Buckypaper bioelectrodes: emerging materials for implantable and wearable biofuel cells

Carbon nanotubes (CNTs) have been widely exploited for the development of enzymatic biofuel cells with sufficient power densities in the W to mW range for operating low-power bioelectronic devices from renewable substrates. Buckypaper is a randomly oriented self-supporting film of carbon nanotubes, resembling an electronic paper, with excellent prospects for the construction of high performance enzymatic electrodes for use in biofuel cells. Attractive properties of buckypaper materials include large specific surface areas, high electrical conductivity, flexibility, biocompatibility, scalable production and the ability for efficient electron transfer with enzymes. Buckypapers are ideal self-supporting frameworks for enzymes and guest molecules such as metals, polymers and redox molecules, permitting the development of a wide range of catalytic bioelectrode interfaces. This review summarizes recent developments and advances of buckypaper bioelectrodes as an emerging component for body-integrated energy harvesting biodevices.