Synthesis, structure and effective peroxidase-like activity of a stable polyoxometalate-pillared metal–organic framework with multinuclear cycles

Abstract

A stable polyoxometalate (POM)-pillared metal–organic framework (MOF) with 6-nuclear Cu-pz and 10-nuclear Cu-pz-Cl cycles, [Cu5(pz)6Cl][SiW12O40] (CuSiW12) (pz = pyrazine), has been hydrothermally synthesized and structurally characterized. Inspired by the reported horseradish peroxidase (HRP) and other enzyme mimics, the peroxidase-like activity of CuSiW12 was investigated in detail to catalyze the oxidation of the substrate 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of H2O2, which exhibits excellent peroxidase-like activity than that of pristine silicotungstic acid. Moreover, the detection of H2O2 was also studied in the TMB/CuSiW12/H2O2 system, which exhibits good sensitivity, wide linear range (1–60 μM), the lowest detection limit (0.10 μM) and faster response time towards H2O2 (2 min) to date, to the best our knowledge, maybe due to the maximized synergistic effects of SiW12 clusters, pyrazine molecules, Cu ion and the stable structure.