Multifunctional Fiber for Synchronous Bio‐Sensing and Power Supply in Sweat Environment

Abstract Continuous monitoring of human sweat, which enables highly sensitive multiple biomarkers analysis with a portable power supply, is increasingly desired for the remote healthcare industry. Smart fibers with on‐demand functionality are ideal candidates for fabricating noninvasive and conformal bioelectronic devices owing to their considerable flexibility. Herein, a multifunctional textile patch based on a reduced graphene oxide (rGO)/tetra‐aniline (TANi) fiber for simultaneous biomarker monitoring and energy supply is reported. Benefiting from the multi‐electrochemical redox states and proton doping/dedoping characteristics of TANi, rGO/TANi hybrid fibers are combined into an energy storage device and biosensor in a physiological environment. GO flakes increase the viscoelasticity of the wet‐spinning dope by regulating the noncovalent interactions between TANi aggregates, thereby enhancing the mechanical strength and conductivity of the resulting rGO/TANi hybrid fiber. Consequently, the hybrid fiber exhibits high volumetric capacitance and versatile sensing capability for various physiological analytes, e.g., pH, K⁺, and glucose in sweat electrolyte. Furthermore, a wireless continuous sweat monitoring system is constructed by integrating the multifunctional fiber sensor into a printed electric circuit board with programmed functionality. Such a delicate integrated design that harnesses the signal collection and communication units is anticipated to facilitate practical applications in personalized diagnostic and physiological health.