Assemble multi-enzyme mimic tandem Mn3O4@ g-C3N4 for augment ROS elimination and label free detection

Over decades, nanozyme serves as an alternative to natural enzymes that make up the most of intrinsic disadvantages of bio enzymes. The recent research have focused on development of multi enzyme mimic nanomaterials so that they can be equipped for multifunctional action which unlocks the potential application of nanomaterials in the field of bio medical, bio-sensing and sustainable chemistry. Here in layered 2D g-C3N4 have been synthesized and grafted with spherical Mn3O4 by solid state mixing method. The loading of spherical Mn3O4 NPs on the surface of g-C3N4 were easily navigated by FT-IR, FE-SEM and HR-TEM analysis. Powder X-ray diffraction (XRD) method was used to determine the different phases involve in the formation of tetragonal Mn3O4 NPs on the 2D Nano layer g-C3N4. Fortunate to mixed valance state of Mn3O4, the composites Mn3O4@g-C3N4 showed multi enzyme mimic activity including superoxide dismutase (SOD), catalase (CAT), oxidase (OD) and peroxidase (POD), therefore it offers synergistic antioxidant abilities to over exposer of reactive oxygen species (ROS). Based on the excellent SOD-like enzyme activity of Mn3O4@g-C3N4, it successfully eliminated the active oxygen (O2 ·−) in cigarette smoke. Taking advantages of optimized oxidase activity a sensitive colorimetric probe has been developed to detect two isomeric phenolic pollutant hydroquinone (H2Q) and catechol (CA) with a promising linear range and low detection limit. Along with excellent sensitivity and selectivity the current probe endowed with visual discrimination of two isomers by naked eye.