Characterization of novel impedimetric pH-sensors based on solution-processable biocompatible thin-film semiconducting organic coatings

In this work, novel pH sensors based on biocompatible organic semiconductors are presented. The suitability of poly(3-hexylthiophene)(P3HT) and carbon nanotubes (CNTs) as sensing layers in aqueous media was investigated. The main advantage of this new form of pH sensors is their simplified architecture without a reference electrode. Good pH sensitivity was observed for both CNT sensors and P3HT sensors even with a small amount (60(l) of the analyte. Although the CNT-based sensors were more robust than the polymer-based ones, the stability of both sensors needs to be improved. In addition to the prospect of printing the sensors on thin and flexible substrates, the usage of solution processable materials enables a simple and low-cost fabrication of the devices. (C) 2012 Published by Elsevier B.V.