Development of PEG-coated iron oxide nanoparticles for the oxidation of adrenaline

The present study reports the autoxidation of adrenaline to adrenochrome using polyethylene glycol coated iron oxide nanoparticles (PEG-IONPs) in hydrogen peroxide presence. The influence of PEG with different molecular weights has been studied for the oxidation of adrenaline. A slightly modified co-precipitation method was employed to synthesize PEG-IONPs that were characterized using TEM, XRD, FTIR, TGA, and VSM analyses. Oxidation rate of adrenaline was examined with bare-IONPs and PEG-IONPs using H2O2in aqueous and surfactant media. Cetyltrimethyl ammonium bromide (CTABr), sodium dodecyl sulphate (SDS), and Triton X-100 (TX100) were used at premicellar concentrations. The existence of PEG on the surface of IONPs decreased the rate of reaction. Also, the improvement in molecular weight of PEG further declined the reaction rate. The addition of surfactants increased the oxidation rate in the copresence of bare-IONPs, however, decreased the rate with increasing molecular weight of the polymer. Thus, higher molecular weight PEG-supported PEG-IONPs could be used to decrease the oxidation of adrenaline.