Covalent immobilization of horseradish peroxidase onto magnetic nanoparticles

The biocatalyst horseradish peroxidase (HRP) was successfully immobilized onto magnetic nanoparticles by the glutaraldehyde method. The influence of pH medium, ionic strength, the initial protein concentration, temperature and the effect of the functional additive pentaethylenehexanamine on HRP immobilization were studied. The study consisted in seeking for the optimal conditions at which the binding efficiency and the activity of the immobilized horseradish peroxidise were the highest. The results showed that the highest immobilization yield, nearly 60 %, was attained at pH 4.0. It was found that the variation of ionic strength directly affected the HRP immobilization. The enzyme was immobilized at the optimal conditions with the final residual activity of 80 %. However, the enzyme attached onto functionalized magnetic support and additionally coimmobilized with the functional additive, showed better hydrogene peroxide tolerance than the immobilized enzyme without the pentaethylenehexanamine, respectively.Outgoin