514 results about "Streptavidin" patented technology

The invention provides a nucleic acid aptamer for specific recognition of morphine and application of the nucleic acid aptamer, and belongs to the technical field of biosensing and detection. The nucleotide sequence of the nucleic acid aptamer is as shown in SEQ ID NO: 1. The screening method is based on a Capture-SELEX technology and comprises the key steps that streptavidin magnetic beads are used for fixing an ssDNA library, estradiol, deabietic acid and totarol are introduced to serve as reverse screening substances so as to remove non-specific sequences, and finally the high-specificity aptamer is obtained through high-throughput sequencing and affinity determination. The dissociation constant of the aptamer and morphine is 127.31 nM, and the aptamer shows high affinity and high specificity. The invention further relates to application of the aptamer in preparation of a sensor and a kit for detecting morphine, and a new technical means is provided for rapid detection of morphine.

The invention relates to a method for improving chemiluminescence immunoassay sensitivity of magnetic particles, a detection kit and application thereof, firstly, magnetic beads are coupled with an antibody, then magnetic beads are sealed to obtain a magnetic bead coated antibody, sealing comprises pre-sealing and second-step sealing, glycine and ethanolamine are added in the pre-sealing process, and in the second-step sealing process, glycine and ethanolamine are added in the second-step sealing process. Casein hydrolysate and dodecyl dimethyl amine ethyl lactone are added; then coupling the antibody with alkaline phosphatase or streptavidin to obtain an alkaline phosphatase labeled antibody or a streptavidin labeled antibody; the magnetic bead coated antibody, the alkaline phosphatase labeled antibody or the streptavidin labeled antibody is used for sample detection. The method is high in sensitivity and wide in detection range, is adaptive to a common immunoassay instrument, does not need expensive equipment, and is also simple to operate; in addition, the AMH concentration with extremely low concentration can be accurately detected.

The invention discloses a high-sensitivity cardiac troponin-T electrochemiluminescence detection kit. The kit comprises a magnetic microsphere reagent coated by a high-sensitivity cardiac troponin-T capture antibody and a high-sensitivity cardiac troponin-T detection antibody reagent labeled by an electrically neutral ruthenium compound, the structural general formula of the electrically neutral ruthenium compound is # imgabs0 # n = 0-9; the magnetic microsphere reagent coated with the high-sensitivity cardiac troponin-T capture antibody comprises a magnetic microsphere coated with the high-sensitivity cardiac troponin-T capture antibody and a diluent; the electrically neutral ruthenium compound labeled high-sensitivity cardiac troponin-T detection antibody reagent comprises an electrically neutral ruthenium compound labeled high-sensitivity cardiac troponin-T detection antibody and a diluent; the diluent is prepared from piperazine-1, 4-diethyl sulfonic acid or 3-(N-morpholinyl)-2-hydroxy propanesulfonic acid. When the high-sensitivity cardiac troponin-T electrochemiluminescence detection kit is used for detection, a reaction system does not contain streptavidin coated magnetic beads or biotinylated antibodies, so that interference of biotin in a sample is avoided.

The invention provides an immunodetection method of a multi-index immune checkpoint detection kit, which belongs to the technical field of immunodetection and comprises three main stages of sample preparation, immune reaction and data analysis. The method comprises the following steps: firstly, carrying out centrifugal separation to obtain a plasma sample, and preparing a fluorescent microsphere coupled capture antibody and biotin labeled detection antibody compound; then carrying out immune reaction, forming a sandwich type immune complex through specific binding, and adding streptavidin marked by phycoerythrin for signal amplification. Detecting a fluorescence signal by adopting a flow cytometer to obtain an original data matrix; a contribution feature vector, a utility feature vector and an expression feature matrix are extracted through a feature decomposition algorithm, and a deep learning model of a total-score-total structure is established for data analysis. Finally, a detection report containing a quantitative result, an importance score and reliability evaluation is generated, and the technical problem that in the prior art, the analysis accuracy of a multi-index immune checkpoint detection result is insufficient is solved.

The invention belongs to the field of immunological detection, and provides a double-antibody sandwich ELISA kit for detecting the content of human beta-NGF. The enzyme-linked immunosorbent assay kit constructed by the invention is based on a double-antibody sandwich method, and is combined with a biotin-streptavidin signal amplification system and an enzyme developing amplification system, so that the detection sensitivity and specificity are greatly improved, and low-content samples can be accurately and quickly detected. The kit shows excellent stability and specificity and can be used for quantitatively detecting the content of beta-NGF in samples such as human serum, cell supernatant or tissue homogenate, so that an objective detection basis is provided for diagnosis, curative effect evaluation and pathogenesis research of related diseases.

