Biosensors based on EGOFETs

Acreo develops manufacturing techniques for the biosensors developed in the BioEGOFET project. The BioEGOFET sensor combines the specificity of a defined bio-probe with the high sensitivity of a field-effect transistor. It is based on an organic semiconductor layer on top of which a bio-recognition element is attached. The semiconductor, in turn, is included in an organic field-effect transistor (OFET) that utilizes an aqueous solution as its gate dielectric. The aqueous solution carries the analyte to the bio-recognition elements on the transistor channel. The idea is to create a sensitive structure which operates at low voltages. Further information about electrolyte-gated transistors is given here. Moreover, low-cost sensor devices will be provided through in-foil implementation, using rational manufacturing techniques such as printing.

A copolymer, which combines FET operation with the possibility of chemical grafting of the bio-recognition elements, has been synthesized.

Three different strategies for immobilization of biorecognition elements are investigated in parallel. Either avidin will be attached directly to biotin groups on the semiconductor surface, or avidin/antibody fragments will be attached to biotin/maleimide and embedded in a hydrophilic repellent polymer host matrix. A third approach is to couple avidin to a phospholipid bilayer produced by fusion of vesicles on the semiconductor. C-reactive protein has been chosen as a target molecule for the real application.