Scientists at the Centre for Nano and Soft Matter Sciences (CeNS), Bengaluru, an autonomous institution of the Department of Science and Technology, have developed an advanced ammonia sensing platform based on a hybrid vanadium oxide-vanadium sulfide (VO_(x)/VS₂) heterostructure. The sensor detects harmful ammonia gas at extremely low concentrations of 319 parts per billion (ppb) while operating at room temperature, eliminating the need for elevated temperatures or external activation sources common in conventional gas sensors.
The sensor was engineered through a controlled surface transformation process that creates abundant active sites for ammonia adsorption while enhancing charge transport within the sensing layer. This design enables rapid and highly selective detection of ammonia under ambient conditions, with excellent selectivity against other common gases, stable operation over repeated sensing cycles, and long-term reliability exceeding ten weeks. The device effectively performs across a broad concentration range.
The research team developed multiple practical prototypes including a portable threshold-triggered monitoring system that provides immediate alerts when ammonia concentrations exceed predefined safety levels. The device automatically classifies environmental conditions into safe, warning, and danger zones. Additionally, the team created a self-powered ammonia detection device by integrating the sensor with a flexible piezoelectric nanogenerator that harvests mechanical energy from human motions, enabling gas detection without external power sources.
Flexible and wearable versions were fabricated on polymer, paper, and textile substrates, maintaining sensing capability under bending, twisting, and folding conditions. Prototype smart bands, smart-home warning systems, and electronic textile platforms were developed to showcase applications in personal safety monitoring and intelligent environmental sensing. The technology addresses ammonia exposure risks in fertilizer production, refrigeration, chemical manufacturing, and agriculture industries, where accidental exposure can cause severe irritation to eyes, skin, and respiratory system.