Encapsulation of horseradish peroxidase into hydrogel, and its bioelectrochemistry

A biohybrid hydrogel is fabricated by integrating horseradish peroxidase (HRP) with polyhydroxyl cellulose (PHC), which is prepared by mixing of poly(vinyl alcohol) and carboxymethyl hydroxyethyl cellulose. PHC provides a biocompatible microenvironment for HRP, and the UV-vis spectrum indicates that the confromation of HRP-loaded biohydrogel is well retained relative to free HRP. Based on the direct electrochemistry and electrocatalytic ability of HRP, a third-generation H₂O₂ biosensor is developed. Under the optimized conditions, the H₂O₂ biosensor shows a linear response over the range from 1.0 μM to 1.0 mM with a detection limit (S/N=3) of 0.5 μM.