Abstract

Electronic transduction can open new perspectives for point-of-care diagnosis and treatment monitoring. In this respect, label free, organic field-effect transistor (OFET) sensors have recently raised the interest of the organic-electronic community. The EGOFET biosensor aims at an electronic transduction of a bio-recognition event, eventually leading to an amplified response. The sensor combines the specificity of a defined bio-probe with the label-free and high sensitivity of the field-effect transduction principle. The recognition will be achieved through antigens, antibodies or membrane proteins placed on top of the organic semiconductor, right where the electrical transport occurs in this dielectrics/oxide-free structure. Supramolecular architectures will be used to immobilize the bio-probes into polymeric or phospholipid layers to maximise recognition capabilities and minimize non-specific binding and fouling. High sensitivity will be achieved by exploiting conformational changes and/or charge generation effects occurring upon the recognition process. To attain low-operating voltage and low-power consumption, the OFET will take advantage of the high capacitance offered by the electrolytic or protonic medium used to carry the analyte up to the semi-conductor surface. Implementation of the devices on paper and plastic substrates will be realized by low-cost printing-compatible technologies. The sensors figures of merit will be assessed by exploiting the highly specific biotin/avidin affinity reaction. A proof-of-principle for a point-of-care relevant application, using the immunoassay approach, will be pursued afterwards.