Magnetic labelled horseradish peroxidase-polymer nanoparticles: a recyclable nanobiocatalyst

In this study, the reusability and process stability of nano-reengineered horseradish peroxidase was investigated in a fluorescence-based sensing system for hydrogen peroxide determination as a model application. To this end, dendron macromolecules were attached to the enzyme surface through bio-conjugation techniques. The resulting enzyme-polymer nanoparticles, with an average size of 14(+/- 2) nm, showed significant life time and thermal stability. For enzyme recovery and reusability purposes, the enzyme-polymer nanoparticles were labelled with magnetic nanoparticles with a labelling yield of 90 %. These labelled enzyme molecules showed significant process stability, i.e., up to 7 recycling period in a model sensing system. A linear calibration curve was obtained over a hydrogen peroxide concentrations range from 5x10(-8) to 1x10(-5) mol L-1, with a detection limit of 1.3x10(-9) mol L-1 for the sensing system under the optimal conditions.