Emergence of Electroanalytical Techniques for Arsenic Detection in Water: Recent Trends and Future Perspectives

Arsenic contamination in drinking water remains a critical global health concern, with inorganic arsenic species like arsenite (As(III)) and arsenate (As(V)) posing severe toxicity risks, including carcinogenic and systemic health effects. Recognized as a Group 1 carcinogen by the International Agency for Research on Cancer, arsenic necessitates stringent monitoring to comply with the World Health Organization's (WHO) permissible limit of 10 ppb. Traditional analytical methods such as atomic absorption spectroscopy (AAS) and inductively coupled plasma-mass spectrometry (ICP-MS) provide high precision but are constrained by high costs, operational complexity, and lack of portability, thereby limiting their accessibility in resource-constrained and out-of-laboratory settings. Previous work by the authors explored the methods of arsenic detection and determination by covering most of the analytical methods and techniques, including various sensors and biosensor advancements. This review delves into the progress made predominantly over the last two decades in electroanalytical detection methodologies, which have gained momentum due to their rapid response time, high sensitivity, and adaptability for portable and cost-effective sensing platforms. Unlike most of the material-focused articles, this review presents recent advances in arsenic detection using various electroanalytical techniques—stripping voltammetry, pulse voltammetry, sweep voltammetry, combined voltammetry approaches, amperometry, and electrochemical impedance spectroscopy. The review covers necessary fundamentals of electroanalytical techniques, recent advancements, and emerging trends in arsenic sensor development. The review further explores the portable and onsite electrochemical arsenic sensors, followed by the main challenges and future outlook in this space. The integration of nanomaterials, screen-printed electrodes, and microfluidic devices has significantly improved the detection capabilities. However, standardization, reliability, scalability, speciation, and seamless data integration remain pressing challenges. Smartphone-integrated electrochemical sensors and AI-driven data analytics have the capabilities to foster real-time and onsite arsenic detection with enhanced performance. By leveraging sustainable materials innovations, miniaturized electrochemical platforms, and smart data handling approaches, next-generation arsenic sensors hold promise for ensuring safe drinking water in vulnerable and remote communities worldwide.