CuS Decorated Functionalized Reduced Graphene Oxide: A Dual Responsive Nanozyme for Selective Detection and Photoreduction of Cr(VI) in an Aqueous Medium

Abstract

Design of functional nanomaterials as peroxidase mimics has attracted great attention due to promising applications in numerous fields, including biosensing, cancer diagnostics, immunoassays, environmental remediation, etc. Herein, we report a facile synthesis method for the decoration of semiconducting CuS nanoparticles on functionalized reduced graphene oxide composite (CuS-frGO). The CuS-frGO exhibits excellent peroxidase mimetic activity as well as photocatalytic properties. Indeed, the CuS-frGO catalyzes the decomposition of H2O2 to •OH radicals in the presence of Cr(VI) in acidic condition. The produced •OH radicals react with terephthalic acid, which acts as •OH scavenger, resulting in the formation of 2-hydroxyterephthalic acid exhibiting a fluorescence emission band at 425 nm. Based on this mechanism, CuS-frGO is utilized as a peroxidase mimic for the sensing of an inorganic pollutant, Cr(VI) ions, in aqueous medium. The proposed simple fluorescence technique with high selectivity and sensitivity...