Indian Scientists Develop Portable Sensor To Detect Toxic Ammonia Leaks Before They Turn Deadly

As India expands its fertiliser production, cold storage infrastructure, chemical manufacturing and intensive agriculture, the risk of accidental ammonia exposure is emerging as a significant occupational and public health concern.

Scientists at the Centre for Nano and Soft Matter Sciences (CeNS), Bengaluru, an autonomous institute under the Department of Science and Technology (DST), have now developed an ultra-sensitive ammonia sensor that can detect toxic gas leaks at extremely low concentrations, potentially enabling workers and nearby communities to receive early warnings before exposure reaches hazardous levels.

The innovation comes in the background of the recent chemical leak at a private seafood processing and export unit in the Kannigaipair–Manjungarai area near Periyapalayam in Tamil Nadu's Tiruvallur district on June 21, 2026 which left over 80 people injured and claimed around nine lives, highlighting the urgent need for robust leak detection and early warning systems at industrial facilities.

The study is published in the journal ACS Sensors.

The research team, led by Prof. S. Angappane, developed the sensor using a hybrid vanadium oxide-vanadium sulphide (VOx/VS₂) heterostructure. It can detect ammonia concentrations as low as 319 parts per billion (ppb) while operating at room temperature.

The material was engineered through a controlled surface transformation process that creates numerous active sites capable of rapidly adsorbing ammonia molecules while simultaneously improving electrical charge transport.

This combination significantly enhances the sensor's ability to detect ammonia rapidly and selectively, even under normal ambient conditions.

Unlike many commercially available gas sensors that require high operating temperatures or external heating elements, the newly developed device functions efficiently at room temperature. Researchers say this substantially reduces energy consumption while making the sensor suitable for continuous monitoring in workplaces.

Besides detecting ammonia at ultralow concentrations, the device demonstrated high selectivity by distinguishing ammonia from other commonly occurring gases, thereby reducing false alarms. It also maintained stable performance over repeated testing cycles and continued functioning reliably for more than ten weeks.

The researchers believe these characteristics make the technology particularly suitable for deployment across India's industrial ecosystem, where continuous gas monitoring often remains limited due to cost, maintenance requirements and power constraints.

Moving beyond laboratory research, the team translated the technology into practical prototypes designed for real-world use.

One of the prototypes is a portable threshold-triggered monitoring system capable of issuing immediate alerts whenever ammonia concentrations exceed predefined safety limits. The device automatically categorises exposure levels into safe, warning and danger zones, allowing workers and supervisors to quickly assess the situation without specialised technical training.

Such systems could be installed in fertiliser factories, cold storage facilities, warehouses, chemical manufacturing plants, research laboratories and agricultural settings where ammonia leakage remains a recognised occupational hazard.

In another significant advance, the researchers integrated the sensing platform with a flexible piezoelectric nanogenerator to create a self-powered ammonia detector. Instead of relying on batteries or external electricity, the device harvests mechanical energy generated through routine human movement and converts it into electrical power sufficient to operate the sensor.

This innovation could prove particularly valuable in remote industrial locations, warehouses, rural agricultural settings and disaster-prone areas where uninterrupted power supply cannot always be guaranteed.

The team also developed flexible versions of the sensor on polymer films, paper and textile materials. These wearable devices retained their sensing performance even after repeated bending, folding and twisting, demonstrating their suitability for smart wearable technologies, according to the study.

Prototype applications include wristbands capable of continuously monitoring ammonia exposure among industrial workers, electronic textiles that can be integrated into protective clothing, and smart home warning systems capable of detecting accidental gas leaks.

Such wearable technologies may offer an additional layer of protection for workers employed in high-risk occupations by providing continuous personal exposure monitoring rather than relying solely on stationary detectors installed within industrial premises, noted the researchers.

Public health experts also pointed out that rapid identification of leaks enables prompt evacuation, faster emergency response and timely use of protective equipment, thereby reducing the risk of mass exposure.