879 results about "Fluorescent microspheres" patented technology

The invention discloses a fluorescent microsphere immunity-chromatography test strip for detecting food-borne pathogenic microorganisms in a rapid, specific, qualitative and quantitative manner and a preparation method thereof. Filter paper, a sample pad, a glass fiber membrane spray-painted by fluorescent microsphere marked food-borne pathogenic microorganism monoclonal antibodies or polyclonal antibodies, a nitrocellulose membrane and drinking paper are stuck to an underplate orderly in a related joint manner; the food-borne pathogenic microorganism monoclonal antibodies or the polyclonal antibodies are coated on the nitrocellulose membrane and are used as a detection area; and anti-mouse antibodies are coated on the nitrocellulose membrane and used as a quality control area. The test strip has the preparation steps as follows: (1) samples to be detected are processed; (2) the nitrocellulose membrane is prepared; (3) a fluorescent microsphere pad is prepared; (4) the test strip is assembled; and during the detection process, the CCD scanning technique is utilized to collect all emission spectrums, and then the emission spectrums are analyzed through a fluorescence analyzer and relevant software after accumulation and multiplication, so that the quantitative detection is realized. The fluorescent microsphere immunity-chromatography test strip and the preparation method thereof are mainly used for qualitative and quantitative detection of all the food-borne pathogenic microorganisms in food safety inspection.

Fluorescent microspheres for the measurement of blood flow are provided. The microspheres are substantially uniform in diameter and have a hydrophobic surface, which allows them to circulate more freely throughout bloodstream, while reducing immunogenicity, particle aggregation and bioaccumulation. The hydrophobic surface on each microsphere is generally comprised of polymeric material having a limited surface charge.

The invention discloses a method for preparing fluorescent microspheres immunochromatographic test paper strip and quantitative detection method. The invention takes the luminous nano-particles of dual-structure silicon dioxide compound organic dye as a marker, uses the immunochromatographic technology for preparing fluorescent microspheres immunochromatographic test paper strip, and then prepares a detection card which consists of a sample pad, a glass fiber membrane, a nitrocellulose membrane and absorbent paper, wherein the nitrocellulose membrane is fixedly provided with a detection line and a quality control line. In the detection process, the best excitation light souce of fluorescent microspheres is used for excitation; after the emitted fluorescence passes through a filter, a CCD scanning technology or fiber-optic technology is used for collecting, accumulating or multiplicating the emitted spectra which is then converted into a numerical signal; then the measured fluorescence intensity of the detection line is multiplied by a correction coefficient, and later the corrected fluorescence intensity is substituted in a standard curve which is preset in a fluorescence analyzer; and finally, the concentration of an object to be measured in the sample can be automatically calculated and obtained by the fluorescence analyzer. The invention has high sensitivity, accurate quantization and easy operation.

The invention discloses a fast time-resolved immunoflourometric chromatographic test strip for quantitative detection as well as a preparation method and application thereof. The test strip comprises three parts including a Fusion 5 film, a cellulose nitrate film and water absorbing paper; by using a double-antibody sandwich method or a competition method principle, a time-resolved fluorescent microsphere is utilized as an immune marker to accurately and fast carry out quantitative detection on an antigen or antibody to be detected.

The invention discloses a test paper strip for the fluorescent bead immunochromatography of veterinary medicine remained in a detected sample and a preparation method thereof. A filter paper, a sample pad, a fiberglass membrane, a pyroxylin membrane and water sucking paper are sequentially stuck on a base plate in related joint; fluorescent beads are sprayed on the pyroxylin membrane for marking a veterinary medicine resistant molecule monoantibody; the pyroxylin membrane coated with a veterinary medicine molecule holoantigen is used as a detection region; the pyroxylin membrane coated with an anti-mouse antibody is used as a quality control region; and the test paper strip is prepared through the following steps: (1) the preparation of the pyroxylin membrane; (2) the preparation of a fluorescent bead pad; and (3) the assembling of the test paper strip. In the detecting process, emitted spectrums pass through a proper optical filter device; and all the emitted spectrums are collected through CCD scanning technology, are congregated, are multiplied and are analyzed through a fluorescence analyzer and relevant software to obtain a quantized fluorescence signal, thereby realizing quantitative detection. The test paper strip is mainly used for the qualitative detection and the quantitative detection of all the veterinary medicine classes in food safety detection.

