Multilayer structured carbon nanotubes/poly-l-lysine/laccase composite cathode for glucose/O2 biofuel cell

Multilayer film of laccase, poly-l-lysine (PLL) and multi-walled carbon nanotubes (MWNTs) were prepared by a layer-by-layer self-assembly technique. The results of the UV–vis spectroscopy and scanning electron microscopy studies demonstrated a uniform growth of the multilayer. The catalytic behavior of the modified electrode was investigated. The (MWNTs/PLL/laccase)n multilayer modified electrode catalyzed four-electron reduction of O2 to water, without any mediator. The possible application of the laccase-catalyzed O2 reduction at the (MWNTs/PLL/laccase)n multilayer modified ITO electrode was illustrated by constructing a glucose/O2 biofuel cell with the (MWNTs/thionine/AuNPs)8 GDH film modified ITO electrode as a bioanode and the (MWNTs/PLL/laccase)15 film modified ITO electrode as a biocathode. The open-circuit voltage reached to 700 mV, and the maximum power density achieved 329 μW cm−2 at 470 mV of the cell voltage.