Patent ID: 8518329

Claim:
A biosensor system, comprising: a silicon substrate; active devices fabricated on said silicon substrate; a plurality of metal layers integrated on top and adjacent to said active devices; a passivation layer covering a top metal layer of said plurality of metal layers in order to protect said plurality of metal layers, wherein said passivation layer comprises an opening configured to expose said top metal layer to an environment, wherein said opening is used as a sensing electrode, wherein said sensing electrode is located in an electrolyte containing analytes, wherein said sensing electrode is configured to detect a change in an impedance at an interface between said sensing electrode and said electrolyte in response to an analyte of interest binding to one of said plurality of probes; and a plurality of probes attached to said sensing electrode, wherein said plurality of probes are impedance sensors; a detection circuitry residing on said silicon substrate, wherein said electrolyte containing analytes resides on top of said detection circuitry, wherein said detection circuitry is configured to measure said impedance at said interface between said sensing electrode and said electrolyte; an excitation source configured to generate sine waves; and an excitation electrode connected to said excitation source, wherein said excitation electrode resides in said electrolyte.