A high sensitive NO_2 gas sensor based on PEDOT-PSS/TiO_2 nanofibres

摘要

A hybrid electrospun nanofibrous framework of titania, generated at first by growing up the nanofibres directly onto an interdigitated electrode (IDE) as a transducer and then coating them with an ultra-thin film of PEDOT-PSS, was investigated as a potential sensing material for NO. The stoichiometric oxidation of NO into NO_2 by CrO_3, allowed the conductometric sensor to detect analyte concentrations down to 1 ppb, then being suitable for asthma monitoring. The sensing features were assessed by following the sampling procedures specified by the ATS-ERS guidelines, and testing potential interfering substances such as H_2O, CO_2 and O_2. The resulting sensor performances seemed to be mainly related to the peculiarity of the framework structure (through AFM, SEM, TEM and MIA investigations) and to the phenomena occurring at the interface between the TiO_2 fibres and the conductive polymer.