Metal-Free 2(3),9(10),16(17),23(24)-Octamethoxyphthalocyanine-Modified Uniform CoSn(OH)<sub>6</sub> Nanocubes: Enhanced Peroxidase-like Activity, Catalytic Mechanism, and Fast Colorimetric Sensing for Cholesterol
Haoyuan Lyu, Dexin Yin, Baocan Zhu, Guang Lu, Qingyun Liu, Xianxi Zhang, Xiao Zhang
Abstract
In this paper, a novel metal-free 2(3),9(10),16(17),23(24)-octamethoxyphthalocyanine (Pc(OH)8) has been first used to modify CoSn(OH)6 nanocubes to obtain the Pc(OH)8/CoSn(OH)6 nanocomposites, which possess the enhanced peroxidase-like performances, compared with that of pure CoSn(OH)6. Pc(OH)8/CoSn(OH)6 can rapidly accelerate the process of catalytic oxidation of the chromogenic substrate 3,3′,5,5′-tetramethylbenzidine (TMB) by H2O2 in 2 min. The peroxidase-like performance of Pc(OH)8/CoSn(OH)6 is consistent with the Michaelis–Menten kinetics. The catalytic mechanism of Pc(OH)8/CoSn(OH)6 from the generated active species (•OH and •O2–) in the catalytic system has been comprehensively investigated by florescent probe and radical quencher experiments. Based on this, a fast colorimetric sensing platform for H2O2 detection and cholesterol is constructed in the range of 0.4–0.8 mM and 0.1–0.9 mM with a limit of detection (LOD) of 0.0914 mM and 10.7 μM. The contents of total cholesterol in serum samples is monitored satisfactorily and distinguished visually.