Immobilization of soybean peroxidase on silica-coated magnetic particles: a magnetically recoverable biocatalyst for pollutant removal

Abstract

In this work we investigated the enzymatic degradation of ferulic acid, a model pollutant, by free and immobilized soybean peroxidase. With the aim of developing greener catalysts, we proposed the synthesis of a magnetic catalyst prepared via immobilization of soybean peroxidase onto a magnetic nanosupport by covalent attachment. The immobilization of soybean peroxidase was carried out using magnetite nanoparticles modified with amino groups as support. The magnetite particles were characterized before and after chemical modification by XRD, SEM and TEM analysis. The characterization data indicated that the Fe₃O₄–SiO₂ nanoparticles were successfully synthetized. The high immobilization yield was obtained in only 1 hour of reaction (89.23%). The resulting nanobiocatalyst (enzyme load 5.25 U) was able to remove 99.67 ± 0.10% of ferulic acid in comparison to 57.67 ± 0.27% for free enzyme under the same reaction conditions. The immobilized peroxidase could easily be separated under a magnetic field and reused. On the basis of these results, we concluded that the prepared magnetic nanoparticles can be considered a high-performance nanocatalyst for environmental remediation.