Highly sensitive and selective PAni-CeO 2 nanohybrid for detection of NH 3 biomarker at room temperature

An impressive room temperature (25 °C) NH 3 biomarker sensor has been developed using polyaniline (PAni)-CeO 2 nanohybrid by facile oxidative polymerization process on glass substrates. The structural properties of PAni-CeO 2 nanohybrids were disclosed using X-ray diffractometry, and the surface morphology was studied using field emission scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy techniques. The PAni-CeO 2 nanohybrids shows cubic crystal structure with strongly interconnected nanofiber surface morphology. The chemiresistive gas sensing performance of the PAni-CeO 2 nanohybrid sensor reveals that the CeO 2 nanoparticles (NPs) have a significant impact on the hybrid sensor. The CeO 2 NPs in the PAni-CeO 2 nanohybrid might block the charge carriers or reduce the delocalization length and hence increase the resistance of the nanohybrid when exposed to NH 3 gas. PAni-CeO 2 (50 wt%) nanohybrid sensor exhibits (80%) response toward 100 ppm NH 3 which is about four-fold higher than pristine PAni (26.70%), showing excellent stability (78.75%), admirable reproducibility with least response time (9.31 s), and such an excellent performance could be imputed to a high explicit surface area of CeO 2 for significant chemical interaction and the formation of interfacial heterojunction bond with CeO 2 , exploring PAni-CeO 2 (50 wt%) nanohybrid as a potential candidate for biomarker NH 3 detection. An impedance spectroscopy was used to investigate the interaction mechanism between the NH 3 gas and the PAni-CeO 2 nanohybrid sensor.