A light emitting diode comprising of a fluorescent microsphere coating is proposed. The coating consists of fluorescent microspheres which fluoresce at green and red wavelengths, excited by a shorter wavelength LED. Due to the micron-scale dimension of the spheres, they are non-resolvable to the human eye and the overall optical output appears as color mixed. By varying the proportions of green and red fluorescent microspheres and the wavelength of the excitation source, the color of the optical output can be tuned. If the optical output has of blue, green and red components in the correct proportions, white color emission can be achieved. The light emitting diode can be sectioned into multiple individually-addressable regions. Each section can emit at a different wavelength according to the type of fluorescent microspheres coated. By varying the intensity of the blue, green and red regions by changing the bias voltage, the output wavelength (color) can be continuously tuned (varied).

The invention discloses immunofluorescence chromatography test paper for CRP (C-reaction protein) / SAA (Serum amyloid A protein) quantitative combined detection, aiming at providing a test strip capable of realizing quantitative combined detection on the content of CRP / SAA in human peripheral blood and quantitative combined detection on the content of CRP / SAA in venous blood. The immunofluorescence chromatography test paper is technically characterized by comprising a box with a cover, wherein a detection test strip and a blood diluent bottle are arranged in the box, the detection test strip comprises a bottom lining, the bottom lining is provided with a nitrocellulose membrane, one end of the nitrocellulose membrane is connected with a fluorescent microsphere marked antibody fixation pad, the fluorescent microsphere marked antibody fixation pad is connected with a sample pad, the other end of the nitrocellulose membrane is connected with an absorption pad, the fluorescent microsphere marked antibody fixation pad is coated by a CRP monoclonal antibody and an SAA monoclonal antibody, a CRP detection line coated by a CRP monoclonal antibody, an SAA detection line coated by an SAA monoclonal antibody, and a quality control line coated by a goat-anti-mouse IgG polyclonal antibody are arranged on the nitrocellulose membrane in parallel. The immunofluorescence chromatography test paper belongs to the technical field of biological medicines.

The invention relates to magnetic fluorescent microspheres and a preparation method thereof. The particle size of the magnetic fluorescent microspheres is 5-10 mu m, the fluorescence excitation wavelength range is 400-700nm, and the fluorescence intensity is not reduced within 24h. The prepration method comprises the following steps: adding a swelling agent into monodisperse carboxylated polystyrene microspheres, and adding magnetic nano microparticles into a swelling system; shaking on a decolorization shaker for 12-48h; using mixed solution of cyclohexane and ethanol for cleaning sediment, and sequentially carrying out ultrasonic dispersion and centrifugal separation till supernatant liquid is colorless under an ultraviolet lamp; and saving a final sediment product in 1ml of liquor. Compared with the existing magnetic fluorescent microspheres, the magnetic fluorescent microspheres have the advantages of uniform and controllable diameter, good fluorescence stability, simple preparation process, multiple types of fluorescence codes and the like, and can not only carry out fast separation and purification on reactants by being applied in the biological macromolecular detection, but also simultaneously detect a plurality of target molecules in a sample to be detected in a reaction tube and a hole, thereby being widely applied in the fields of immunoassay, nucleic acid hybridization, genotype analysis and the like.

The invention discloses a fluorescent microsphere immunochromatographic testing card for testing five indexes of hepatitis b and a method for preparing the same. The testing card comprises a hepatitis b surface antigen test paper strip, a hepatitis b e surface antigen test paper strip, a hepatitis b surface antibody test paper strip, a hepatitis b e surface antibody test paper strip, and a hepatitis b core antibody test paper strip. Each test paper strip is formed by overlapping and bonding filter paper, a sample pad, a glass fiber film spray-coated with fluorescent microspheres, a cellulose nitrate film and water absorption paper on a bottom plate by glue in sequence, wherein the cellulose nitrate film is coated with antigens serving as a testing area and anti-rabbit antibodies serving as a quality control area; and during a test, after emitted fluorescent light passes a filter, the emitted spectrum is collected, accumulated and multiplied by the CCD scanning technology and then converted into a numerical signal, the numerical signal is multiplied by a correction factor, and the strength of the corrected fluorescent light is substituted in a standard curve of a fluorescence analyzer, so that the concentrations of the five indexes of hepatitis b of the sample can be automatically worked out. The test of hepatitis b viruses by the testing card has the characteristics of specificity, sensitivity, simpleness and accuracy.

