| In this work, hexacyanoferrate intercalated Ni/Al LDH (Ni/AleFe(CN)6 LDH) nanozyme was synthesized
by one-pot co-precipitation method and used for determination of chromium in water samples by
employing its peroxidase mimicking activity. The synthesized nanozyme can effectively catalyze the
oxidation of fluorometric peroxidase substrate terephthalic acid by H2O2 to produce a highly fluorescent
product. It was found that Cr(VI) promotes the peroxidase-like activity of Ni/AleFe(CN)6 LDH and this
effect was intensified by increasing the Cr(VI) concentration. Several variables affecting the fluorescence
intensity including the concentration of nanoparticles and reagents as well as reaction time were
investigated and optimized. Under the optimal conditions, good linearity was observed in the range of
0.067e10 mM Cr(VI), and limit of detection and quantification were found to be 0.039 and 0.131 mM,
respectively. Furthermore, the developed method showed good applicability for the determination of
total Cr based on the oxidation of Cr (III) to Cr (VI). The applicability of the proposed method was
demonstrated by analyzing various environmental water samples. The presented nanozyme displayed
superior benefits in terms of reusability, repeatability, cost and environment-friendly features. The
present work aims to expand LDHs based enzyme mimics to optical sensor fields. |