A magnetic zirconium hexacyanoferrate-based Prussian blue analog (MB@ZrHCF) nanozyme was synthesized using dopamine (DA) reduction-assisted method and employed for colorimetric PO43- sensing. The MB@ZrHCF exhibits enhanced peroxidase-mimicking activity and ultrafast catalytic rate via the color reaction of 3,3',5,5'-tetramethylbenzidine (TMB) oxidized by hydrogen peroxide (H2O2). The catalytic reaction mechanism of MB@ZrHCF catalyzing H2O2 to produce hydroxyl radical (∙OH) was studied. Then, MB@ZrHCF was successfully applied to the detection of H2O2. Additionally, the catalytic activity of the nanocomposite is inhibited due to the steric hindrance effect from the coordination of PO43- and Zr(IV) node. Based on this, the MB@ZrHCF nanozyme can be used to detect PO43- in two linear ranges (10-100 µM and 100-200 µM) with a limit of detection of 2.25 µM. The proposed colorimetric sensor possesses excellent selectivity and reliability for PO43- sensing, which can be successfully applied to detect PO43- in sea and tap water samples.
Keywords: Colorimetric sensor; Hydrogen peroxide; Magnetic zirconium-based Prussian blue analog; Peroxidase-like activity; Phosphate ion.
© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.