Fabrication of Enzymatic Glucose Hydrogel Biosensor Based on Hydrothermally Grown ZnO Nanoclusters

Glucose oxidase was immobilized using a poly (hydroxyethylmethacrylate)-based hydrogel composite material containing polyethylene glycol and cross-linked with tetraethyleneglycol diacrylate onto a ZnO-modified microdiamond biosensor. The ZnO-modified biosensor was grown by hydrothermal decomposition on array of gold patterned microdiamonds with an electroactive area of 18.8 mm². The morphology of the ZnO-modified electrode was characterized by scanning electron microscope. A potential of +0.7 V versus Ag/AgCl reference electrode was applied to the biosensor. The hydrogel composite ZnO-modified microdiamond biosensor exhibited a linear dynamic range from 0.01 to 15 mM and a reproducible sensitivity of 31.4 μA/mM cm². The experimental detection limit was 0.01 mM with a rapid response time of <;2 s.