Metal-Free 2(3),9(10),16(17),23(24)-Octamethoxyphthalocyanine-Modified Uniform Cosn(Oh)(6) Nanocubes: Enhanced Peroxidase-Like Activity, Catalytic Mechanism, And Fast Colorimetric Sensing For Cholesterol

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 .O-2-) 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 mu M. The contents of total cholesterol in serum samples is monitored satisfactorily and distinguished visually.