The present invention provides novel antimony doped tin oxide-polypyrrole nano-composites for in-situ and ex-situ ppm level ammonia gas sensing at very low temperatures (room temperature to sub-zero°C). During synthesis, hydrogen peroxide (H2O2) has been used as a novel template for simultaneous oxidative polymerization of pyrrole as well as the polymer loading on doped metal oxide base. Usability of the above composition was tested for ppm level in-situ and ex-situ ammonia gas sensing in a very low temperature range (room temperature to -30 °C). Stable and highly selective responses to ammonia gas were recorded in-situ and ex-situ at the very low temperature range (room temperature to -30 °C). The revelation of very low temperature ammonia sensing property by the antimony doped tin oxide-polypyrrole nano-composite could be used for detecting meat and meat product spoilage under in-situ and ex-situ refrigerated conditions for cold storages and commercial preservations.