Synergistic contributions of fullerene, ferrocene, chitosan and ionic liquid towards improved performance for a glucose sensor

Abstract

The paper describes an ingenious approach for the fabrication of a promising glucose sensor, GOx/C 60-Fc-CS-IL, that exploits the synergistic beneficial characteristics of fullerene (C 60), ferrocene (Fc), chitosan (CS) and ionic liquid (IL) for glucose oxidase (GOx). Cyclic voltammetry, impedance spectroscopy and chronoamperometry were used to evaluate performance of the biosensor, respectively. Since efficient electron transfer between GOx and the electrode was achieved, the biosensor exhibits a high sensitivity (234.67 nA nM −1 cm −2), low detection limit (S/N = 3) (3 × 10 −9 M), fast response time (0.752 s), wide calibration range (from 1 × 10 −8 M to 1 × 10 −5 M) and excellent long-term stability (30 weeks). The apparent Michaelis–Menten constant ( K M) of GOx on the composite medium, 0.03 mM, shows high bioelectrocatalytic activity of immobilized enzyme toward glucose oxidation. Due to low operating potential (100 mV), the biosensor is relatively insensitive to electroactive interfering species in human blood such as ascorbic acid, and uric acid, which are commonly found in blood samples. Excellent electrochemical reversibility, high sensitivity and stability, technically simple and possibility of preparation at short period of time are of great advantages of these glucose biosensors.