Paper-Based Membraneless Co-Laminar Microfluidic Glucose Biofuel Cell With MWCNT-Fed Bucky Paper Bioelectrodes

This paper establishes a membraneless, co-laminar flow-based approach to develop a cost-effective microfluidic paper-based analytical device for enzymatic biofuel cell (
$\mu $
PAD-EBFC). The developed
$\mu $
PAD-EBFC supporting the self-capillary fluid transport action consists of Y-shaped paper microchannel with the fuel (glucose) and oxidant (O
₂
) streaming in parallel over carbon nanotube-based bucky paper electrodes modified with biocompatible electrocatalytic enzymes, such as glucose oxidase and laccase without any additional redox cofactor. The electrochemical performance for the modified bioelectrodes, i.e., electrocatalytic oxidation and reduction reaction, was carried out using linear sweep voltammetry, cyclic voltammetry, and open circuit potential. The overall performance of
$\mu $
PAD-EBFC was evaluated using the polarization studies. Subsequently, the catalytic activity of enzymes on the electrode surface was validated by the scanning electron microscope. This simple and portable
$\mu $
PAD-EBFC can generate the maximum power density to the order of
$100~\mu \text{W}$
/cm
²
(
$600~\mu \text{A}$
/cm
²
) at 0.505 V over prolonged durations of around 50 h. Hence, the presented
$\mu $
PAD-EBFC shows good power density and stability, leading to its strong potential to power miniaturized microelectronics devices and sensors.