The invention discloses a method for screening a non-natural nucleic acid aptamer of targeted thrombin based on streptavidin magnetic beads and application, and belongs to the technical field of biology. According to the method, an initial screening library is efficiently constructed through a primer extension technology, and a chemical modification SELEX technical process is simplified; a streptavidin magnetic bead separation technology is introduced, so that the screening specificity and efficiency are improved, the screening period is remarkably shortened, and the cost is reduced; by selecting non-natural nucleic acid modification sites and adopting a strategy of combining reverse screening and forward screening, high specificity and affinity of the aptamer are ensured, and limitation of an existing screening method is overcome; the screened non-natural nucleic acid aptamer shows high affinity and excellent stability, the aptamer with a specific structure and function is successfully obtained by optimizing the proportion of nucleoside triphosphate monomers and extension reaction conditions, and a wide application prospect is provided for the fields of drug development, biosensor preparation and the like. A new path is opened up for research and application of the nucleic acid aptamer.

The invention discloses a preparation method of Fe3O4 magnetic nanoparticles rich in carboxyl groups on the surface, which comprises the following steps: modifying Fe3O4 nanoparticles by using polyethylene glycol and silicon dioxide to enhance the dispersity and biocompatibility of the magnetic nanoparticles, modifying the surfaces of PEG-Fe3O4 coated SiO2 nanoparticles by using a silane coupling agent containing silane groups and unsaturated double bonds to obtain the magnetic nanoparticles rich in carboxyl groups on the surface, and modifying the magnetic nanoparticles rich in carboxyl groups on the surface by using a silane coupling agent containing silane groups and unsaturated double bonds to obtain the magnetic nanoparticles rich in carboxyl groups on the surface. Then octavinyl-POSS and double bonds on the surfaces of the nano particles are subjected to click modification to form an octahedral cage, 4-mercaptobenzoic acid and double bonds are further subjected to click modification, the surfaces of the nano particles are rich in carboxyl, and a polymer brush rich in carboxyl is constructed. Compared with a conventional streptavidin coupling method, a high-density polymer chain provides a large number of carboxyl active binding sites, so that the streptavidin coupling amount is increased, the antibody coupling rate is increased, and a solution is provided for applications such as high-sensitivity biological detection, efficient targeted drug delivery and stable immunoassay.

The invention relates to a second antibody for resisting mouse IgG and rabbit IgG as well as a preparation method and application of the second antibody. The second antibody of the anti-mouse IgG and the rabbit IgG sequentially comprises an anti-mouse IgG nano antibody, a biotin fixed-point binding peptide fragment and an anti-rabbit IgG nano antibody from an amino terminal to a carboxyl terminal. According to the design of the second antibody of the anti-mouse IgG and rabbit IgG with a brand-new structure and the preparation method, high-efficiency expression is realized, the second antibody of the anti-mouse IgG and rabbit IgG capable of realizing fixed-point biotinylation is obtained, the second antibody can be further subjected to various modification reformation based on a biotin-streptavidin bridge, the preparation method of the second antibody of the polymerase labeled anti-mouse IgG and rabbit IgG is further developed, and the application of the second antibody of the polymerase labeled anti-mouse IgG and rabbit IgG is expanded. According to the method, the polymerase-labeled mouse-rabbit universal secondary antibody with similar affinity to mouse IgG and rabbit IgG is obtained, the preparation period of the secondary antibody can be shortened, the preparation process of the secondary antibody is simplified, the stability between batches is improved, and meanwhile, the dependence on experimental animals is reduced.

The invention discloses a chemiluminescence heparin binding protein kit and a determination method thereof. The kit comprises reagent components of a reagent R1, a reagent R2 and a reagent R3, as well as a matched calibrator, a matched quality control product, a matched pre-excitation liquid, a matched excitation liquid and a matched cleaning liquid, wherein the reagent R1 contains magnetic particles coated with streptavidin, and the reagent R2 and the reagent R3 are respectively monoclonal antibodies which are labeled by acridinium ester and biotin and are used for recognizing different epitopes of human HBP. The kit shows better sensitivity, wider detection range and high specificity, and can effectively reduce potential endogenous and exogenous interference in clinical samples of potential interference people.

