Colorimetric ascorbic acid sensing from a synergetic catalytic strategy based on 5,10,15,20-tetra(4-pyridyl)-21H,23H-porphyrin functionalized CuS nanohexahedrons with the enhanced peroxidase-like activity

Abstract Artificial peroxidase mimics are indispensable for establishing the colorimetric sensing platform to detect rapidly H2O2 and related biomolecules. In this work, 5,10,15,20-tetra(4-pyridyl)-21H,23H-porphyrin (TPyP) functionalized CuS nanohexahedrons were prepared and was found to possess an excellent peroxidase-like activity. TPyP-CuS effectively catalyzed the oxidation of colorless 3,3´,5,5´-tetramethylbenzidine (TMB) by H2O2 into a blue oxTMB, distinguished visually only within 1 min. Fluorescent data reveal that the higher catalytic activity of TPyP-CuS is from lots of OH generated from H2O2. Based on the peroxidase-like activity of TPyP-CuS, a visual sensing platform was constructed to rapidly detect H2O2 in a wide linear range of 1.0–8.0 mM with a relatively lower limit of detection (LOD) of 121.8 μM as well as ascorbic acid (AA) in a linear range from 1 to 30 μM with a low detection limit of 0.419 μM.