A highly sensitive hybrid digital sensor for room temperature arsenic detection

Arsenic is a significant water pollutant that causes a severe threat to human health due to its high toxicity. Therefore, the development of sensitive digital point-of-care test (POCT) Kits is highly relevant in monitoring the quality of potable water and beverage. The present work has developed an indigenous green sensor kit for detecting arsenic in liquid samples like potable water, soft drinks, and fruit juices. In this test Kit, in-situ hydrogen generated by electrolysis, which converts arsenic into arsine gas and reacts with Au3+ on a paper strip. Due to the specific nature of the reaction, the paper strip acted as a paper sensor for arsenic by changing its color from light yellow to a wide range of gray-red. An App was developed for quantifying arsenic using the RGB values of the paper sensor response. The prototype successfully detected arsenic in spiked water and beverages and was in good agreement with the Atomic Absorption Spectrophotometer (AAS). It can detect arsenic concentrations ranging from 4 to 100 µg/L with a response time of 5 min for 4–30 µg/L and 3 min for 30–100 µg/L. The kit has advantages such as lower sensitivity, faster response time, reusability, user-friendliness, eco-friendliness, and green technology.