Gold Nanoparticle-Sensitized Zinc Oxide Nanorods-Based Nitric Oxide Gas Sensors with High Sensitivity, Selectivity and Low Detection Limit

Development of a low-cost hand-held nitric oxide (NO) sensor with high selectivity, sensitivity and low detection limit is attractive for environment and health monitoring applications. NO gas sensor was fabricated using hydrothermally grown ZnO nanorods (ZnO NRs). The sensing performance like sensor response, sensitivity, detection limit has been improved significantly by attaching gold nanoparticles (Au NPs) with ZnO NRs. Au NPs were synthesized by chemical reduction method from gold chloride trihydrate. The attachment of Au NPs on nanorods was done by spin coating method. The maximum sensor response and sensitivity were obtained at [Formula: see text]C operating temperature with [Formula: see text]l gold loading. The interference study of the sensor was carried out with acetone, ammonia, carbon monoxide, hydrogen peroxide and propanol. It demonstrated high selectivity towards the interfering gases and high humid condition. Au-decorated ZnO NRs exhibited very low detection limit [Formula: see text][Formula: see text]ppb, which is attractive for biomedical applications.