Development of Co3[Co(CN)6]2/Fe3O4 Bifunctional Nanocomposite for Clinical Sensor Applications

In this study, a magnetically separable three-dimensional (3D) Co3[Co(CN)6]2/Fe3O4 nanocomposite comprising magnetic nanoparticles (NPs) adsorbed on the nanocubes of a cobalt Prussian blue analogue was prepared. The nanocomposite exhibited enhanced electrochemical performance in Co2+/Co3+ conversion, while the superparamagnetic behavior of the magnetite NPs was preserved even after adsorption on the nanocubes. Increased Faradaic currents were observed in the cyclic voltammograms (CV) for Co3[Co(CN)6]2/Fe3O4 in comparison with the CV of isolated Co3[Co(CN)6]2. This increase was attributed to supramolecular charge transfer between the cobalt Prussian blue analogue and the magnetic NPs and the larger amount of electroactive species on the electrode. Transmission electron microscopy images showed well-defined Co3[Co(CN)6]2 nanocubes that had edge lengths of 21–140 nm and were decorated with spherical magnetite NPs less than 10 nm in diameter. Interestingly, an intimate contact between the nanocubes and aggreg...