Design and Construction of Magnetic Nanoparticles Incorporated with a Chitosan and Poly (vinyl) Alcohol Cryogel and its Application for Immobilization of Horseradish Peroxidase

Magnetic nanoparticles were synthesized by simple co-precipitation method in aqueous medium. The structural characteristics of the powders were studied by XRD and the sizes of nanoparticles were measured with dynamic light scattering. The prepared magnetic nanoparticles were about 43 nm in diameter and were then subsequently incorporated into a chitosan and poly (vinyl alcohol) cryogel and applied to immobilize the horseradish peroxidase through covalent binding method (MNP-CS-PVA-HRP cryogel microbar). The MNP-CS-PVA- HRP cryogel microbar was applied for the detection of hydrogen peroxide. The horseradish peroxidase can catalytically oxidize the substrate of hydrogen peroxide and o-dianisidine, generating blown colour that are proportional to the concentrations of hydrogen peroxide. The results showed that the absorption values at 430 nm increased with the hydrogen peroxide concentrations ranging from 10-1,000 mM. The immobilized horseradish peroxidase on magnetic nanoparticles retained enzyme activity up to the 10th reusable. The proposed approach confirmed that the magnetic nanoparticles not only possessed enzyme activity but also showed potential application in varieties of simple, robust, and cost-effective analytical methods in the future.