Patent ID: 7494820

Claim:
A method of determining the presence of an analyte of interest which binds to a chemical moiety, which comprises (a) forming a reagent mixture comprising the chemical moiety and a sample that may contain the analyte of interest; such that the chemical moiety and the analyte specifically bind to one another, said chemical moiety having the formula [MPL 1 L 2 -(-link-)-] t B wherein M is a lanthanide; P is a polydentate ligand of M; L 1 and L 2 are ligands of M, each of which may be a substance covalently bound to one or more of P, L 1 or L 2 through one or more covalent bond linkages, said linkages designated as (-link-) and being covalent bonds linking B with at least one of P, L 1 or L 2 ; t is an integer equal to or greater than 1; B is a biological substance or a synthetic substance which is capable of specifically binding to the analyte of interest; P, L 1 , L 2 , and B are of such number that the total number of bonds to M provided by the ligands of M equals the coordination number of M; and P, L 1 , L 2 , and B are of such composition that the chemical moiety can be induced to repeatedly emit electromagnetic radiation; (b) exposing the reagent mixture to electrochemical energy, the potential of which oscillates between a potential sufficiently positive and sufficiently negative to induce the chemical moiety to oscillate between at least two oxidization states, thereby inducing the chemical moiety to repeatedly electrochemiluminesce; and (c) detecting emitted luminescence thereby to determine the presence of the analyte of interest.