Stable immobilization of mediator in porous carbon material via capping technique for fabricating sensitive enzyme-based glucose sensor

A sensitive and stable porous carbon-modified enzyme sensor based on mediated electron transfer (MET) was developed for d-glucose detection. Toluidine blue (TB) was loaded as a mediator into the pores of porous carbon particles, and the pores were capped by flavin adenine dinucleotide-dependent glucose dehydrogenase (FAD-GDH) by one-step drop-casting of TB and FAD-GDH. TB was found to be stably capped in the pores by FAD-GDH for 21 d. The resulting sensor enabled the reproducible and sensitive detection of d-glucose with a detection limit of 6.5 µM. The present sensor is promising for the long-term monitoring of low concentrations of biomarkers.