A facile preparation of montmorillonite-supported copper sulfide nanocomposites and their application in the detection of H2O2

Well-dispersed nanocomposites (CuS-MMT nanocomposites) based on copper sulfide (CuS) and Ca-montmorillonite (Ca2+-MMT) were prepared via a simple and facile method and were characterized by transmission electron microscopy (TEM), high resolution TEM, powder X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS). The as-prepared CuS-MMT NPs were for the first time demonstrated to possess intrinsic peroxidase-like activity towards typical peroxidase substrates such as 3,3',5,5'-tetramethylbenzidine (TMB) for hydrogen peroxide (H2O2). Interestingly, the CuS-MMT nanocomposites as peroxidase mimics could rapidly catalyse to oxidise the substrate TMB into blue oxTMB only in 30 s observed by the naked eye. The reaction catalyzed by the CuS-MMT nanocomposites followed the Michaelis-Menten kinetics, which showed good affinity towards both TMB and H2O2, respectively. Taking the advantage of the high peroxidase-like activity, the as-prepared CuS-MMT nanocomposites were designed to establish a novel colorimetric sensor for H2O2 with a wide linear range from 3 x 10(-5) to 2 x 10(-4) M. Moreover, the rapid, simple and sensitive TMB-H2O2-[CuS-MMT] colorimetric platform holds great promising applications in the pharmaceutical, clinical and industrial detection of H2O2. (C) 2016 Elsevier B.V. All rights reserved.