Organic biosensors based on PEDOT:PSS

Coffee Talks of MAterials physics and naNOscience

  • Data: 19 ottobre 2018 dalle 14:30 alle 15:30

  • Luogo: Sala Riunioni, piano 2, viale Berti Pichat 6/2, Bologna

Contatto di riferimento:

Partecipanti: Marta Tessarolo

Organic electrochemical transistors (OECT) have been proposed as biosensors for redox-active biomolecules thanks to their remarkable features such as signal amplification, very low operating potentials and adsorbed power. In our research group we developed all-PEDOT:PSS OECTs sensors for the selective detection of active bio-molecules in body fluids, such as: Dopamine, Adrenaline, Ascorbic Acid. The transistor configuration, fully based on a conductive polymer, allows to obtain low cost and flexible devices compatible with several applications from in in vivo analysis even to textile wearable chemical sensors.

Here we present recent results on new biosensors based on the functionalization of the PEDOT:PSS conductive polymer.  We report on a new device, we designed for detection of Cl- ions, based on PEDOT:PSS functionalized with Ag/AgCl nanoparticles (NPs). The Ag/AgCl NPs act as a gate electrode embedded into the conductive polymer channel and, as a consequence, our sensor combines an intrinsically amplified response with a simple two terminal electrical connection. To demonstrate our strategy, we investigate the novel composite material by electrostatic force microscopy, scanning electron microscopy and electrochemical impedance spectroscopy and show that the spontaneous interaction between the NPs and Cl- ions present in the sample solution is directly coupled to the charge transfer process into the semiconductor, inducing a fast modulation of the channel conductivity. Consequently, the current flowing in the channel is directly related to the logarithm of Cl- concentration.