared with a spherical nanorod; a gold nanorod labeling technology can be applied to serological test of trichinella spiralis, the detection kit is high in detected antibody dilution, early in time and low in infection gradient compared with a mouse serum antibody ELISA (Enzyme-linked Immuno Sorbent Assay) detection kit, and a novel technology can be provided for detecting early trichinosis infection and low infection gradient.

The invention discloses an electrochemical luminescence biosensor for detecting drug resistance of bacteria and a preparation method of the electrochemical luminescence biosensor. The preparation method comprises the following steps of: preparing an NH2-MIL-53 (Al) nanosheet; preparing a probe solution for detecting the drug resistance of the bacteria; and assembling the electrochemical luminescence biosensor for detecting the drug resistance of the bacteria. The electrochemical luminescence biosensor provided by the invention can rapidly, simply, reliably and effectively detect drug resistance. An electrochemical luminescence technology is used as a signal output mode; the technology has extremely high sensitivity; and the electrochemical luminescence biosensor detects whether the bacteria have drug resistance or not and can be used for quantitatively detecting the concentration of escherichia coli.

The invention provides a method for detecting salmonella typhimurium. The method comprises the following steps: preparing an arch-shaped probe from aptamer and primer; then adding target bacteria into a reacted homogeneous solution, performing incubation at 37 DEG C for 2 hours, combining a target with the aptamer, releasing a primer sequence, opening HP, combining the HP onto a helper, and completing a subsequent EXPAR process, thus generating amplification of a signal; then adding heme, hydrogen peroxide and ABTS, and detecting ultraviolet absorption at 410 nm through a spectrometer. The detection method provided by the invention has the advantages of high detection speed, low detection limit, high specificity and the like.

The present invention provides an electrochemical sensor for detecting mercury ions. According to the present invention, capture probe is fixed on the surface of an electrode through a Au-S bond, the surface of the electrode is modified with a reacted homogeneous phase solution, the RCA product in the homogeneous phase and the capture probe on the surface of the electrode are subjected to a hybridization reaction by incubating for 2 h at a temperature of 37 DEG C so as to fix the RCA product on the surface of the electrode, the obtained electrode is soaked for 10 min in a methylene blue solution, and the redox peak of MB is detected with a three-electrode working system. According to the present invention, the signal amplification is achieved through the target cycle amplification and the rolling ring amplification, such that the high-sensitivity mercury ion detection can be achieved, and the low detection lower limit can be obtained.

The invention provides an electrochemical electrode for detecting copper ions and a preparation method and application thereof. In an electrode modified material, SnO2 can be used as an active material, and RGO and a RGO / activated carbon mixture are used as active additives, and can improve the selectivity of the electrode. Carbon black and carbon nanotubes are used as conductive additives, and can play the role of signal amplification due to the high conductivity, a more obvious response current can be obtained in the detection of trace copper ions by use of the electrode, and the detection accuracy of the electrode is improved. The electrochemical electrode has the following advantages: simple preparation method, high sensitivity, good linear relationship between the current response strength and copper ion concentration, low ion detection limit, and wide application prospect.

The invention relates to a tactile sensor. The tactile sensor comprises a flexible substrate (4), a micro-nano optical fiber embedded in the flexible substrate (4) and a fingerprint-like structure patch attached to the surface of the flexible substrate (4), wherein the refractive index of the flexible substrate (4) is lower than that of the micro-nano optical fiber, and the hardness of the fingerprint-like structure patch is higher than that of the flexible substrate (4). According to the scheme, the shearing force can be rapidly detected.

The invention discloses a microcystis toxin immune quantification test strip based on fluorescent microsphere mark and belongs to the technical field of immune analysis and quick detection. Accordingto the test strip, a fluorescent probe is prepared by marking fluorescent microspheres; the test strip is prepared from fluorescent microsphere-microcystis toxin artificial antigen and fluorescent microsphere-goat anti rabbit second antibody. The goat anti rabbit second antibody and rabbit IgG antibody are respectively sprayed on nitrocellulose membranes to serve as a detection line and a qualitycontrol line to prepare an immunochromatography test strip; competition immune method is utilized to quantitatively analyze microcystis toxin in a sample by reading a fluorescent value of the detection line on a fluorescence immunity analyzer. The method not only overcomes the defect that colloidal gold in a test strip technology is not easy to store; furthermore, a fluorescent probe preparation method has the advantages of simpleness and high efficiency.

