3D Hybrid branched carbon/ZnO core-shell nanostructure as biosensor for sensitive and selective detection of glucose

Abstract

Reliable glucose monitoring at physiological pH and clinical practical range is critical for appropriate diabetes management which remains one of a major health concern. Herein, we describe the construction of flexible and 3D hybrid electrode for glucose sensing by successful immobilization of the GOx on branched carbon/ZnO core–shell nanostructures electrode. The microstructure, morphology and device properties of glucose sensor was systemically characterized by using HRTEM, SEM, FT-IR, and electrochemical analysis. The branched carbon/ZnO core–shell nanostructure sensor showed reliable stability, selectivity and remarkable sensitivity (i.e., 32.48 (±0.04) µA mM−1 cm−2) for glucose in clinical range at physiological pH conditions. The mediator less direct electron communication between the electrode surface and the redox center (FADH & FAD) was also analyzed comprehensively, which concludes an efficient direct electron communication (DET). This enhanced DET can be attributed to the larger surface area provided by the branched carbon/ZnO core–shell nanostructure and also favorable orientation of GOx which allows close proximity of the redox center and the electrode surface. It is believed that such kind of sensors could provide an ideal platform for continuous glucose monitoring (CGM) device fabrication which could perform glucose sensing in real-time and in-vivo analysis.