Patent ID: 7888134

Claim:
A method of detecting an analyte of interest in a sample, the method comprising: (a) providing the sample; (b) providing an immunosensor device having a component apparatus for binding the analyte of interest in a sample, the apparatus comprising: (i) a solid substrate with an exposed surface; (ii) a compound provided as a layer bound on the solid substrate; and (iii) a plurality of recombinant single chain antibodies (scFv's) specific for the analyte of interest bound to the compound on the solid substrate, each scFv comprising: (A) an antibody variable light chain (V L ) polypeptide specific for an analyte, (B) an antibody variable heavy chain (V H ) polypeptide specific for the analyte, and (C) a linker polypeptide covalently linking the antibody variable light chain (V L ) polypeptide to the antibody variable heavy chain (V H ) polypeptide, the linker polypeptide having an amino acid sequence comprising one or more amino acids with sidechains that bind to the compound, wherein when the analyte of interest is present in the sample the scFv binds the analyte to the solid substrate; (c) applying the sample to the apparatus for a time sufficient for the scFv on the substrate to bind to the analyte if present in the sample; and (d) detecting the analyte bound to the scFv on the solid substrate with the immunosensor device.