Nitric oxide gas sensor based on electrospun tin oxide nanofibers surface-decorated by gold nanoparticles

The decoration of noble-metal remains an effective and general strategy to rejuvenate “old” sensing materials for targeted gases. Herein, gold was loaded onto electrospun SnO 2 nanofibers by a simple impregnation route and the resulting hybrids were employed to detect nitric oxide (NO). XRD, TEM, XPS and elemental mapping corroborated that metallic Au clusters were successfully anchored on the fiber surface. Owing to the spill-over effect, these clusters supply additional active sites and chemisorbed oxygen. Gas-sensing measurements revealed that, even at a relatively low operating temperature, the Au-decorated SnO 2 nanofibers delivered a striking response of 37.3 toward 200 ppb NO, whereas negligible cross-responses were observed to typical interferents in exhaled breath. Moreover, the sensor exhibited excellent repeatability and long-term stability. These results demonstrate the remarkable potential of Au surface functionalization for boosting the NO-sensing performance of SnO 2 nanofibers.