Facile Synthesis of Iron Oxide Nanozymes for Synergistically Colorimetric and Magnetic Resonance Detection Strategy

Iron oxide nanomaterials with mimic enzymes activity have been paid more attention in the clinical diagnosis field. The modified surface molecules would influence the catalytic activity of nanozyme, which is worth studying. Furthermore, the traditional detection strategy is based on colorimetric change of substrates, however, the optical signal is easy to be interfered in complex biological applications. In our research, an efficient and facile preparation strategy was developed to obtain functional artificial nanozymes. Herein, three kinds of surfactants, including citrate acid, poly(ethylene glycol) bis (carboxymethyl) ether and tannic acid have been applied to modify these nanomaterials that showed uniform size, high soluble dispersity and stability. Furthermore, these nanozymes exhibited different peroxidase-like activity to catalyze the hydrogen peroxide and 3,3′,5,5′-tetramethylbenzidine. More importantly, magnetic relaxation effect of iron oxide nanozymes was found to be changed during the catalytic reaction. In addition, the relationship between the magnetic signal of nanozymes and the substrate concentration showed a good linear dependence. Combined with the natural enzymes, the magnetic detection of iron oxide nanozymes also exhibited excellent substrate specificity. On these bases, a dual-function specific assay was constructed and further used for glucose detection. In conclusion, this study demonstrated an efficient iron oxide nanozymes preparation method and constructed a new synergistically colorimetric-magnetic diagnosis strategy.