A selective novel non-enzyme glucose amperometric biosensor based on lectin–sugar binding on thionine modified electrode

Abstract

A novel non-enzyme glucose amperometric biosensor was fabricated based on biospecific binding affinity of concanavalin A (Con A) for d-glucose on thionine (TH) modified electrode. TH can be covalently immobilized on potentiostatically activated glassy carbon electrode through Schiff-base reaction. Subsequently, the surface-adherent polydopamine film formed by self-polymerization of dopamine attached to TH and afforded binding sites for the subsequent immobilization of Con A molecules via Michael addition and/or Schiff-base reaction with high stability. Thus, a sensing platform for specific detection towards d-glucose was established. The binding of Con A towards d-glucose can be monitored through the decrease of the electrode response of the TH moiety. Due to the high affinity of Con A for d-glucose and high stability of the resulting sensing platform, the fabricated biosensor exhibited high selectivity, good sensitivity, and wide linear range from 1.0 × 10 −6 to 1.0 × 10 −4 M with a low detection limit of 7.5 × 10 −7 M towards d-glucose.