Patent ID: 8603750

Claim:
A method for assaying an analyte, which method comprises: a) contacting a sample suspected of containing an analyte with a reactant labeled with a photoelectrochemically active molecule and capable of binding and/or reacting with said analyte under suitable conditions to allow binding of said analyte, if present in said sample, to said reactant; b) converting said photoelectrochemically active molecule with light to an excited state in the presence of an electrode having an energy level that is lower than the energy level of said excited state and a reducing agent incapable of receiving an electron from said excited state photoelectrochemically active molecule, to generate an electron transfer from said excited state photoelectrochemically active molecule to said electrode, thereby producing an oxidized photoelectrochemically active molecule at a ground state; c) converting said oxidized photoelectrochemically active molecule at a ground state by said reducing agent to a reduced photoelectrochemically active molecule at a ground state that can be again excited with light; d) repeating steps b) and c); and e) assessing an electric current generated by said electron transfer from said excited photoelectrochemically active molecule to said electrode to determine presence and/or amount of said analyte in said sample.