Carbon nanorods assembled coral-like hierarchical meso-macroporous carbon as sustainable materials for efficient biosensing and biofuel cell.

Sustainable conversion of renewable biomass into high-performance electrode materials has attracted extensive scientific and technological attention. However, to our knowledge, the potential of biomass derived carbon in biosensors and biofuel cells (BFCs) developments remains to be explored. Herein, the carbon nanorods assembled coral-like hierarchical meso-macroporous carbon (CN-CHMC) was synthesized as a sustainable electrode material to construct biosensor and lactate/air BFC. The CN-CHMC from cucumber (Cucumis sativus) possesses porous structure and plentiful defects, which not only facilitate the effective immobilization of enzymes but also accelerate electron transfer on the bioelectrode surfaces. As an electrochemical lactate biosensor, the CN-CHMC-based biosensor exhibits a wider linear range with lower detection limit (3.6 μM) and higher sensitivities (57.18 and 30.99 μA mM-1 cm-2) compared to carbon nanotube (CNT)-based biosensor. The feasibility of CN-CHMC-based biosensor in practical analysis is demonstrated by detecting lactate contents in real samples. By coupling with bilirubin oxidase-based biocathode, the lactate/air BFC equipped with CN-CHMC reveals a higher output power (112.7 μW cm-2) than that of CNT-based BFC. More interestingly, the lactate/air BFC demonstrates the ability to harvest energy from multi-component samples. The application of CN-CHMC may provide a new avenue to synthesize electrode materials with economical cost and excellent electrochemical activity.