Addressable transistor chip for conducting assays

A chip for detecting the presence of at least one analyte, comprising:

• a substrate;
• a plurality of organic field effect transistors, arranged in a two dimensional array on said substrate, each of said organic field effect transistors including:
• a first and second electrodes printed on the substrate;
• and a channel extending between the first and second electrodes;
• an organic semiconducting material filling the channel;
• a dielectric layer formed atop the first and second electrodes and the channel;
• a third electrode in proximity with the first and second electrodes and isolated therefrom, wherein each of said field effect transistors further comprises an exposed electrolyte coated atop of its dielectric layer and in contact with its third electrode, said dielectric layer electrically insulating said channel from said exposed electrolyte, said exposed electrolyte, exposed to receive an analyte, whereby the presence of the analyte when received on the exposed electrolyte atop of the dielectric layer of the field effect transistor influences electrical characteristics of the channel under modulation of the third electrode, and may be detected through the first and second electrodes, and
• a hydrophobic coating covering the remaining surface of said substrate not covered by said electrolyte.