The present invention discloses a hs-TnI detection method based on quantum dot microspheres, which directly reacts a sample with a first solution containing antibody 1 and a second solution containing antibody 2 to generate a sandwich structure complex of antibody 1-antigen-antibody 2, and the antigen and antibody react in a reaction cup, incubate at a constant temperature, and the reaction time is longer, and the reaction is more sufficient, which is conducive to the improvement of detection sensitivity. At the same time, during chromatography, with the high affinity of streptavidin and biotin, the complex obtained by the reaction can be better captured on the T line, so that the reaction can be made more sensitive, and the detection time is also faster relative to the existing reagent strips. Further, combined with the advantages of high sensitivity and wide linear range of quantum dot microspheres, detection repeatability (CV) is better, CV is increased from the traditional 15wt% to within 8wt%, and the detection sensitivity is as high as 2pg / ml, while the linear range is 2-30000pg / ml, and full coverage is achieved for low-concentration and high-concentration samples.

The invention relates to a kit for detecting granzyme B as well as a preparation method and application of the kit. The kit for detecting granzyme B comprises a magnetic microsphere working solution, a detection antibody and streptavidin labeled phycoerythrin. The invention also provides a preparation method of the kit for detecting granzyme B. The preparation method comprises the following steps: coupling a granzyme B antibody by using a magnetic fluorescence coding microsphere to obtain a granzyme B antibody-coupled magnetic fluorescence coding microsphere; labeling the granzyme B detection antibody with biotin to obtain a detection antibody; the preparation method comprises the following steps: mixing granzyme B antibody coupled magnetic fluorescence coded microspheres, a PBS buffer solution, a stabilizer, a preservative, a surfactant and a blocking agent to obtain a magnetic microsphere working solution, and assembling the magnetic microsphere working solution with a detection antibody and streptavidin labeled phycoerythrin to obtain the kit. The invention also provides a kit for detecting serum granzyme B. The invention solves the problem of poor detection reliability caused by false positive results and cross reaction in the existing serum granzyme B detection method.

The present invention belongs to the technical field of immunochromatography. Provided are a streptavidin multimer, and a preparation method therefor and the use thereof. The prepared streptavidin multimer has a strong affinity for a biotin / fluorescein nucleic acid probe. A nucleic acid test strip prepared with the prepared streptavidin multimer can realize rapid and high-sensitivity detection of a sample to be detected. Results can be obtained in 5 minutes, the false positive rate can be reduced, and the cost of the nucleic acid probe is reduced, which is convenient for non-professional technicians to easily and accurately judge the results.

The present disclosure relates to a method for increasing the sensitivity of latex immunoturbidimetry reagents. A biotin-streptavidin amplification system, a biotin-labeled antibody and streptavidin cross-linked latex microsphere are used, and the kit is characterized by comprising a first reagent and a second reagent, the first reagent comprises a buffer solution, a stabilizer, a polymerization accelerator, a preservative, a blocking agent and the biotin-labeled antibody, and the second reagent comprises a buffer solution, a stabilizer, a polymerization accelerator, a preservative, a blocking agent and a streptavidin cross-linked latex microsphere. The second reagent comprises a buffer solution, a stabilizer, latex microspheres labeled by streptavidin and a preservative. According to the present invention, the antibody is placed in the first reagent, such that the contact time of the antibody and the antigen is increased, the recognition efficiency is improved so as to improve the reaction sensitivity, and after the second reagent is added, the biotin-labeled antibody and the streptavidin latex microspheres are rapidly combined to form the agglutination so as to produce different reaction gradients, such that the sensitivity and the repeatability are significantly improved.

The invention provides an anti-streptavidin antibody which is high in specificity, high in sensitivity, less in cross reaction and small in batch difference. The antibody not only can realize similar application of a streptavidin-biotin system, but also can be used in combination with the streptavidin-biotin system for related applications such as cell sorting, immunochromatography and the like.

The invention belongs to the technical field of food microorganism detection, and provides a lateral flow chromatography kit for high-sensitivity quantitative detection of salmonella enteritidis, which comprises a salmonella enteritidis RPA primer group and a lateral flow chromatography test strip, raman label streptavidin, a Digoxin antibody and a streptavidin antibody are coated on the lateral flow chromatography test strip. The reporter probe is combined on the release pad of the flow measurement chromatography test strip, has two characteristics of colorimetry and SERS (Surface Enhanced Raman Scattering), can finish simultaneous qualitative and quantitative detection of pathogenic bacteria, and improves the detection sensitivity; and the Digoxin antibody and the streptavidin antibody are respectively combined on the detection line and the quality control line. The kit does not need to use large experimental equipment in the whole detection process, is high in detection accuracy and good in specificity, and is very suitable for real-time detection under the condition of relatively low development level.

