High-speed gas sensing using localized surface plasmon resonance of sputtered noble metal nanoparticles

High speed gas sensing devices can be applied in a number of areas where a better understanding of gas distribution is needed, such as in environmental monitoring and safety-and security-related fields. In this paper, we present a localized surface plasmon resonance (LSPR) sensor that was realized using sputtered Au and Ag nanoparticles (NPs), which can be used in robots for high-speed gas detection. The NPs' LSPR response, a red-shift of the minimum transmittance in wavelength (δλ_min), and a decrease in the minimum transmittance (ΔT_min) for ethanol gas, were investigated and compared using Au and Ag NPs under the same sputtering conditions but using a different thermal annealing process for the reshaping of the NPs. The results obtained show that NPs with a larger aspect ratio can generate a large LSPR response. The response characteristics confirmed that this LSPR sensor can be used for high-speed gas detection.