IIT Guwahati's optical sensing device may turn water quality monitoring easy through optical sensing point-of-care device

Indian Institute of Technology Guwahati researchers have developed an optical sensing device that can instantly detect a variety of toxicants in water and other biological samples. The innovation could address the key challenge of ensuring safe drinking water under the government’s flagship drinking water supply programme Jal Jeevan Mission. While the mission aims to provide tap water to every household, maintaining water quality remains a challenge due to different water sources, which may contain heavy metals and other disease-causing bacteria.

"The device combines optical sensing with digital electronics to generate accurate quantitative measurements. Our device has been able to successfully detect toxicants such as arsenic, lead, iron, chromium, fluoride, and Escherichia coli bacteria", Tapas K. Mandal, Professor, Department of Chemical Engineering, IIT Guwahati, said.

To address the challenge of water quality monitoring, the research team has developed a portable point-of-care testing device named E-Eye. Working as an electronic eye, it detects multiple toxicants on-site while maintaining high accuracy, and transmits the recorded data wirelessly to water treatment facilities.

E-eye works through a chemical reaction that produces a colored compound, in which color intensity highlights the concentration of the toxicants. Using basic optical principles, the device analyses the water and converts the sensor's output into digital data and displays the toxicant concentration.

Contrary to conventional laboratory based costly instruments, E-Eye is suitable for direct field deployment, where it can detect water toxicants right at the water source. During laboratory tests, the research team found that results shown by E-Eye are comparable to those of standard UV-Visible and Atomic Absorption spectrophotometers (AAS), while offering advanced digital integration functionality.

Other than water quality monitoring, the device is capable of analysing toxicants in environmental samples, biological samples, vegetables, food products, tea and herbal products, soil, and milk as well. The research team has tested more than 2700 samples with the developed device and recorded accurate results.

"E-Eye has prominent application potential across government departments, industries, and private enterprises. It can support agencies under the Ministry of Jal Shakti in water quality monitoring, assist food and herbal product manufacturers, and help industries monitor liquid effluents containing heavy metals, bacteria, and odor-causing compounds", Harshal B. Nemade, Professor, Department of Electronics and Electrical Engineering, IIT Guwahati, said.

Supported by a research grant from the Ministry of Electronics and Information Technology (MeitY), the research team has established a startup, ENVIONIX Labs Pvt. Ltd., to commercialise the developed technology. Additionally, the team also plans to collaborate with an industry partner to initiate technology transfer and bring this innovation from lab to land.