Polypyrrole (PPy)–Zn2SnO4 nanocomposites have been prepared using dodecylbenzene sulfonic acid as a dopant by chemical oxidative polymerization for different weight percentages of Zn2SnO4 nanoparticles (0–20 wt%). The physicochemical characterization confirmed well-formed DBSA doped PPy–Zn2SnO4 nanocomposites with globule—like morphology and high porosity. Moreover, the UV–Vis spectrum revealed a blue shift for nanocomposites with respect to pure PPy, reflecting the modified electronic states as a result of effective interaction between PPy and Zn2SnO4 nanoparticles. All of the synthesized nanocomposites had a good thermal stability below 200 °C (< 4% weight loss). We applied the synthesized nanocomposites as a resistive sensor to detect the ethanol vapor. The results demonstrate that PPy–Zn2SnO4 (10 wt%) nanocomposite has the highest DC conductivity and response at room temperature. Also, it shows a linear response, appropriate recovery time and reproducibility. The excellent long-term stability (about 30% less than the initial experiment) after 7 months is observed for the sensor based on PPy–Zn2SnO4 (10 wt%), which makes it convenient for practical applications.
