Theoretical and Experimental Investigation on SPR Gas Sensor Based on ZnO/Polypyrrole Interface for Ammonia Sensing Applications

This work includes the exploitation of the laboratory-assembled SPR technique for the application of gas sensors at room temperature. The refractive index change at the interface of ZnO/polypyrrole with adsorption of gases (NH3) is the basis of the SPR gas sensor. The theoretical simulations were done to find out the optimum thickness of ZnO and polypyrrole composite films for sharp SPR reflectance values. Theoretical SPR curves obtained by changing the value of the thickness of gold nanoparticle film and incident wavelength are also presented in the manuscript. Experimental studies were done to validate the theoretical studies and discussions were done about the interaction of NH3 gas with prism/Au/ZnO/polypyrrole system. Here, ZnO/polypyrrole multilayer structure is the sensing layer to develop a highly efficient SPR-based NH3 gas sensor. The outcome of these results validates the significance of the SPR technique for the application of interaction of surface adsorbed analytes, with the interface of dielectrics and sensing material.

Automated summary

This study explores the application of laboratory-assembled SPR technique for gas sensors at room temperature. The SPR gas sensor is based on the refractive index change at the interface of ZnO/polypyrrole with adsorption of gases (NH3). Theoretical simulations and experimental studies were conducted to optimize the thickness of ZnO and polypyrrole composite films, and to validate the interaction of NH3 gas with the prism/Au/ZnO/polypyrrole system. The results emphasize the importance of SPR technique for the application of surface adsorbed analytes with dielectrics and sensing materials.