The invention discloses a double detection line SAA (Serum amyloid A protein) immunofluorescence chromatography quantitative detection reagent and a preparation method thereof. The double detection line SAA immunofluorescence chromatography quantitative detection reagent can simultaneously promote sensitivity and detection scope and can be applied to clinical detection for SAA level in patients of acute inflammation and chronic inflammation. According to the technical key points, the reagent comprises a base plate, a combining cushion, a coating film and an absorbing cushion, wherein a sample cushion is connected with the base plate; anti-SAA monoclonal antibody 1 and chick IgY are sprayed on the combining cushion and are marked with a same fluorescent microsphere; a detection line T1, a detection line T2 and a quality control C line are arranged on the coating film; anti-SAA monoclonal antibody 2 is coated with the detection line T1; antigen SAA protein is coated with the detection line T2; goat-anti-chick IgY is coated with the quality control C line. The reagent belongs to the technical field of in-vitro diagnostic reagents.

This invention relates to a suspension chip technology for the gene test to human papillomavirus used in testing and typing 26 kinds of papillomaviruses, in which, specific probes of which are crosslinked on 26 kinds of fluorescent microspheres to be reacted with the tested specimens then reacted with the report molecules labeled by the fluorescein to test the type specific nucleic acid of the virus by a fluorescent test device, which can test 26 kinds of ordinary HPV once and increases the test efficiency greatly and overcomes the shortcoming of missing testing the potential infections in the serology and immunity test method to realize early diagnosis to HPA diseases.

The invention relates to the field of fluorescence immunochromatography technique in medical immunology, specifically to a procalcitonin detection kit and a procalcitonin detection method. The detection kit is provided with a test cassette and is characterized in that the test cassette is successively provided with, from bottom to top, a PVC plate, a sample pad, a combination pad, a cellulose nitrate film and a water-absorbing pad, wherein a procalcitonin monoclonal antibody labeled by a rare earth fluorescent microsphere is adsorbed on the combination pad, the rare earth fluorescent microsphere has a diameter of 60 to 120 nm, is doped by rare earth lanthanide, is stable in a ground state and emits fluorescent light with a wavelength in a range of 540 to 600 nm under the action of an excitation light source in a wavelength range of 340 to 380 nm, and the monoclonal antibody is a purified mixed monoclonal antibody and is originated from monoclonal antibody cell strains directed at 2 to 6 different procalcitonin antigen epitopes. The procalcitonin detection kit has the advantages of simple operation, rapid reaction, high sensitivity, strong specificity, etc.

The invention relates to a method for preparing a polymer fluorescent microsphere. The method comprises the following steps of: 1, preparing polymer fluorescent microsphere liquid drops, namely dissolving a first polymer into a solvent, adding a fluorescent material into the solvent, magnetically and uniformly stirring the fluorescent material and the first polymer in the solvent to prepare a non-continuous phase, respectively putting the non-continuous phase and a continuous phase into injectors connected with a non-continuous phase inlet and a continuous phase inlet of a microfluid device, adjusting the flowing speeds of the two phases of solutions through a trace sample injection pump, so as to obtain the fluorescent microsphere liquid drops, and at a microfluid outlet, collecting the fluorescent microsphere liquid drops into a fluorescent microsphere receiving device; and 2, preparing the polymer fluorescent microsphere, namely drying the fluorescent microsphere liquid drops until the solvent is completely volatilized, then washing the fluorescent microsphere liquid drops by a washer, and cleaning the continuous phase of solution to finally obtain the polymer fluorescent microsphere. Equipment used by the method is simple and convenient to operate; the particle size of the microsphere can be adjusted by adjusting the flowing speeds of the continuous phase and the non-continuous phase; and the uniformity of the particle sizes of the prepared microspheres is high.

The invention relates to a preparation method and an application of a spectinomycin fast time-resolved fluoroimmunoassay quantitative detection test strip. The test strip consists of a Fusion5 membrane, a nitrocellulose membrane and water absorption paper; quick and fast quantitative detection is performed on the antigen to be detected by taking a time-resolved fluorescent microsphere as an immune marker based on the principle of competition law.

The invention discloses an immunofluorescence detection test strip and a preparation method thereof for rapid quantitative detection of porcine epidemic diarrhea viruses. The test strip comprises a sample cushion, a combination cushion, a chromatography film and a water-absorbing cushion, wherein the combination cushion is provided with a fluorescent microsphere labelled anti-PEDV (Porcine Epidemic Diarrhea Viruses) single-domain antibody; the single-domain antibody has high specificity and high sensibility against the antigen PEDV. The test strip is used for detecting PEVD viruses in breeding pig manure or PEDV pollution in feeding stuff plasma proteins on the basis of the newfound immunology principle of the specific single-domain antibody and antigen, can be used for on-site rapid detection or laboratory detection by simply taking 5-10 min; when the test strip is used in combination with a fluorescence quantitative detector, quantitative detection can be realized; the test strip is simple and convenient to operate, operators don't need professional training, a special laboratory is not needed, the limitation of the conventional detection method is overcome, and the test strip has good market prospects.

