Enhanced peroxidase-like activity of copper phosphate modified by hydrophilic phytic-acid and its application in colorimetric detection of hydrogen peroxide

Abstract

The Cu3(PO4)2·3H2O was modified by hydrophilic phytic-acid (PA/Cu3(PO4)2·3H2O) using a facile co-precipitation method. The peroxidase-like activities of Cu3(PO4)2·3H2O and PA/Cu3(PO4)2·3H2O were demonstrated by catalyzing the peroxidase substrate 3,3,5,5-tetramethylbenzidine in the presence of hydrogen peroxide. The catalytic activity of PA/Cu3(PO4)2·3H2O is about four times than that of Cu3(PO4)2·3H2O, indicating that the peroxidase activity can be enhanced by the introduction of PA. Then, the as-prepared PA/Cu3(PO4)2·3H2O was used to develop a colorimetric method for hydrogen peroxide detection with linear range of 0.1–5.0 mM and detection limit of 0.079 mM. Finally, the applicability of PA/Cu3(PO4)2·3H2O-based assay was validated by the detection of hydrogen peroxide in milk samples, and the recoveries were 92.4%-101.7%. The developed strategy highlights opportunity for the design of inorganic materials with enhanced inherently peroxidase-mimicking performance using PA.