Sol-gel film opto-chemical sensor based on surface plasmon resonance

摘要

The sol-gel derived metal oxide semiconductor films have been used as sensing medium in the opto-chemical sensor based on SPR for the first time. Data simulation shows that the sensitivity of this scheme to refractive index of the films is predicted to be more than 10{sup}5. By adding an intermediate layer between the metal films and the sensing films, optimizing the optical parameters, the sensitivity of this sensor with optimal optical parameters can increase by 40% over that of only sensing films. Experimentally, we have selected SnO{sub}2 and SiO{sub}2 films as sensing and intermediate layers, and made the gas sensing tests to NH{sub}3, C{sub}2H{sub}5OH and C{sub}3H{sub}8. The sensor with optimized structure has a higher sensitivity, and the detection limits for these gases are available to 10{sup}(-1) ppm.