Field Effect Transistor Based on Solely Semiconducting Single-Walled Carbon Nanotubes for the Detection of 2-Chlorophenol

We report a promoted sensitivity to 2-chlorophenol (2-CP) molecules of a fabricated back gated, interdigitated electrode field effect transistor based on separated semiconducting single-walled carbon nanotubes (CNTFET). The origin of the interaction between the nanotubes that serve as channels across the source and drain contacts and organic volatile compound is suggested due to peculiarities gained after the nanotube separation technique. The semiconducting nanotubes that were used for building-up the CNTFETs had an average diameter of 1.4nm and have been separated by the efficient aqueous two-phase extraction technique. The advantage of the technique is in the one-step extraction of semiconducting type of conductivity nanotubes with high yield. Chlorophenols are widely studied due to the toxicity and hazardous health effects depending on the exposure. Previously chlorophenols were reported to be not interacting with pristine nanotubes. As prepared CNTFET device demonstrates a detection limit below 100 parts per million for the 2-CP molecules with a reaction time of 150 s. CNTFET devices have good repeatability, low bias stress, and electron charge carrier mobility of 17.5 +/- 0.1 cm(2) (Vs)(-1). We discuss possible physical mechanisms of the 2-CP adsorption induced current drop and potential ways to improve sensitivity.