Novel synthesis of super peroxidase mimetic polycrystalline mixed metal hexacyanoferrates nanoparticles dispersion

Abstract

Mixed metal-hexacyanoferrates (MHCF) have shown promising applications for technological development particularly in energy storage technologies, ferromagnetic materials, and electrode materials. However, the challenge of controlling their chemical synthesis, solubility, polycrystallinity and nanogeometry have restricted the practical implementation of MHCF in commercial designs. Further, MHCFs have shown potential as peroxidase mimetics. There is still challenging demand to enhance the catalytic efficiency of such materials to the equivalent of biocatalytic activity thereby allowing the precise control of the mimetic character and ultimately leading to the development of new materials as powerful peroxidases i.e. Horseradish peroxidase (HRP) replacement during enzyme and immuno-sensors development. We report herein a new process that allows the controlled synthesis of biocompatible mixed MHCF nanoparticles with a variety of transition metal ions. The resulting polycrystalline mixed MHCF shows enhanced catalytic efficiency to hydrogen peroxide (H₂O₂) as compared to that of polycrystalline Prussian blue (PB) made under similar conditions with significant increase in catalytic efficiency as a function of respective hetero-transition metal ion of mixed FeHCF in the order of FeHCF < Mn–FeHCF < Ni–FeHCF < Cu–FeHCF justifying as perfect peroxidase replacement.