Development of biofuel cell adopting multiple poly(diallyldimethylammonium chloride) layers immobilized on carbon nanotube as powerful catalyst

A new enzymatic biofuel cell (EBC) adopting multiple glucose oxidase (GOx) and poly(diallyldimethylammonium chloride) (PDDA) immobilized on carbon nanotube (CNT) ([GOx/PDDA]_n/CNT) is fabricated and effects of [GOx/PDDA]_n/CNT catalysts on EBC performance are investigated using various electrochemical characterizations. Initially, both redox reaction of flavin adenine dinucleotides (FADs) within GOx and stepwise deposition of PDDA and GOx on CNT are estimated to determine optimal [GOx/PDDA]_n/CNT catalyst. Also, its electron transfer pathway and reaction mechanism related to oxygen mediator is elucidated. With the optimized [GOx/PDDA]₅/CNT catalyst, excellent catalytic activity and EBC performance are measured. When the catalyst is used, its electron transfer rate constant is 15.97 s⁻¹, glucose sensitivity is 17 μA mM⁻¹ cm⁻², Michaelis–Menten constant is 1.44 mM and EBC maximum power density (MPD) is 0.79 mW cm⁻². It indicates that the values are better than those of other similar structures. Moreover, in a comparison with MPDs of EBCs without provision of glucose, it is proved that PDDA and GOx make key role in improving EBC performance.