A high sensitive NO2 gas sensor based on PEDOT–PSS/TiO2 nanofibres

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 NO2 by CrO3, 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 H2O, CO2 and O2. 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 TiO2 fibres and the conductive polymer.