title: A water-gated organic thin film transistor as a sensor for water-borne amines.
abstract: The p-type semiconducting polymer Poly(2,5-bis(3-hexadecylthiophen-2-yl)thieno[3,2-b]thiophene) (PBTTT) displays innate sensitivity to water-borne amines. We demonstrate this with the help of water-gated PBTTT thin film transistors (TFTs). When octylamine is added to the gating water, TFTs respond with a significantly reduced saturated drain current. Underlying TFT drift is minimised by initial conditioning, and remaining drift can be accounted for by normalising current response to the current level under purge immediately before exposure. Normalised current response vs. amine concentration is reproducible between different transistors, and can be modelled by a Langmuir surface adsorption isotherm, which suggests physisorption of analyte at the PBTTT surface, rather than bulk penetration. Same PBTTT transistors do not respond to 1- octanol, confirming the specific affinity between amines and thiophene- based organic semiconductors.
authors.affiliation: Physics & Astronomy, University of Sheffield, Hicks Building, Hounsfield Rd, Sheffield S3 7RH, UK. Electronic address: php11saa@sheffield.ac.uk.
authors.forename: Saud A
authors.initials: SA
authors.lastname: Algarni
authors.affiliation: Physics & Astronomy, University of Sheffield, Hicks Building, Hounsfield Rd, Sheffield S3 7RH, UK.
authors.forename: Talal M
authors.initials: TM
authors.lastname: Althagafi
authors.affiliation: Physics department, King Faisal University, Al-Ahsa, Saudi Arabia.
authors.forename: Abdullah Al
authors.initials: AA
authors.lastname: Naim
authors.affiliation: Physics & Astronomy, University of Sheffield, Hicks Building, Hounsfield Rd, Sheffield S3 7RH, UK.
authors.forename: Martin
authors.initials: M
authors.lastname: Grell
mesh_terms: D000588:Amines / Q000032:analysis*; D011108:Polymers; D012666:Semiconductors; D014173:Transistors, Electronic; D014867:Water
chemical_list: D000588:Amines; D011108:Polymers; D014867:Water
keywords: Biosensor; Octylamine; PBTTT; Thin film transistor