Paper-based electrochemical (bio)sensors as advanced and sustainable wearable devices

Wearable electrochemical (bio)sensors have emerged over the last few decades as versatile analytical platforms for decentralized healthcare. Cellulose-based substrates are characterized by intrinsic properties, including porosity, capillarity, foldability, breathability, and mechanical robustness, which can be exploited to enable advanced wearable devices. This review critically examines how the features of the paper have enabled reagent-free designs, origami-inspired architectures, humidity-driven activation mechanisms, and modular strategies for electronic integration in advanced wearable electrochemical devices. Furthermore, it surveys recent applications in sweat and breath analysis, wound monitoring, plant diagnostics, and environmental surveillance, highlighting the key role of paper-based wearable electrochemical (bio)sensors as a future direction for the development of smart and sustainable wearable analysis.