Patent ID: 8084202

Claim:
A method for detecting a molecular recognition event comprising, providing a substrate having a surface wherein the surface has an array of electronic detectors wherein the electronic detectors are comprised of at least one drive electrode, at least one sensing electrode, and at least one reference electrode, wherein the at least one drive electrode is connected to both drive circuitry configured to drive polymer synthesis and an integrating charge amplifier, wherein a surface area of a drive electrode is larger than a surface area of a reference electrode, and wherein first nucleic acid molecules are attached to the surface of a sensing electrode; providing second nucleic acid molecules under conditions that allow the second nucleic acid molecules to hybridize to the first nucleic acid molecules wherein the second nucleic acid comprises two regions: one region that is substantially complementary to the first nucleic acid molecule and a second region that is not substantially complementary to the first nucleic acid molecule and wherein the second region that is not substantially complementary remains single stranded and available for further hybridization reactions after the first hybridization reaction with the first nucleic acid molecule; electronically detecting the hybridization reaction between the first and second nucleic acid molecules using the electronic detectors; providing third nucleic acid molecules that are substantially complementary to the second region of the second nucleic acid molecule under conditions that allow the third nucleic acid molecules to hybridize to the second region of the second nucleic acid molecule wherein the third nucleic acid molecules comprise an optically detectable label; and optically detecting the label of the third nucleic acid molecules.