Room-Temperature Sensor for Early Ammonia Leak Detection Developed

Ammonia is widely used in fertilizer manufacturing, refrigeration, agriculture and chemical industries, but exposure to the gas can cause irritation to the eyes, skin and respiratory system.

Scientists at the Centre for Nano and Soft Matter Sciences (CeNS), Bengaluru, have developed a highly sensitive ammonia sensor capable of detecting extremely low concentrations of the gas while operating at room temperature. The new technology could improve safety in industrial workplaces, laboratories, agricultural facilities and other environments where ammonia leaks pose serious health risks. The research, supported by the Department of Science and Technology (DST), also includes portable, wearable and self-powered prototypes that demonstrate the technology's potential for everyday use.

New nanomaterial boosts sensitivity and cuts energy use

Ammonia is widely used in fertilizer manufacturing, refrigeration, agriculture and chemical industries, but exposure to the gas can cause irritation to the eyes, skin and respiratory system. Prolonged exposure may also lead to severe health complications, making continuous monitoring essential.

To improve gas detection, researchers designed a sensor using a hybrid vanadium oxide-vanadium sulfide (VOx/VS₂) heterostructure. The material was engineered through a controlled surface transformation process that increases the number of active sites available for ammonia adsorption while improving the movement of electrical charge within the sensing layer.

This combination allows the sensor to detect ammonia concentrations as low as 319 parts per billion (ppb), well below occupational safety limits. The device also demonstrated strong selectivity by distinguishing ammonia from other gases, maintained stable performance through repeated testing and remained reliable for more than 10 weeks.

Unlike many conventional ammonia sensors that require heating or external activation, the new device functions efficiently at room temperature, reducing energy consumption and making it easier to deploy in practical settings.

Portable and self-powered devices expand real-world applications

The research team, led by Prof. Angappane Subramanian with Dr. Vishnu G. Nath, Ankur Verma, Abhijit Paul and Dr. Subash Cherumannil Karumuthil, translated the laboratory technology into practical monitoring systems. One prototype is a portable threshold-based device that automatically alerts users when ammonia levels exceed preset safety limits. The system classifies conditions into safe, warning and danger zones, allowing workers and facility managers to respond quickly without requiring technical expertise.

The researchers also developed a self-powered ammonia detector by combining the sensor with a flexible piezoelectric nanogenerator. The device generates electricity from simple human movements, removing the need for an external power source and making it suitable for continuous monitoring in remote or resource-constrained locations.

Wearable sensors could improve personal safety

The team also produced flexible versions of the sensor on polymer, paper and textile substrates. These lightweight devices continued to function even when bent, twisted or folded, demonstrating their suitability for wearable electronics. To showcase future applications, the researchers created prototype smart bands, electronic textiles and smart-home warning systems capable of monitoring ammonia exposure in real time.

Published in the journal ACS Sensors, the study demonstrates how advanced nanomaterials and innovative device engineering can be combined to create practical solutions for environmental monitoring and workplace safety. The researchers believe the technology could support the next generation of portable, wearable and autonomous gas detection systems.