In a breakthrough that could significantly improve air quality monitoring, scientists at the Centre for Nano and Soft Matter Sciences (CeNS), Bengaluru, have developed a portable, low-cost sensor capable of detecting toxic sulfur dioxide (SO₂) gas at extremely low concentrations. The innovation promises safer environments in both industrial and urban settings where exposure to harmful gases is a growing concern.
Sulfur dioxide, a pollutant commonly emitted from vehicle exhausts and industrial processes, poses serious health risks even in minute quantities. Known to trigger respiratory irritation, asthma attacks, and long-term lung damage, SO₂ is difficult to detect before it begins to impact health. Current monitoring systems are often costly, bulky, or lack the sensitivity required to identify the gas at trace levels.
To address these challenges, researchers at CeNS — an autonomous institute under the Department of Science and Technology (DST) — have designed a compact sensor by combining two metal oxides: nickel oxide (NiO) and neodymium nickelate (NdNiO₃). In this setup, NiO functions as the receptor that detects the gas, while NdNiO₃ acts as the transducer, amplifying the signal. This synergy enables the sensor to detect SO₂ concentrations as low as 320 parts per billion (ppb), far exceeding the sensitivity of many commercially available sensors.
Led by Dr. S. Angappane, the research team has also developed a portable prototype device that incorporates the sensor and offers real-time air quality feedback. The device includes a color-coded alert system to indicate exposure levels: green for safe, yellow for warning, and red for danger. Its intuitive design makes it user-friendly, even for individuals without technical training.
Designed to be compact and lightweight, the sensor system is ideal for deployment in industrial zones, densely populated urban areas, and enclosed spaces where continuous air quality monitoring is essential. The technology offers a practical and accessible solution for early detection and response to SO₂ pollution, ultimately supporting public health and environmental protection efforts.
