A Camera Phone-Based UV-Dosimeter for Monitoring the Solar Disinfection (SODIS) of Water

In this letter, we report on the development of a novel camera phone-based UV-dosimeter for monitoring the solar disinfection (SODIS) of water. The dosimeter consists of a UV indicator, methylene blue, dispersed in an ethylcellulose-based polymer matrix. To provide quantitative measurement of UV dose, we demonstrate the use of a camera phone to analyze dosimeter color change in response to UV exposure. The dosimeter response exhibits excellent agreement with a polynomial model (R²) >; 0.99) over the UV exposure range tested. A notable advantage of the dosimeter described here is that it can be deposited on a variety of substrates with the potential to be incorporated into water containers. It is envisaged that use of such a dosimeter in conjunction with mobile phone technology will enhance the use of SODIS thereby impacting significantly on the challenge of providing clean drinking water in developing regions of the world.