Highly sensitive and selective electrochemical identification of d-glucose based on specific concanavalin A combined with gold nanoparticles signal amplification

A novel electrochemical assay for non-enzyme detection of glucose was proposed based on higher biospecific binding affinity of concanavalin A (Con A) for d-glucose over thiolated β-cyclodextrins (β-SH-CDs), coupled with gold nanoparticles (AuNPs) signal amplification. In this method, β-SH-CDs could bind to both Con A which was covalently immobilized on the pretreated glassy carbon electrode and AuNPs onto which thionine (TH) could be attached. However, upon the addition of Con A, the electrode response of the TH moiety decreased which was attributed to the glucose competing with β-SH-CDs at the binding sites of Con A. Consequently, a highly stable sensing platform was developed. The as-established strategy exhibits high selectivity and good sensitivity. A linear response to the d-glucose concentration ranging from 5.0 × 10−7 to 1.55 × 10−5 M and a low detection limit of 2.2 × 10−7 M are obtained. Furthermore, this new strategy can provide a new general platform for the non-enzyme determination of glucose.