Realization of a Localized Surface Plasmon Resonance Gas Sensor, Based on Ag nanoparticles

Here, the response of localized surface plasmon resonance (LSPR) gas sensor has been investigated, which consists of Ag nanoparticles on glass. Output characteristic of the proposed LSPR gas sensor are investigated by exposure of different concentrations of N2 to the structure (0-250 ppm). Ag nanoparticles are synthesized chemical method, which has been optimized in order to achieve the best detection sensitivity in the output behaviour of the sensor. It is shown that the best output response is achieved for Ag nanoparticles with the diameter of about 30 nm and LSPR peak at wavelength of about 415 nm. Physical adsorption of N2 molecules on Ag nanoparticles increases the refractive index of the enclosing environment, and leads to a red-shift in the wavelength of localized surface plasmons. It is illustrated here that the shift of the LSPR spectrum is sensitive to the concentration of exposed nitrogen, with a sensitivity of about 0.56 nm versus gas concentration variation of about 100 ppm. Our experimental investigations are in agreement with the simulation results, relating to the similar structure.