2(3),9(10),16(17),23(24)-Octamethoxyphthalocyanine-Cu/CuFe2O4 nanocomposites with enhanced peroxidase-like activity for the sensitive colorimetric determination of glutathione

Abstract

In this work, 2(3),9(10),16(17),23(24)-octamethoxyphthalocyanine (Pc(OH)₈) was first used to modify Cu/CuFe₂O₄(Cu/CFO) nanospheres, and Pc(OH)₈–Cu/CFO nanocomposites with enhanced peroxidase mimetic enzyme activity was obtained compared to the performance of Cu/CFO alone. SEM, XRD, and XPS were used to study the surface morphology, phase composition and elemental analysis of the newly synthesized Pc(OH)₈–Cu/CFO. Using TMB as the chromogenic substrate, Pc(OH)₈–Cu/CFO accelerate the oxidation process of chromogenic substrate 3,3′,5,5′- tetramethylbenzidine (TMB) by hydrogen peroxide in three minutes. The catalytic oxidation mechanism of Pc(OH)₈–Cu/CFO on TMB was comprehensively investigated through free radical and fluorescence probe experiments. Based on the excellent catalytic performance of the composite materials, a simple and fast colorimetric sensing platform for the colorimetric detection of H₂O₂ and glutathione (GSH) was constructed in the range of 0.6–5 mM and 2–10 μM with detection limits (LODs) of 0.35 mM and 0.55 μM, respectively. In addition, using Pc(OH)₈–Cu/CFO colorimetric detection for GSH has a lower detection limit, good selectivity and high sensitivity, which is expected to become an ideal material for GSH colorimetric detection.