The invention discloses a method for detecting 17 beta-estradiol by using a colorimetric-fluorescent dual-mode biosensor, and belongs to the technical field of chemical analysis and detection. According to the method, a colorimetric-fluorescent dual-mode biosensor for detecting 17 beta-estradiol is established based on oxidase-like activity and fluorescence quenching characteristics of manganese dioxide nanosheets and catalytic characteristics of alkaline phosphatase by taking a nucleic acid aptamer as a recognition molecule. The synthesis cost of the nucleic acid aptamer is low, the method has universality, and other target objects can be detected by changing the nucleic acid aptamer; mBs-DNA-ALP is prepared by using a biotin-streptavidin reaction and a DNA hybridization reaction, and a structure conversion process from double-stranded DNA to an aptamer / target compound is realized by using targeted induction, so that a detection signal is amplified; according to the method for detecting 17 beta-estradiol through colorimetric-fluorescence signals, dual-mode output is achieved, results are verified and supplemented mutually, and the specificity and accuracy of the method are improved.

The invention provides a preparation method of streptavidin magnetic beads, and relates to the technical field of preparation of polymer composites.The preparation method comprises the steps that S1, PS / SiO2 composite microspheres are prepared; s2, carboxyl magnetic beads are prepared on the basis of the PS / SiO2 composite microspheres prepared in the step S1; s3, activating the carboxyl magnetic beads; s4, carrying out covalent coupling on the carboxyl magnetic beads and streptavidin; step S5, stripping of the physically combined streptavidin; and S6, sealing and storing the streptavidin magnetic beads. The streptavidin magnetic beads prepared through the method are controllable in particle size, superparamagnetic, good in stability and high in activity, compared with a traditional method, a cross-linking agent does not need to be additionally added, the process is effectively simplified, the cost is reduced, the streptavidin magnetic beads have excellent performance in the using process of a chemiluminescence platform, and the process is easy to amplify and beneficial to control.

The application provides a preparation method of a functionalized phage probe and application of the functionalized phage probe in detection of escherichia coli. The functionalized phage is a recombinant phage (M13KO7@SaBP) in which streptavidin binding peptide (SaBP) is fused and expressed at the N terminal of the main capsid protein P8 protein of M13K07 phage. In the application, the gene encoding SaBP (MDVEAWLGAR) is inserted into the N terminal of the P8 protein gene of M13K07 phage by site-directed mutagenesis to prepare M13K07@SaBP. The stable signal amplification is realized by using the abundant P8 protein (about 2700) of M13 phage and the super strong binding force of biotin-streptavidin, the interference of food sample matrix is reduced by combining the magnetic separation technology, and a detection method of escherichia coli with high sensitivity and small sample matrix interference is constructed.

The invention relates to a multi-target gene detection method based on a liquid phase chip, which comprises the following steps: S1, target genes: selecting O-type serum antigens to synthesize key genes; s2, probe design: synthesizing key genes aiming at seven serotype antigens, and designing a specific primer pair; s3, Luminex microsphere coding and coupling: using MagPlex microspheres with different fluorescence codes, and fixing a probe on the surface of the microspheres through a carboxyl-amino coupling method; s4, carrying out multiplex PCR amplification and hybridization detection; s5, a data analysis algorithm is adopted, and a threshold value is set, wherein a negative control MFI mean value + 3 * standard deviation is a Cuff value; and positive judgment: the MFI value of the microsphere corresponding to a certain serotype is greater than or equal to Cuff, and the signal-to-noise ratio (S / N) is greater than or equal to 5. By adopting the technical scheme, the method is based on a Luminex liquid phase chip technology, target gene sequences are amplified through multiple PCR (Polymerase Chain Reaction), and high-flux specific detection on seven serotypes of Escherichia coli is realized by combining microsphere coding probe hybridization and a biotin-streptavidin signal amplification system.

