Loading…
IIT Guwahati announced 'E-Eye' on 6 August 2026, a low-cost portable optical sensing device for detecting toxicants and cancer-causing heavy metals in water and biological samples.
The device was built at an approximate cost of ₹3,500, with a per-sample testing cost of around ₹2.
It works on the Beer-Lambert law, converting chemical colour intensity into digital readings.
Laboratory validation covered more than 2,700 samples and detected arsenic, lead, iron, chromium, fluoride and Escherichia coli.
The project was led by Prof. Tapas K. Mandal and Prof. Harshal B. Nemade of IIT Guwahati.
When a chemical reagent is added to a water sample, it produces a colour whose intensity depends on how much of the target contaminant is present. The Beer-Lambert law states that the absorption of light passing through a solution is proportional to the concentration of the absorbing substance and to the path length the light travels. E-Eye applies this by shining light through the treated sample, measuring how much is absorbed, and converting that measurement into a digital concentration reading. This is the same principle used by laboratory spectrophotometers — the achievement is reproducing it in a device costing about ₹3,500 that can be carried to the water source.
Simple Analogy: Hold two glasses of tea to the light — the darker one has more tea in it. The Beer-Lambert law turns that intuition into a precise measurement.
GS Paper 3 > Science and Technology — indigenous technology development; Environment — water pollution
General Awareness > Science and technology in news
General Awareness > Science and technology
A spectrophotometric principle stating that light absorption is proportional to the concentration of the absorbing substance and the path length.
A bacterium whose presence in water indicates faecal contamination.
A condition caused by excessive fluoride intake, affecting teeth and bones, prevalent in several Indian states.
Measurement of a substance's properties by how it interacts with light, as opposed to chemical or electrical methods.