Macroporous ordered silica foam for glucose oxidase immobilisation and direct electrochemical biosensing

Abstract

We have applied macroporous-ordered silica-foam (MOSF) for glucose oxidase (GOx) immobilisation and for glucose biosensing. Due to the favorable properties of MOSF, the immobilised GOx retained good bioactivity, resulting in good performance in direct electrochemistry and electrocatalysis. A glucose biosensor based on a poly(diallyldimethyl-ammonium chloride) (PDDA)/GOx–MOSF/modified glassy carbon electrode allowed the detection of glucose with high sensitivity (2.336 μA mM⁻¹ cm⁻²), a linear range from 50 to 1950 μM, and LOD (glucose) = 4.2 μM (S/N = 3). The biosensor displayed good sensitivity, stability, selectivity, and reproducibility of fabrication, making MOSF a promising material for construction of redox mediator-free enzyme biosensors based on direct electrochemistry of an immobilised enzyme.