Acrylic modification as an environmentally acceptable supporter for improving peroxidase enzyme: stability and reusability

Abstract

This study focuses on the immobilization of horseradish peroxidase (HRP) on modified acrylic fabrics incorporating gold and silver nanoparticles. The process involves treating the acrylic fabrics with hydroxylamine hydrochloride and then coating them with silver and gold nanoparticles. Both obtained materials, treated acrylic fabrics-coated with silver nanoparticles (AgNPs@TA-HAC) and treated acrylic fabrics-coated with gold nanoparticles (AuNPs@TA-HAC), were utilized as supporters for HRP. The physicochemical properties of modified acrylic fabrics were investigated using FTIR, SEM, and zeta potential. HRP immobilized on AgNPs@TA-HAC displayed an activity of 69 units/g support with a specific activity of 4.55 units/mg protein, whereas HRP immobilized on AuNPs@TA-HAC demonstrated an activity of 76 units/g support with a specific activity of 4.75 units/mg protein. After the 15 repetitive cycles, the immobilized HRP on AuNPs@TA-HAC and AgNPs@TA-HAC retained 75 and 59% of their enzymatic activity, respectively. The immobilized HRP on both material supporters retained its activity better compared to the free HRP when exposed to all tested organic solvents. The Michaelis constant (Km) for free HRP and HRP immobilized on AuNPs@TA-HAC and AgNPs@TA-HAC were determined to be 6.23, 8.65, and 9.11 mM, respectively. The maximum reaction rates (V max) for the immobilized HRP on both supports were slightly reduced at 0.71 and 0.69 U/mL, compared to 0.74 U/mL for free HRP. This approach of utilizing acrylic fabrics and metal nanoparticles provides a promising method for enzyme immobilization, with potential applications in various industries.