Theoretical study of hazardous carbon-di-oxide gas sensing using MIM structure-based SPR sensing scheme

This work mainly focussed on the sensing of the environmentally damaging gas carbon dioxide (CO2) by designing a gas sensor based on a surface plasmon resonance (SPR) principle. The proposed model is based on the metal-insulator-metal (MIM) model which mainly relies on metal thickness, dielectric thickness, and incident light wavelength. A comparative analysis between conventional as well as MIM-based structure is shown in this study and it is observed that by operating at 4400 nm incident light wavelength,the MIM-based structure shows sharp resonance curve, high resolution, minimum FWHM, and extremely high FOM. By using the modified Elden's formulae, the variation in refractive index is investigated by changing the numerical values of humidity, temperature, pressure, and CO2 content from the reference value, respectively. For each case, the sensitivity has been estimated. By using the proposed MIM-based structure, FOM value as high as 1273.11RIU(-1); at the end of this article, limit of detection (LOD) is calculated by varying the CO2 gas concentration.