Self-powered triboelectric sensor with N-doped graphene quantum dots decorated polyaniline layer for non-invasive glucose monitoring in human sweat

A novel non-invasive wearable self-powered triboelectric sensor (TES) for simultaneous physiological monitoring had shed the light on its extraordinary performance, which become a promising choice for detecting glucose concentration from human sweat via non-invasive strategy. For realizing the function of wearable TES, the flexible substrate of conducting polymers commonly served as matrix for not only immobilizing the specific enzyme, but also played as the sensing layer by the coupling effect of triboelectrification/enzymatic reaction. To boost up the reliability and sensitivity of conducting polymer-based TES, in this study, a nanocomposite of Ndoped graphene quantum dots decorated polyaniline (NGQDs/PANI) is designed as a triboelectric layer for noninvasive glucose detection. The surface electronegativity of PANI was changed by decorating the NGQDs with electron-rich functional groups for increasing the surface charge, which further facilitating the charge transfer between the PANI and intermedia and then enhancing triboelectric outputs. Upon the enhanced electron transfer and surface charge by NGQDs, NGQDs/PANI/GOx based TES offers greater sensitivity (23.52 mM-1) in glucose detection compared to pristine PANI/GOx one (16.44 mM-1). Notably, this study demonstrates the feasibility of wearable TES on human skin and their reliable and sensitive performance with a self-driving system without any external power source.