The invention belongs to the technical field of biology, and particularly discloses a pH response type probiotic-liposome hybrid system, a preparation method and application thereof, and the pH response type probiotic-liposome hybrid system comprises engineered escherichia coli Nissle 1917, pinocembrin-loaded biotinylated liposome and an enteric polymer; wherein the engineered escherichia coli Nissle 1917 is in non-covalent binding with the biotinylated liposome loaded with the pinocembrin through surface display streptavidin, so that EcNPIN is formed, and the EcNPIN is coated with an enteric polymer, so that the pH response type probiotic-liposome hybrid system is formed. The pH response type probiotic-liposome hybrid system EcNPIN-L provided by the invention can resist the acidic environment of the stomach, completes pH response release and colonization in the intestinal tract, solves the problems of lack of intestinal tract localization of drugs and low probiotic treatment efficiency, improves the local intestinal tract concentration of pinocembrin, and promotes intestinal tract colonization of probiotics.

A method and kit are provided for detecting anti-drug antibodies (ADAs) against self-assembling trimeric biologics, such as XPro1595, a pegylated variant of soluble human Tumor Necrosis Factor, in biological samples, particularly human serum. The method employs an Affinity Capture Elution-Protein A / G (ACE-AG) assay that overcomes non-specific reagent interactions inherent in conventional bridging and standard ACE assays due to the biologic's dynamic monomer exchange. The assay utilizes a two-plate system: a streptavidin-coated plate with biotinylated trimeric biologic captures ADAs, which are eluted, neutralized, and transferred to a protein A / G-coated plate for specific immunoglobulin capture and detection with a sulfo-tagged trimeric biologic via electrochemiluminescence. The kit includes pre-coated plates, labeled biologics, elution and neutralization solutions, assay buffer, confirmatory reagent, and instructions. The assay offers a robust, specific, and sensitive solution for immunogenicity testing of trimeric biologics.

The invention discloses a ctEVs separation and analysis method with time resolution capability and application thereof. The ctEVs separation and analysis method comprises the following steps: S1, culturing cells by adopting glycometabolism markers; or injecting the animal by adopting a glycometabolism marker; step S2, manufacturing a fishbone-shaped micro-fluidic chip modified by streptavidin; s3, separating and analyzing the new tumor source extracellular vesicles by the micro-fluidic chip, and co-incubating the extracellular vesicles and the aptamer probe co-modified by Biotin and DBCO to realize biotinylation of the new tumor source extracellular vesicles; the aptamer probe is a heterologous multivalent aptamer probe; step S4, capturing biotin-labeled target extracellular vesicles by adopting a chip; and S5, acquiring a chip image by using a fluorescence microscope, and analyzing the concentration of the target extracellular vesicles in the sample according to a fluorescence signal. The method can be used for screening tumor circadian rhythm markers and the like.

The present invention relates to a monoclonal antibody capable of binding to biotin. In one embodiment the monoclonal antibody according to the invention also does not bind to a biotin moiety on a biotinylated molecule, wherein the biotin moiety is attached to the molecule via the carbon atom of the carboxyl function of the valeric acid moiety of biotin. Also disclosed is a method for generation of an antibody as disclosed herein. The monoclonal antibody according to the invention is of specific use in a method for measuring an analyte in a sample, wherein a (strept)avidin / biotin pair is used to bind a biotinylated analyte specific binding agent to a (strept)avidin coated solid phase.

A cell processing platform and method for selecting and isolating target cells, such as T-cells, NK-cells, or hematopoietic stem cells, from a biological sample using functionalized microbubbles. The platform employs microbubbles with lipid shells, functionalized with streptavidin and biotinylated linkers, to bind specific target cells and render them buoyant within the suspension. A centrifugation module separates non-target cells by sedimentation while maintaining the buoyancy of target cell-microbubble complexes. A pneumatic control system disrupts the microbubbles under controlled pressure or frequency, releasing the target cells for downstream processing without compromising viability. Additional features include a microbubble generation module capable of sequentially functionalizing ligands for multi-step cell selection and a temperature-controlled environment to ensure ligand stability. The system supports non-destructive cell release and sorting, enabling precise, contamination-free, and high-efficiency cell isolation for therapeutic and research applications.

A chimeric antigen receptor is disclosed that includes: (a) an extracellular high affinity streptavidin; (b) a hinge domain from CD8; (c) a CD28 transmembrane domain; (d) an intracellular 4-1BB and / or CD28 signaling domain; and (e) an intracellular CD3 zeta signaling domain, wherein (a)-(e) are in N-terminal to C-terminal order. Nucleic acids encoding this chimeric antigen receptor, and T and natural killer (NK) cells transformed with this chimeric antigen receptor are also disclosed. The use of this chimeric antigen receptor for the treatment of tumors is also disclosed.

