Ammonia gas sensor based on nanostructured thin film of PANI-DBSA

This paper presents the fabrication of ammonia gas sensor using nanostructured thin film of PANI-DBSA. First, the interdigitated electrodes (IDEs) of platinum (Pt) were patterned on the glass substrate by depositing Pt thin film of 80 nm thickness by RF sputtering technique in 100% Ar ambient using a 3 inch diameter Pt metal (99.999% pure) target, and, subsequently IDEs were patterned using conventional photolithography technique. The DBSA doped PANI has been synthesized by direct one step emulsion polymerization using aniline as monomer and characterization is done suing XRD, UV-Visible Spectroscopy, and SEM. The synthesized PANI-DBSA nanoparticles were deposited on IDEs patterned glass substrate to realize a nanostructured film using spin coater at 1500 rpm. Gas sensing has been done for ammonia gas at different concentration levels in the form of relative response, response time, recovery time and repeatability. The fabricated sensor detects ammonia at 1ppm level quantitatively and reversibly at room temperature operation. The fabricated PANI-DBSA thin film gas sensor exhibits good sensitivity and response time at various ppm levels of ammonia. (author)