Strategies for Embedding Electrochemical Sensors and Enzymatic Biofuel Cells into Miniaturized Platforms

Abstract

Miniaturized bioelectronics have great potential in smart devices and on-body biomedical applications, but their development is hindered by the limited availability of a sustainable energy supply. Enzymatic biofuel cells show promise as a power source, but integrating them into practical platforms presents challenges. To address this, we explore a range of materials and strategies for embedding energy-harvesting devices into flexible platforms. For instance, we present a self-powered bioelectronics mask that includes a biofuel cell, a supercapacitor, and a biosensor for detecting glucose levels, all powered by carbon nanotube-based printed biofuel cells. We have also engineered functional materials and customized inks for flexible, single-enzyme-based energy harvesting and self-powered biosensing devices. Additionally, we introduce a battery-free biosensing system that monitors metabolites through in vivo analysis. A self-powered glucose biofuel cell/biosensor integrated into a small circuit performs energy harvesting, biosensing, and wireless human-body communication, allowing for direct biochemical analysis of metabolic profiles. Furthermore, we developed a lab-in-a-mouth sensing device that analyzes thiocyanate levels directly and noninvasively. Carbon electrodes were screen-printed and integrated with mouthguards, and the resulting sensor demonstrates high sensitivity and selectivity for detecting salivary thiocyanate ions. We also discuss the challenges and opportunities in the fields of biosensors and on-demand sensors to further advance these technologies. It is envisioned that developments in biosensors and bioelectronics have significant potential in modern healthcare, including presymptomatic, preventive, and administrational medicine.