Expression of concern: Design and development of highly sensitive PEDOT-PSS/AuNP hybrid nanocomposite-based sensor towards room temperature detection of greenhouse methane gas at ppb level.

Expression of concern for 'Design and development of highly sensitive PEDOT-PSS/AuNP hybrid nanocomposite-based sensor towards room temperature detection of greenhouse methane gas at ppb level' by Syed Khasim et al., RSC Adv., 2021, 11, 15017-15029. DOI https://doi.org/10.1039/D1RA00994J.

Design and development of highly sensitive PEDOT-PSS/AuNP hybrid nanocomposite-based sensor towards room temperature detection of greenhouse methane gas at ppb level.

Herein, we present fabrication of a novel methane sensor based on poly (3,4-ethylenedioxythiophene:poly (styrene sulfonic acid)) (p-PEDOT-PSS) and gold nanoparticles (AuNPs) treated with dimethyl sulfoxide (DMSO) and Zonyl using a spin coating technique. The nanocomposite films were further post treated with H2SO4 to improve the charge transport mechanism. The structural and morphological features of the composites were analyzed through scanning electronic microscopy, transmission electron microscopy, Fourier transform infra-red spectroscopy, UV-Vis spectroscopy and thermogravimetric analysis. Treatment with organic solvents and post treatment of H2SO4 significantly enhances the conductivity of the composite to 1800 S cm-1. The fabricated sensor shows an excellent sensing response, fast response and recovery time along with acceptable selectivity towards methane gas at ppb concentrations. Due to a simple fabrication technique, excellent conductivity, superior sensing performance and improved mechanical properties, the sensor fabricated in this study could potentially be used to detect greenhouse methane gas at low concentrations.