Nanoscale organic and polymeric field-effect transistors as chemical sensors.

This article reviews recently published work concerning improved understanding of, and advancements in, organic and polymer semiconductor vapor-phase chemical sensing. Thin-film transistor sensors ranging in size from hundreds of microns down to a few nanometers are discussed, with comparisons made of sensing responses recorded at these different channel-length scales. The vapor-sensing behavior of nanoscale organic transistors is different from that of large-scale devices, because electrical transport in a nanoscale organic thin-film transistor depends on its morphological structure and interface properties (for example injection barrier) which could be modulated by delivery of analyte. Materials used in nanoscale devices, for example nanoparticles, nanotubes, and nanowires, are also briefly summarized in an attempt to introduce other relevant nano-transducers.