LAUSR

Abstract Nanomaterials-based peroxidase mimicking with attractive catalytic activity is an appropriate approach to receive the challenges for replacing natural enzymes. Here, we have been reported rGO/CM based peroxidase mimicking nanocatalyst for sensitive and selective detection of H2O2 and glucose. Time-dependent hydrothermal synthesis of CM nanoparticles with different morphologies and their composites have been designed for glucose sensing application. rGO/CM (6 h) (2:1) catalyst was found to be an excellent intrinsic peroxidase-mimicking nanozyme to oxidize 3, 3′,5, 5′-tetramethylbenzidine (TMB) in the presence of H2O2. This nanozyme holds better affinity towards TMB than natural enzyme-like horseradish peroxidase (HRP) and other nanozymes. Peroxidase–mimicking activity and enzyme kinetics of rGO/CM (6 h) (2:1) catalyst follows the Michaelis – Menten model. This novel metal-free highly sensitive colorimetric biosensor detects H2O2 and glucose precisely. Limit of detection (LOD) and linearity range for H2O2 were found to be 0.15 μM and 1–10 μM whereas for glucose it was 0.43 μM and 1–50 μM respectively. The sensitive and selective detection makes this catalyst as an effective biosensor for various potential applications such as clinical diagnosis, pharmaceutics, and food industry.