3D Printed Bioelectrodes for Enzymatic Biofuel Cell: Simple, Rapid, Optimized and Enhanced Approach

Research to develop sustainable, automated and robust Enzymatic Biofuel Cell (EBFC) with high-energy output is hugely driven from its multiple application domains. To this end, continuous work to realize inexpensive and mass-manufacturable bioelectrodes has remained one of the prime challenges. In the present work, such bioelectrodes (both bioanode and biocathode) have been created by leveraging customized and novel 3D printed (3DP) composite Graphene/PLA filaments. The unsophisticated method is cost-effective and rapid, eradicates the requirement of any further amendment and post-processing treatment, and is amenable to print the end product within a short duration. To enhance the surface area and optimize the electrochemical sensing, the fabricated 3DP Graphene/PLA electrodes were treated with dimethylformamide (DMF) solution followed by the immobilization of GOx and laccase enzymes to realize bioanode and biocathode respectively. The morphological and elemental composition study of 3DP, 3DP/DMF treated and enzyme modified electrodes was carried out via scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) respectively. The electrochemical and polarization performances of the prepared bioelectrodes were evaluated using the linear sweep voltammetry (LSV), cyclic voltammetry (CV), and open circuit potential (OCP). Maximum current density of 1.41 mA/cm² at 0.5 V for bioanode at 40 mM glucose concentration, and 0.216 mA/cm² at 0.42 V was noticed for biocathode. To provide proof-of-concept, the fabricated bioelectrodes were assembled in a fluidic cell and the polarization performance was studied. Overall, the fabricated 3DP bioelectrode exhibited good stability with reasonably good retention of biocatalytic activity. The fabricated 3DP Composite Graphene/PLA electrodes are promising bioelectrodes material for EBFC and many electrochemical based biochemical sensing applications at the microfluidic level.