Development of low-cost plastic microfluidic sensors toward rapid and point-of-use detection of arsenic in drinking water for global health

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 in a microfluidic platform 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 microfluidic 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 chloride ink electrodes printed onto a disposable plastic substrate. A small water sample is applied to the electrodes and the current response is quickly captured, returning quantitative information to the user, which alleviates the lag times and imprecise colorimetric assays that encumber current arsenic detection systems.