Patent ID: 8021891

Claim:
A method of detecting the presence of a protein analyte, the method comprising: providing a plurality of non-covalent complexes between a plurality of nanoparticles and a fluorescent polymer, wherein each of the plurality of nanoparticles comprises an inner metallic core and a coating layer comprising a cationic ligand, wherein the fluorescent polymer comprises an anionic group, and wherein fluorescence of the polymer in the non-covalent complexes is quenched; mixing a sample to be tested for the presence of the protein analyte with the plurality of the non-covalent complexes under a condition such that, if the protein analyte is present in the sample, at least some of the fluorescent polymer is displaced by the protein analyte, thereby resulting in restoration of at least some of fluorescence of the fluorescent polymer; and measuring a fluorescence pattern of the resulting sample to determine the presence of the protein analyte.