Among other things, the present disclosure is related to devices and methods of performing biological and chemical assays, such as but not limited to immunoassays and nucleic assay acid, particularly a homogeneous assay that does not use a wash step and that is fast (e.g., 60 seconds from dropping a sample to displaying results). The present disclosure is related to both competitive and non-competitive homogeneous assays.

The present invention relates to a method for detecting a target analyte using a gold nanoparticle, comprising growing a copper crystal specifically on a gold nanoparticle by treating the gold nanoparticle with a solution comprising a copper ion, a polymer having a primary or secondary amine group, and a reducing agent, a composition for amplifying a signal used in the detection method above, and a kit for detecting a target analyte comprising the composition for amplifying a signal above.

According to a pad which is used for an immunochromatographic device for extracting a substance to be detected contained in a detection target in an analyte with nitrous acid and which contains an acid anhydride having vapor pressure at 25° C. of 5×10.sup.−2 Pa or less and solubility in water at 25° C. of 0.1 mg/L or more, the storage stability is improved; a substance to be detected contained in an analyte is detected with high sensitivity; and the complexity of production is reduced.

Methods are herein described which reduce the non-specific light scattering background from polymeric microspheres in aqueous suspension to a level where individual metal or metal-like plasmonic nanoparticles that have been chemically bound to the surface of individual polymeric microspheres can be imaged by high resolution optics and enumerated by image analysis software. The non-specific light scattering background is reduced by employing aqueous-miscible solvents to remove residual water at the microsphere surfaces and resuspending the microspheres in a fluid having a refractive index substantially similar to the refractive index of polymeric microspheres. Embodiments of the method disclosed herein enable sensitive quantitative assays for ligand receptor binding, antigen antibody binding and nucleic acid hybridization binding. The embodiments disclosed herein further may employ polystyrene microspheres and gold plasmonic nanoparticles.

The present invention relates to a method of detecting one or more tissue-derived aggregated proteins in a biological sample.

The disclosure includes a method for determining an analyte in a sample in an interaction assay, including contacting a sample with an interaction modulator, wherein the interaction modulator is Poly-(4-styrenesulfonic acid-co-maleic acid) (PSSM), aminodextran, carboxymethyldextran, Poly-(2-acrylamido-2-methyl-1-propanesulfonic acid (PAMPS), triethylamine, triethanolamine, taurine, or dodecylsulfate. The disclosure includes a method for determining an analyte in an interaction assay, including contacting the sample with an interaction modulator, wherein the interaction modulator is an enhancer of the interaction assay at low analyte concentrations and is a retarder of the interaction assay at high analyte concentrations and wherein the interaction modulator is Poly-(4-styrenesulfonic acid-co-maleic acid) (PSSM) and/or Polyacrylic acid (PAA). The disclosure further relates to a kit having a detection agent specifically detecting an analyte and at least one interaction modulator. Further, the present disclosure relates to devices relating to the methods and kits.

The present invention provides an improved method of quantitative and/or qualitative analysis of a target molecule using nitrocellulose membrane (NCM). In particular, the present invention provides a porous nitrocellulose membrane that includes a surface and an organic nanostructured molecule that is non-covalently attached to the surface of NCM. The organic nanostructured molecule has a branched region that includes a plurality of terminal region (e.g., terminal end) moieties that are non-covalently attached or bound to a surface of the porous NCM. The organic nanostructured molecule also comprises a linear region that includes a covalently attached capture molecule that is adapted to selectively bind to a target molecule. The NCM of the invention provides an improved reproducibility, reliability, and selectivity compared an NCM in the absence of the organic nanostructured molecule.

Methods of mitigating lipoprotein interference in in vitro diagnostic assays for target hydrophobic analytes are disclosed, as well as compositions, kits, and devices useful in said methods. A pretreatment reagent is utilized that includes at least one enzyme that digests lipoprotein.

Among other things, the present disclosure is related to devices and methods of performing biological and chemical assays, such as but not limited to immunoassays and nucleic assay acid, particularly a homogeneous assay that does not use a wash step and that is fast (e.g., 60 seconds from dropping a sample to displaying results). The present disclosure is related to both competitive and non-competitive homogeneous assays.

The present invention provides a method of assaying a sample solution for the presence of a first analyte comprising: (a) providing a sensor surface having a ligand immobilized thereto; (b) flowing the sample solution over the sensor surface; and (c) detecting the presence or absence of binding of the analyte to the ligand on the sensor surface; wherein the contact time between the sample solution and the immobilized ligand is less than 15 seconds.