Electrochemical Stripping Analysis at Paper-Based (Bio)Sensors: Current State-of-the-Art and Prospects

Paper-based devices (PADs) have gained increasing attention over the last few years as portable, low-cost and disposable (bio)sensors for point-of-care and on-site analysis. Electrochemistry is a particularly attractive detection mode in PAD assays thanks to its sensitivity and compatibility with portable instrumentation. In particular, electrochemical stripping analysis (ESA) is one of the most sensitive electroanalytical techniques, and, therefore, is suitable for trace assays required in environmental monitoring, clinical diagnostics and food control. Coupling paper as a functional platform with the exceptional sensitivity of ESA creates a powerful analytical tool for trace metals and (bio)sensing. This perspective briefly outlines the current state-of-the art in the field of paper-based (bio)sensors using ESA. It describes the principle of ESA, illustrates different strategies for on-paper electrode fabrication and modification and demonstrates representative applications to trace metal analysis and biosensing. Finally, limitations are identified and future prospects are discussed.