Guwahati: Researchers at the Indian Institute of Technology (IIT) Guwahati have developed a low-cost optical sensing device capable of rapidly detecting cancer-causing heavy metals, harmful bacteria and other toxicants in water and biological samples, a development that could significantly strengthen water quality monitoring across India.
Named ‘E-Eye’, the portable point-of-care testing device has been developed in line with the Government of India’s Jal Jeevan Mission, which aims to provide safe drinking water to every household. The device enables on-site detection of multiple toxicants with high accuracy and wirelessly transmits the collected data to water treatment facilities.
According to IIT Guwahati, the device has successfully detected arsenic, lead, iron, chromium, fluoride and Escherichia coli (E. coli) bacteria during laboratory tests. Researchers said its performance is comparable to conventional laboratory instruments such as UV-Visible and Atomic Absorption Spectrophotometers (AAS), while offering the advantage of field deployment and digital integration.
The findings have been published in the IEEE Sensors Journal in a paper co-authored by Prof. Tapas K. Mandal and Prof. Harshal B. Nemade, along with researchers from IIT Guwahati, KIIT Bhubaneswar and Ramakrishna Mission Residential College, Kolkata.
The device works by producing a coloured compound through a chemical reaction, with the intensity of the colour indicating the concentration of toxicants. It then uses optical sensing principles to convert the readings into digital data, displaying the concentration of contaminants in the sample.
“The device operates on the Beer-Lambert law and 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,” said Prof. Mandal of the Department of Chemical Engineering.
The researchers said the device has been developed at a cost of around Rs. 3,500, while the cost of testing each sample is approximately Rs. 2. They added that production costs could decline further with large-scale manufacturing.
Beyond water quality monitoring, E-Eye can also analyse toxicants in environmental and biological samples, including vegetables, food products, tea and herbal products, soil and milk. The research team has tested more than 2,700 samples using the device and reported accurate results.
Prof. Harshal B. Nemade of the Department of Electronics and Electrical Engineering said the technology has significant potential for use by government agencies, industries and private enterprises. He said it could support the Ministry of Jal Shakti in monitoring drinking water quality, help food and herbal product manufacturers maintain quality standards, and enable industries to monitor liquid effluents for heavy metals, bacteria and odour-causing compounds.
The project was supported by a research grant from the Ministry of Electronics and Information Technology (MeitY). To commercialise the technology, the research team has established a startup, ENVIONIX Labs Pvt. Ltd., and plans to collaborate with industry partners for technology transfer.
The researchers are now working on integrating solar panels into the device to make it self-sustaining and enable cloud connectivity for remote monitoring and data management.
IIT Guwahati said the innovation represents a significant step towards developing affordable, indigenous and smart sensing technologies for environmental monitoring, public health, industrial compliance and sustainable resource management in India.
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