A GOX/RGO-CS-Fc/AuNPs nanosensing membrane in a light-addressable potentiometric biosensor for glucose specific detection

Glucose (Glu) is an important source of energy and metabolic intermediate for animal and plant cells. In this study, a high-performance biosensor for specific detection of Glu was constructed by combining a light-addressable potentiometric biosensor (LAPS) and a specific sensitive unit. The specific sensitive unit was adopted a silicon-based capacitive structure, and the glucose oxidase/reduced graphene oxide -chitosan-ferrooxidase/gold nanoparticles (GOX/RGO-CS-Fc/AuNPs) was modified onto the silicon-based working electrode to construct an nanosensing membrane. The interaction between the specific sensitive unit and Glu resulted in the formation of a bilayer potential, and the field effect generated by the bilayer potential caused a change in the capacitance of the silicon structure, which resulted in a change in the photocurrent-voltage characteristics of the LAPS. Through the potential shift in the photocurrent-voltage characteristics, the LAPS was capable of detection the concentration of Glu. Under optimal conditions, the potential shift was linearly correlated with the Glu concentration from 0.01 mg/mL to 4.00 mg/mL with R 2 of 0.9821, and the limited detection was 0.001 mg/mL. In addition, the LAPS showed good recovery (97.92 %–105.72 %), admirable specificity and stability in detection Glu in human serum samples.