title: Biorecognition in Organic Field Effect Transistors Biosensors: The Role of the Density of States of the Organic Semiconductor.
abstract: Biorecognition is a central event in biological processes in the living systems that is also widely exploited in technological and health applications. We demonstrate that the Electrolyte Gated Organic Field Effect Transistor (EGOFET) is an ultrasensitive and specific device that allows us to quantitatively assess the thermodynamics of biomolecular recognition between a human antibody and its antigen, namely, the inflammatory cytokine TNFα at the solid/liquid interface. The EGOFET biosensor exhibits a superexponential response at TNFα concentration below 1 nM with a minimum detection level of 100 pM. The sensitivity of the device depends on the analyte concentration, reaching a maximum in the range of clinically relevant TNFα concentrations when the EGOFET is operated in the subthreshold regime. At concentrations greater than 1 nM the response scales linearly with the concentration. The sensitivity and the dynamic range are both modulated by the gate voltage. These results are explained by establishing the correlation between the sensitivity and the density of states (DOS) of the organic semiconductor. Then, the superexponential response arises from the energy-dependence of the tail of the DOS of the HOMO level. From the gate voltage-dependent response, we extract the binding constant, as well as the changes of the surface charge and the effective capacitance accompanying biorecognition at the electrode surface. Finally, we demonstrate the detection of TNFα in human-plasma derived samples as an example for point-of-care application.
authors.affiliation: Dipartimento di Scienze della Vita, Università di Modena e Reggio Emilia , Via Campi 103, 41125 Modena, Italy.
authors.forename: Marcello
authors.identifier: 0000-0002-3356-8829
authors.initials: M
authors.lastname: Berto
authors.affiliation: Dipartimento di Scienze della Vita, Università di Modena e Reggio Emilia , Via Campi 103, 41125 Modena, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Casalini
authors.affiliation: Dipartimento di Scienze della Vita, Università di Modena e Reggio Emilia , Via Campi 103, 41125 Modena, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Di Lauro
authors.affiliation: Dipartimento di Scienza Applicata e Tecnologia (DISAT), Politecnico di Torino , C.so Duca degli Abruzzi 24, 10129 Torino, Italy.|IMEM-CNR, Parco Area delle Scienze 37, 43124 Parma, Italy.
authors.forename: Simone L
authors.initials: SL
authors.lastname: Marasso
authors.affiliation: Dipartimento di Scienza Applicata e Tecnologia (DISAT), Politecnico di Torino , C.so Duca degli Abruzzi 24, 10129 Torino, Italy.|IMEM-CNR, Parco Area delle Scienze 37, 43124 Parma, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Cocuzza
authors.affiliation: Istituto Italiano di Tecnologia , Center for Sustainable Futures, Corso Trento 21, 10129 Torino, Italy.
authors.forename: Denis
authors.initials: D
authors.lastname: Perrone
authors.affiliation: Dipartimento di Scienze della Vita, Università di Modena e Reggio Emilia , Via Campi 103, 41125 Modena, Italy.
authors.forename: Marcello
authors.initials: M
authors.lastname: Pinti
authors.affiliation: Dipartimento di Scienze Mediche e Chirurgiche Materno-Infantili e dell'Adulto, Università di Modena e Reggio Emilia , Via Campi 287, 41125 Modena, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Cossarizza
authors.affiliation: Dipartimento di Scienza Applicata e Tecnologia (DISAT), Politecnico di Torino , C.so Duca degli Abruzzi 24, 10129 Torino, Italy.|Istituto Italiano di Tecnologia , Center for Sustainable Futures, Corso Trento 21, 10129 Torino, Italy.
authors.forename: Candido F
authors.initials: CF
authors.lastname: Pirri
authors.affiliation: Laboratory of Organic Electronics, Department of Science and Technology, ITN, Linköping University , S-601 74 Norrköping, Sweden.
authors.forename: Daniel T
authors.identifier: 0000-0002-2799-3490
authors.initials: DT
authors.lastname: Simon
authors.affiliation: Laboratory of Organic Electronics, Department of Science and Technology, ITN, Linköping University , S-601 74 Norrköping, Sweden.
authors.forename: Magnus
authors.initials: M
authors.lastname: Berggren
authors.affiliation: Dipartimento di Chimica "G. Ciamician", Università di Bologna , Via Selmi 2, 40126 Bologna, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Zerbetto
authors.affiliation: Dipartimento di Scienze della Vita, Università di Modena e Reggio Emilia , Via Campi 103, 41125 Modena, Italy.
authors.forename: Carlo A
authors.identifier: 0000-0002-5701-5727
authors.initials: CA
authors.lastname: Bortolotti
authors.affiliation: Dipartimento di Scienze della Vita, Università di Modena e Reggio Emilia , Via Campi 103, 41125 Modena, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Biscarini
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D025802:Electric Capacitance; D004867:Equipment Design; D006801:Humans; D056656:Lab-On-A-Chip Devices; D012666:Semiconductors; D013816:Thermodynamics; D014173:Transistors, Electronic; D014409:Tumor Necrosis Factor-alpha / Q000097:blood*
chemical_list: D014409:Tumor Necrosis Factor-alpha