The present invention provides a preparation method of an uniform-size nanoparticle fluorescent microsphere. The density of fluorescent nanoparticle colloidal aqueous solution of the microsphere is adjusted to the micro-mol level so as to obtain the colloidal solution evenly scattered in the aqueous solution; the evenly scattered colloidal solution in the aqueous solution is injected into oil-phase solvent through capillary at the speed of 0.5 to 1.25 percent Vs / min so as to form droplets and Vs is the volume of the oil-phase solvent; the oil-phase solvent adopts bi- or multi-mixture with the solubility between 2 to 10 percent and the density equal to the density of water; containers and reflux pipes adopt the hydrophobic material; the water in droplets is absorbed by the oil phase and the nanoparticles form a dense sphere; an absorbent continuously absorbs the water dissolved in the oil phase, so that the water content in the oil phase is far lower than the saturation; the nanoparticle polymer with the size from dozens of nano to hundreds of nano, the spherical height higher than 5 percent and the size error less than 10 percent is obtained through regulating the density of the quantum pot colloidal solution and the velocity of the reflux pipe.

The invention relates to a synthetic method for micro-size polymer fluorescent microspheres and aims to solve the problem of limited application range since the size of fluorescent microspheres is only defined between nanometer and submicron. The synthetic method comprises the following steps: firstly, synthesizing Na2SeSO3 solution; secondly, synthesizing quantum dots QDs1 with high quality; thirdly, preparing pure quantum dots QDs2; fourthly, adding the quantum dots QDs2 in styrene solution for shaking; fifthly, adding polyvinylpyrrolidone and absolute ethyl alcohol in a four-necked flask, then feeding N2 into the four-necked flask, and dripping the styrene solution to obtain an emulsion sample after polyreaction; and sixthly, performing centrifugal settling, washing and drying to the emulsion sample to obtain polystyrene microspheres. The quantum dots are wrapped in the polymer microspheres by the dispersion polymerization method to obtain 1-10 mu.m fluorescent microspheres, the fluorescent microspheres can be applied to the field of biomarkers, coating fillers, optical encoders and the like, and the method can be used for the synthesis of fluorescent microspheres.

The invention aims at providing a simple and efficient method for preparing a high-performance magnetic fluorescent composite microsphere. Due to the existence of Fe3O4 magnetic nanoparticles, electrons of a fluorescent substance which are located at a conductance band are subjected to electron transfer in a process of returning to a valence band, the electrons of the conductance band are transferred on the Fe3O4 magnetic nanoparticles and fluorescence is subjected to quenching. The method provided by the invention is emphasized on solving the problem that the Fe3O4 magnetic nanoparticles cause large influence on the fluorescence performance of the fluorescent substance in a process of preparing a magnetic fluorescent microsphere. According to the preparing method provided by the invention, through changing a doping sequence and adopting different doping methods, the prepared magnetic fluorescent microsphere can minimize the influence on the fluorescent substance caused by magnetism on the basis of ensuring the magnetic fluorescent microsphere to have excellent magnetic property in actual use and enable the fluorescence performance to be optimal; and the fluorescent substance is introduced by adopting a high-temperature swelling method, so that fluorescent substances inside the microsphere cannot leak, and the stability of fluorescent signals is ensured. The mean particle diameter of the prepared magnetic fluorescent composite microsphere is 5-50 microns, and the particle diameter is even and has perfect appearance.

The invention discloses a preparation method of a polystyrene fluorescent microsphere coupled with an antibody, which comprises the following steps: 1. activating a carboxyl group on the surface of a fluorescent microsphere; 2. coupling an amino group of a monoclonal antibody with the carboxyl group on the surface of the fluorescent microsphere; 3. blocking activated groups not subjected to complete reaction on the surface of the fluorescent microsphere; and 4. preserving the polystyrene fluorescent microsphere coupled with the antibody. The preparation method disclosed by the invention is simple, easy to implement, low in cost and suitable for industrialization.