The invention belongs to the field of electrochemical detection, and particularly provides a construction method of a photoelectrochemical sensor for non-labeling detection of 4-chlorophenol. The construction method comprises the following steps that step 1, graphite-phase carbon nitride (GCN) is prepared; step 2, an Ag/GCN/carbon sphere (Ag/GCN/C) ternary photoelectric active material is prepared; step 3, the photoelectrochemical sensor for the non-labeling detection of 4-chlorophenol is constructed. Compared with a traditional detection method, a photoelectrochemical detection method of 4-chlorophenol has the advantages that the operation is simpler, more convenient and more flexible, instrument and equipment are simpler, the reagent dose is less, and the detection cost is low.

The invention discloses a molecularly imprinted polymer test strip used for detecting 17 beta-Estradiolum and a preparing method thereof. The test strip is modified with the molecularly imprinted polymer, and the molecularly imprinted polymer bears specific binding sites of 17 beta-Estradiolum. The specific binding sites can not only carry out specific binding with enzyme marked 17 beta-Estradiolum, but also can carry out specific binding with 17 beta-Estradiolum. The detection is realized through the competitive binding between the 17 beta-Estradiolum to be detected, the enzyme marked 17 beta-Estradiolum and the biding sites. The molecularly imprinted polymer test strip used for detecting 17 beta-Estradiolum can realize the specific binding of the target template module and can magnify signal through the color reaction between enzyme and substrate. The method for detecting 17 beta-Estradiolum does not need complicated sample pretreatment, has simple operation, low cost, and good reliability, and can be used for the detection of 17 beta-Estradiolum in food or clinic.

The invention provides a preparation method of a jettisonable aptamer sensor for OTA (ochratoxin) sensitivity detection. The method includes the steps of: S1. preparation of an MPA modified nano colloidal gold solution; S2. activation of an aptamer; S3. preparation of a PDDA modified screen-printed electrode; S4. preparation of a gold nanoparticle modified screen-printed electrode; and S5. preparation of aptamer modified Au NPs-SPCE. Compared with the traditional detection method, the label-free impedance detection method of OTA proposed in the invention has the advantages of simpler and more flexible operation, simpler instrument and equipment, small reagent dosage, and low detection cost, etc.

The invention relates to a pressure transducer having stressing concentration. The pressure transducer includes a housing which assumes a cylindrical structure having two ends blocked and is provided with a mounting hole and an air exhaust hole thereon; a metal membrane which is arranged inside the mounting hole and has an circumferential edge which is fixedly connected to the inner wall of the mounting hole, the metal membrane being provided with a stress concentration groove thereon; and a FBG fiber which is fixed to the outside of the metal membrane. According to the invention, the pressure transducer adopts the metal membrane and the housing to enclose a cavity, and the metal membrane is provided with the stress concentration groove, such that a signal can be amplified and the sensitivity of the pressure sensor is higher.

The invention discloses an aptamer-based histamine electrochemical sensor, a preparation method thereof, and application of the same in river crab detection. The aptamer-based histamine electrochemical sensor is prepared by the following steps of: firstly, modifying flower-shaped nanogold on the surface of conductive glass based on an electro-deposition method, meanwhile, connecting a sulfhydrylation modified histamine aptamer on the surface of AuNFs/ITO based on an Au-S bonding effect, constructing a histamine electrochemical sensing interface; preparing bismuth vanadate nano flower balls through hydro-thermal synthesis; and on the basis of a sodium borohydride reduction method, introducing gold nanoparticles to the surfaces of the bismuth vanadate nano flower balls, and self-assembling ligand DNA matched with the histamine aptamer to obtain an electrochemical probe DNA/Au-coated BiVO4, namely the aptamer-based histamine electrochemical sensor.

The invention relates to a pressure sensor, a pressure sensing array and a preparation method thereof. The pressure sensor comprises a thin film transistor, the thin film transistor comprises a substrate, a bottom gate electrode, an insulating layer, a source electrode, a drain electrode, a semiconductor layer, a passivation layer and a top gate electrode, and the top gate electrode and the drain electrode are electrically connected through an interconnection structure penetrating through the passivation layer; a resistive pressure sensitive film which is located above the top gate electrode and the passivation layer, and a gap is formed between the resistive pressure sensitive film and the top gate electrode; and a top electrode which is located on the surface, deviating from the top gate electrode, of the resistive pressure sensitive film. According to the invention, the resistive pressure sensitive thin film and the thin film transistor are longitudinally integrated, so that the area of the pressure sensor is reduced, and a high-resolution sensor array is easy to prepare.