A review of sensing technologies for arsenic detection in drinking water

Water is essential resource vital for economic prosperity, well-being of ecosystems worldwide. Presence of arsenic, even in low concentrations, poses persistent threat due to its high toxicity, stability, its capacity to accumulate within food chains, affecting human health. To combat this issue, detection methods are striving to achieve lower limit of detection than World Health Organization standard of 10 parts per billion (133.3 nM), particularly focusing on toxic form, As3+. Various techniques have been developed to detect, quantify arsenic in drinking water, including spectroscopic and electrochemical methods. Spectroscopic methods offer high sensitivity and selectivity but can be complex, costly to operate, while electrochemical methods, although simpler, cost-effective, may sacrifice some sensitivity, selectivity. Recent years have witnessed emergence of portable, field-deployable arsenic sensing devices, primarily based on electrochemical or optical principles, with potential to transform arsenic contamination monitoring. This review explores recent advancements in arsenic detection techniques in drinking water, highlighting substantial progress in development of highly sensitive and selective methods. It covers range of sensor technologies, such as electrochemical sensors, optical sensors, and nanomaterial-based sensors, all of which offer improved detection limits, accuracy. It discusses integration of emerging technologies like machine learning and miniaturized devices for real-time arsenic monitoring in water sources. Practicality and cost-effectiveness of these techniques are evaluated, emphasizing need for robust, field-deployable sensors to ensure access to safe drinking water in both developed and developing regions. This review aims to contribute to ongoing efforts to mitigate the arsenic contamination crisis and protect public health.