DNA detection with a water-gated organic field-effect transistor

Laurent Kergoat (1) , B. Piro (1) , M. Berggren (2) , M. C. Pham (1) , A. Yassar (3) , G. Horowitz (3)

1 ITODYS (UMR_7086) - Interfaces, Traitements, Organisation et Dynamique des Systèmes
2 Organic Electronics, Dept. of Sciences and Technology (ITN), Linköpings Universitet, Bredgatan 33, SE-601 74 Norrköping, Sweden
3 LPICM - Laboratoire de physique des interfaces et des couches minces [Palaiseau]

A DNA sensor based on a water-gated organic field-effect transistor is described. The semiconductor is poly [3-(5-carboxypentyl)thiophene-2,5-diyl] onto which DNA probes are covalently grafted via NHS/EDC chemistry. Clear changes in the output characteristic of the device are observed upon DNA immobilization and after DNA hybridization. Experimental data point out the importance of the electrolyte Debye length that can screen negative DNA charges and impede transduction. For this reason, deionized water was used in order to increase the Debye length up to several hundreds of nanometers. In this case, a decrease in the off current was observed upon hybridization, whereas no significant change occurred when using saline solutions.

Domaines: Polymères; Matériaux; Electronique

Laurent Kergoat, B. Piro, M. Berggren, M. C. Pham, A. Yassar, et al.. DNA detection with a water-gated organic field-effect transistor. Organic Electronics, 2012, 13 (1), pp.1-6. ⟨10.1016/j.orgel.2011.09.025⟩. ⟨hal-00822266⟩