Implementation of electrochemical sensors in arsenic-contaminated areas of West Bengal in India toward rapid and point-of-use detection of arsenic in drinking water

Abstract

The difficulty of detecting small quantities of arsenic in water currently threatens the health of millions of people worldwide, as long-term exposure to arsenic has been associated with both cancerous and noncancerous health risks. Existing technologies make it possible to very accurately quantify arsenic levels in water; however the expense, extensive training, and off-site analysis required by these methods impede wide scale-use. Electrochemical detection offers many advantages, such as portability, minimal use of instrumentation, and ready integration with electronics. Toward a solution to water quality interventions, we have demonstrated an affordable and point-of-use platform capable of detecting trace amounts of arsenic in groundwater samples. Our electrochemical sensor utilizes a three-electrode system with carbon, silver, and silver/silver electrodes integrated with a handheld electrochemical analyzer. We employed our sensor to investigate arsenic concentration in drinking water on-site in the arsenic affected areas of the North 24 Parganas district in West Bengal, India. 38 samples were collected from shallow, midrange, and deep wells. A small water sample from each well was applied to the electrodes and the current response was quickly captured, returning quantitative results to the user, which alleviates the lag times and imprecise colorimetric assays that encumber current arsenic detection systems.