Patent ID: 7432113

Claim:
A method for detecting an analyte in a sample comprising: contacting the sample containing the analyte with a plurality of surface modified metallic colloids, wherein the analyte comprises a biomolecule, wherein the surface modified metallic colloids are prepared by contacting metal cations with a reducing agent in aqueous solution, subsequently heating the aqueous solution and attaching a bifunctional organic molecule to a metallic surface of the surface modified metallic colloids, wherein the bifunctional organic molecule has a moiety that has an affinity for the metallic surface and another moiety that has an affinity for the biomolecule, wherein the biomolecule of the analyte binds to said another moiety that has an affinity for the biomolecule of the surface modified metallic colloids, and detecting SERS signals emitted by the analyte, wherein the signals are indicative of the presence of the analyte.