Conductivity-Based Gas Sensors Using Tamarindus indica Polysaccharide-Capped Gold Nanoparticles for the Detection of Volatile Gases

Abstract

Gold nanoparticles (nAu) were synthesized by a sustainable approach utilizing tamarind seed polysaccharide (TSP). Polysaccharides are naturally occurring polymers derived from tamarind seeds, which function both as capping and reducing agents. Polyaniline (PANI) was subsequently capped over the as-prepared gold nanoparticles in order to facilitate the sensor property. The TSP-nAu-PANI film was fabricated by Methods I and II and utilized in the investigation of active sensor devices for the detection of organic pollutants such as benzene, toluene, and chloroform. The synthesized gold nanoparticles and the TSP-nAu-PANI films were analyzed using several analytical and spectral tools. Among the two methods, the Method II (TSP-nAu-PANI) film has a high sensing response toward benzene (105.69%), toluene (96.99%), and chloroform (74.98%). TSP is also a proton-conducting biopolymer, which enhances the conductivity of the material. The combination with the PANI layer of the film adsorbs the vapors easily and the prepared film material is more effective and ideal for sensing toxic gases.