Fluorosis

Scientists from the Institute of Nano Science and Technology (INST) have developed an equipment-free fluoride ion detection and quantification in drinking water with the naked-eye.
Fluorosis is a crippling disease resulting from deposition of fluorides in the hard and soft tissues of body due to excess intake of fluoride through drinking water/food products/industrial pollutants over a long period.
It results in dental fluorosis, skeletal fluorosis, and non-skeletal fluorosis.
According to WHO, the fluoride concentration in drinking water should not exceed 1.5mg/l.
The technology involves a push-pull chromophore based on 2, 3-disubstituted 1, 1, 4, 4-tetracyano-1, 3-butadienes (TCBDs) that changes colour upon exposure to fluoride ion.