enzyme, magnetic nanoparticle, bioremediation, conjugates
Enzymes are proteins that function as biocatalysts in bioremediation. One of the major concerns in environmental applications of enzymes is their short lifetime. Enzymes lose their activity due to oxidation, which results in less stability and a shorter lifetime thereby rendering them less efficient. An effective way to increase the stability, longevity, and reusability of the enzymes is to attach them to magnetic iron nanoparticles. If enzymes are attached to the magnetic iron nanoparticles then we can easily separate the enzymes from reactants or products by applying a magnetic field. With this aim, two different catabolic enzymes, trypsin and peroxidase, were attached to uniform core-shell magnetic nanoparticles (MNP’s), produced in our laboratory. Our study indicates that the lifetime and activity of enzymes increases dramatically from a few hours to weeks and that MNP-Enzyme conjugates are more stable, efficient, and economical. We predict that MNPs shield the enzymes preventing them from becoming oxidized. This results in an increased lifetime of the enzymes. Because of the high magnetization (~140 emu/g) of our MNPs, nanoparticle-enzyme conjugates can efficiently be magnetically separated, making enzymes more productive. We also found that the enzyme structure plays a major role in efficient attachment of MNPs.