Flexible and optimized carbon paste electrodes for direct electron transfer-based glucose biofuel cell fed by various physiological fluids.

Development of bioelectrodes with multiple virtues, such as biocompatibility, flexibility, versatility and cost-effectiveness, remains a huge area of research for multiple applications. Here, we delve upon fabricating carbon electrodes using a desktop PCB printer in a cost-and-time efficient manner (less than 2 min). Such printed carbon paste electrodes have been incorporated to develop an enzyme-based glucose biofuel cell to power various low-power biomedical devices and for biosensing. The bioelectrodes were prepared by electrodepositing gold nanorods followed by the immobilization of suitable enzymes. These bioelectrodes were tested for their electrochemical behavior and was setup as a Direct Electron Transfer (DET)-based enzymatic biofuel to be amenable for various physiological fluids, like tears, human saliva, whole blood and blood serum, due to its biocompatibility and efficiency. It delivered maximum energy of 3.18 µW/cm² and 8.8 µW/cm² from tears and human serum, respectively. These fabricated electrodes have huge potential to be incorporated in miniaturized devices as a renewable energy source for implantable and self-powered bioelectronics. [ABSTRACT FROM AUTHOR]