The invention relates to a streptavidin polymer as well as a preparation method and application thereof, and belongs to the technical field of immunochromatography. The prepared streptavidin polymer has strong affinity with a biotin / fluorescein nucleic acid probe, nucleic acid test paper prepared from the prepared streptavidin polymer can realize rapid and high-sensitivity detection on a detected sample, a result can be obtained within 5 minutes, the false positive rate can be reduced, the cost of the nucleic acid probe is reduced, and the method is suitable for popularization and application. And non-professional technicians can conveniently, easily and accurately judge the result.

The invention provides an IL-13 detection kit based on a magnetic particle chemiluminescence method, and belongs to the technical field of medical detection.The kit comprises a reagent R1, a reagent R2, a reagent R3 and a reagent R4, the reagent R1 comprises a magnetic particle suspension, the reagent R2 comprises an analysis buffer solution, the reagent R3 comprises an IL-13 antibody solution, and the reagent R4 comprises a magnetic particle solution. The IL-13 antibody solution contains a biotin-labeled IL-13 antibody, the concentration of the biotin-labeled IL-13 antibody is 0.1-1.0 mg / mL, and the labeling ratio of the IL-13 antibody to biotin is 1: (5-50); and the reagent R4 comprises a streptavidin buffer solution. The kit is adaptive to a chemiluminescence instrument, can rapidly and effectively detect the concentration of IL-13, and improves the sensitivity, accuracy and detection efficiency of IL-13 detection. The invention further provides a preparation method and application of the IL-13 detection kit based on the magnetic particle chemiluminescence method.

The invention belongs to the technical field of biochemical detection, and particularly relates to a micro-fluidic chip PSMA prostate cancer circulating tumor cell immunoenrichment detection kit and a preparation method thereof. According to the kit, an EpCAM antibody, a Vimentin antibody and a double-site PSMA capture combination are fixed in a chip channel through a streptavidin-biotin system, double enrichment of epithelial and mesenchymal CTCs is achieved, PSMA targets are recognized through combination of an aptamer and the antibody, and the detection specificity and sensitivity are improved. Competitive oligopeptides are further introduced to block non-specific binding sites on the surfaces of leukocytes and reduce false positive. By combining a multiple fluorescent chromosome system and a double-antibody nucleic acid probe signal amplification strategy, accurate recognition and quantification of CTC and PSMA positive cells are realized. The scheme is suitable for early screening, curative effect evaluation and relapse monitoring of prostate cancer, and has a good clinical application prospect.

The invention provides a multicolor visual semi-quantitative detection method for miRNA in skin interstitial fluid, which comprises the following steps: extracting a skin interstitial fluid sample in a minimally invasive manner by combining a microneedle patch with a vacuum negative pressure technology; the method comprises the following steps: incubating a skin interstitial fluid sample and a magnetic nanoprobe of which the surface is immobilized with a hairpin probe H1, opening H1 in the presence of target miRNA, triggering a subsequent hybridization chain reaction of a hairpin probe H2 and H3, and constructing a biotin-rich DNA compound on the surface of a magnetic bead; the method comprises the following steps: carrying out enzyme labeling by using an alkaline phosphatase-streptavidin conjugate, catalyzing ascorbic acid phosphate to generate ascorbic acid to reduce potassium iodate, and generating an iodine elementary substance to etch a gold nano bipyramid, so that the color of a solution is changed, and high-sensitivity detection on target miRNA is realized. The multi-color visual detection method provided by the invention is combined with the gold nano bipyramid localized surface plasmon resonance property change, so that near-full spectrum color change can be generated, and the portability of the sensor and the accuracy of visual analysis can be improved.

The present invention provides an application of a highly homogeneous monovalent streptavidin tetramer in the field of detection. Specifically, the present invention provides a detection system, and the detection system includes: (a) a multi-component complex having a structure shown in Formula I, (A-B)-(C-D m ) n (Formula I) Each component in the formula includes: A is a second binding protein that can specifically bind to a target analyte; B is the biotin; C is a monovalent streptavidin tetramer; D is a fluorescent label; "-" is a bond or a linking group; and, m is a real number between 1 and 6, and n is a real number between 2 and 8; (b) a first binding protein crosslinked to a solid-phase carrier Z0, and the first binding protein can specifically bind to the target analyte; (c) an optional target analyte; the first binding protein and the second binding protein can respectively bind to the target analyte, and there is no competition between the two. The detection system provided by the present invention can improve the stability of the detection reagent and ensure the sensitivity and accuracy of the detection.