Gas visualization based on localized surface plasmon resonance of gold nanoparticle films

Localized surface plasmon resonance (LSPR) of metal nanoparticles (MNPs) causes strong light absorption and scattering, and the intensity changes are corresponding to refractive index of medium. Our research demonstrates that the spatial distribution of a gas flow can be visualized by observation of transmitted/scattered light of a LSPR-film which consists of two-dimensional arrangement of gold nanoparticles (AuNPs). In this study, to improve the visualization ability of LSPR-films, AuNPs are prepared under different conditions of annealing temperature and re-sputtering times. The LSPR character and gas responding ability are investigated. The results show that LSPR-film with annealing temperature 200°C and 3 times of sputtering shows the best performance. The film has ability to visualize the gas flow of ethanol with a concentration of 400ppm. It is suggested that high visualization ability can be achieved by controlling the distance of neighboring nanoparticles.