Utilization of self-powered electrochemical systems: Metallic nanoparticle synthesis and lactate detection

Since the introduction of the first expounded triboelectric nanogenerator (TENG) in 2012, the theoretical and practical aspects of the TENG have been researched as an alternative energy harvesting technology to convert mechanical energy into electricity efficiently. Numerous self-powered sensing systems have adopted the TENG as a power source to further explore its versatile applications toward different targets. In this study, we employed a TENG to replace a traditional power supply for synthesizing different metallic nanoparticles using an electrochemical approach. Carbon fibers were adopted as the conductive substrates to grow the metallic nanoparticles, where the size and density of the nanoparticles on carbon fibers can be controlled by the electric output of the TENG. Additionally, we demonstrated that the as-prepared carbon modified and integrated with the TENG to construct a wearable self-powered sensing system exhibited significant selectivity and sensitivity toward lactate detection. Furthermore, the design of the sensing unit was favorable regarding its adaptability and flexibility to fit human body shapes and postures. As demonstrated in this study, the as-prepared self-powered sensing system could detect the lactate concentration in human perspiration, which can be an ideal wearable device for end users who seek real-time monitoring of their physical condition. This study concludes with a proposal for noninvasive biosensors, which provide boundless potential for future cross-field applications.