Electrochemical non-enzymatic glucose sensor using ionic liquid incorporated cobalt-based metal-organic framework

Abstract

Cobalt-based metal-organic framework (Co-MOF) and MOF-derived cobalt hydroxide (Co(OH)2) were successfully prepared by ionothermal and one-pot conversion methods, respectively. The introduction of ionic liquid in the synthesis of MOF could enhance electrical conductivity, thereby improving its electrocatalytic performance. The morphologies and structural compositions were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). Cyclic voltammetry (CV) and amperometry investigation showed that the Co-MOF displayed higher electrochemical sensing performance toward glucose as compared to the Co(OH)2. The Co-MOF modified electrode offered a wide linear range (from 5 μM to 900 μM) and a low detection limit of 1.6 μM (S/N = 3). The electrochemical glucose sensor also exhibited excellent stability, reproducibility and selectivity. The MOFs impregnated with ionic liquids probably are capable of overcoming the disadvantage of the traditional MOFs, and the effective electrochemical property of the ionic liquid incorporated Co-MOF for the sensing of glucose can provide a direction for the bioactive molecules determination.