The invention discloses microspheres with high fluorescence intensity and a preparation method for the microspheres. The preparation method comprises: dispersing oil soluble quantum dots and macromolecular mesoporous microspheres in chloroform; and by taking a maleic anhydride copolymer as a surface activity mediating molecule, adding an alkaline aqueous solution or an amine compound, wherein the oil soluble quantum dots enter into ducts of the macromolecular mesoporous microspheres so as to obtain the fluorescent microspheres with abundant carboxyl functional groups on the surface. Compared with a conventional swelling method, according to the fluorescent microspheres prepared by the preparation method, the fluorescence intensity is improved by over 10 times, and the fluorescent microspheres have abundant functional groups on the surface, so that the fluorescent microspheres are favorably applied to the downstream biomedical field.

The present invention relates to the biologic technology field, and discloses a liquid phase albumen chip and the preparation and the usage method thereof which can simultaneously test human serum carcinoma embryonic antigen (CEA), Alpha fetoprotein (AFP), and hepatitis B surface antigen (HBsAg). The present invention couples the specificity antibody of CEA, AFP, and HBsAg on different fluorescence micro-spheres, and uses the test antibody marked by biotin or phycoerythrin to determine the nature quickly and quantitatively analyze the above three indexes with the double antibody sandwich method. The present invention uses the filtering membrane board when testing, and washes the board 3 times after each reaction is finished to increase the signal and improve the sensitivity. The present invention has high sensitivity, strong specificity, stable result, excellent repeatability, and simple operation; 1 micro liter serum sample can test three indexed simultaneously. The present invention is applicable to the health test and the general examination as well as the clinic test of the high risk population, and can facilitate the early diagnosis and the early treatment of the knub.

The invention discloses a kit for time resolution fluorescent quantitative detection on PCT. The kit comprises a fluorescent microsphere antibody complex and an immune fluorescent test paper card, wherein the fluorescent microsphere antibody complex is prepared by marking rare earth fluorescent microsphere with a PCT monoclonal antibody to form a compound and adding the compound on a pipette tip, and is used as a detection antibody after freeze-drying; the immune fluorescent test paper card comprises a detection test paper card; the detection test paper card consists of a sample pad, a nitrocellulose membrane and a water absorbing pad which are adhered to a lining plate in sequence in a lap joint manner; the position of a detection line on the nitrocellulose membrane is wrapped by another PCT monoclonal antibody; the position of a quality control line is wrapped by goat anti-mouse polyclonal antibody. By adopting the kit, the fluorescence influence caused by a sample self can be avoided, the rare earth fluorescent microsphere is adopted as a marking carrier, good stability can be achieved, the microsphere can be connected with the antibody through a covalent bond, and a stable marking product can be generated. The kit is rapid, simple and convenient in detecting the sample and high in sensitivity, and full quantitative detection can be achieved.

The invention provides a method for quantitative determination of an associated antigen by means of immunomagnetic beads. The method comprises the steps of coating an antibody with the beads in a coupling mode to obtain a bead solution of the coupled and coated antibody, mixing the bead solution of the coupled and coated antibody with a sample containing the associated antigen so that the antigen can be combined with the antibody coupled to the beads through specific immunity reaction, then adding an antibody solution marked with fluorescent microspheres so that specific immunity reaction can be conducted on the antibody marked with the fluorescent microspheres and the antigen on the beads, and detecting a fluorescence signal to obtain the content of the antigen. The detection method has the advantages that sensitivity is high, specificity is high, the problem that a certain kind of antibody is not coated firmly in certain occasions can be solved, quick detection of antigens can be achieved, stability is high, and detection results are accurate.

The invention relates to the field of clinical diagnosis, in particular to a time-resolved fluorescence immunochromatographic reagent for rapid quantitative simultaneous detection of cTnI, CKMB and Myo, and a preparation method thereof. The reagent comprises a test strip and fluorescent liquid, wherein the test strip comprises a bottom plate, Fusion5, a nitrocellulose membrane and an absorbent pad, and the Fusion5, the nitrocellulose membrane and the absorbent pad are sequentially connected and fixed on the bottom plate in the horizontal direction. Time-resolved fluorescent microspheres are used to improve the fluorescence intensity and decrease background signals, and cTnI, CKMB and Myo indexes in whole blood, serum or plasma can be simultaneously and quantitatively detected, and a sample needs only 10 to 20mul. The test strip has the advantages of convenience, rapidness, simple operation, short detection time, strong specificity, high sensitivity and relatively accurate test results, and is suitable for rapid diagnosis of clinical POCT.

