The assisting-approach of horseradish peroxidase immobilized onto amine-functionalized superparamagnetic iron oxide nanoparticles as a biocatalyst

Abstract

To enhance the removal of dye, horseradish peroxidase (HRP) was immobilized onto amine-functionalized superparamagnetic iron oxide and used as a biocatalyst for the oxidative degradation of Acid black-HC dye. The anchored enzyme was characterized by sets of techniques such as vibrating sample magnetometer, Fourier transform infrared, X-ray diffraction, thermogravimetric, scanning electron microscopy, BET and BJH methods, nitrogen adsorption-desorption measurements , Zeta potential, energy dispersive X-ray (EDX), and transmission electron microscopy. The Michaelis constant (K m ) values of free peroxidase and immobilized horseradish peroxidase were determined that equal 4.5 and 5 mM for hydrogen peroxide; 12.5 and 10 mM for guaiacol, respectively. Besides, the free peroxidase is thermally stable at 40°C however, the immobilized enzyme was up to 60°C. In the catalytic experiment, the immobilized HRP showed superior catalytic activity compared with free HRP for the oxidative decolorization and removal of Acid black-HC dye. The impacts of experimental parameters for instance catalyst dosage, pH, H 2 O 2 concentration, and temperature, were investigated. The reaction followed second-order kinetics and the thermodynamic activation parameters were determined.