The invention relates to the technical field of fluorescence immunochromatography in medical immunology and particularly relates to a D-dimer detection kit and a D-dimer detection method. The D-dimer detection kit is provided with a test paper card and is characterized in that the test paper card is sequentially provided with a PVC plate, a sample mat, a combination mat, a nitrocellulose membrane and a water absorption mat from bottom to top, wherein a D-dimer monoclonal antibody marked with rare-earth fluorescent micro-spheres is adsorbed on the combination mat, the diameter of each rare-earth fluorescent micro-sphere is 60nm to 120nm, the rare-earth fluorescent microspheres are doped with a rare-earth lanthanide element, the rare-earth fluorescent microspheres are stable at a ground state, and the fluorescence with wavelength range of 540nm to 600nm can be transmitted under the effect of a 340nm-380nm excitation light source; the monoclonal antibody is a monoclonal antibody mixed after purification and is sourced from a monoclonal antibody cell line aiming at 2 to 6 different D-dimer antigen epitopes. The D-dimer detection kit has advantages of simplicity in operation, rapid reaction, high sensitivity, high specificity and the like.

The invention discloses a fluorescent microsphere lateral chromatographic detection strip for multiple joint inspection of trace target substances as well as a preparation method and application thereof. The fluorescent microsphere lateral chromatographic detection strip is characterized by comprising a soleplate, wherein the top of the soleplate is sequentially provided with a sample absorption pad, a combination pad, a chromatographic film and a piece of water absorption paper from left end to right end, the right end of the sample absorption pad is pressed to be attached onto the left end of the combination pad, the right end of the combination pad is pressed to be attached onto the left end of the chromatographic film, the left end of the water absorption paper is pressed to be attached onto the right end of the chromatographic film to form a lateral chromatographic detection structure; the chromatographic film is provided with a detection line and a quality control line from left to right; the combination pad is formed by a polyester fiber film and fluorescent microspheres marked with different ligands on the polyester fiber film, and the chromatographic film consists of a nitrocellulose film and a plurality of detection lines which are arranged on the nitrocellulose film and contain different ligands which can be specifically combined with the target substances. The fluorescent microsphere lateral chromatographic detection strip can be used for performing multiple joint inspection on a plurality of trace target substances simultaneously, all display results have no cross reaction and are dependent from one another, the detection sensitivity and accuracy can be remarkably improved, rapidness and convenience in operation can be realized, and an important significance on biological detection and early diagnosis and treatment of diseases can be achieved.

The invention discloses a test strip for fluorescence immunochromatography of myeloperoxidase. The test strip comprises a base plate, a sample pad, a binding pad, a nitrocellulose membrane and an absorbent pad, and the sample pad, the binding pad, the nitrocellulose membrane and the absorbent pad are assembled on the base plate in a sequential overlapping manner, wherein the absorbent pad and thebinding pad are respectively pressed on two ends of the nitrocellulose membrane in an overlapping manner, and a detection area is formed on the surface of the nitrocellulose membrane; the sample pad is pressed on the binding pad in an overlapping manner, and a myeloperoxidase antibody-fluorescent microsphere compound is immobilized on the binding pad; and the nitrocellulose membrane in the detection area is coated with a detection line formed by a monoclonal antibody for recognizing another epitope of myeloperoxidase and a control line formed by a goat anti-mouse IgG polyclonal antibody. The test strip has the advantages of high sensitivity, high stability, realization of the detection linearity being 3.125-600 ng / ml, no non-specificity, short detection time of 5 min, realization of bedside quick test, and great improvement of the clinical diagnosis efficiency.

The invention discloses nano-grade fluorescent microspheres, a preparation method thereof, and a purpose thereof. The nano-grade fluorescent microspheres have core-shell structures, and have particle sizes of 200-500nm. The cores are polymer microspheres containing fluorescence molecules, and the shells have one or more functional groups modified on the outer surfaces of the polymer microspheres. The polymer microspheres are polymethyl methacrylate microspheres, or microspheres formed by copolymers produced by copolymerization of methyl methacrylate and other monomers, or a mixture thereof. The weight of the methyl methacrylate units at least accounts for 50% of the total weight of the nano-grade fluorescent microspheres, and the weight of the fluorescence molecules accounts for 0.05-5% of the total weight of the nano-grade fluorescent microspheres. The nano-grade fluorescent microspheres provided by the invention are advantaged in stable particle sizes. The spectrum of the nano-grade fluorescent microspheres is suitable for visible emission lights. The immunity chromatography method employing the nano-grade fluorescent microspheres as markers is convenient, fast, and highly sensitive. With the method, quantitative detection can be carried out.