Vanadium doped ZIF-L derived V-NC peroxidase-like nanozymes for tannic acid sensing

We reported a facile strategy to synthesize V-NC peroxidase-like nanozyme , showing 27.5-fold higher peroxidase-like activity than NC. The V-NC has been used for developing a simple, sensitive and selective colorimetric detection platform for sensing tannic acid . • V-NC nanozyme was prepared by a simple pyrolysis strategy. • V-NC shows 27.5-fold higher peroxidase-like activity than NC. • V-NC as memetic peroxidase can be used for colorimetric detection of tannic acid. • The method was successfully used to determine tannic acid in tea samples. Transition metal-based nitrogen doping carbon nanozyme has attracted great attention owning to their high potential to replace natural enzymes. In this study, we prepared novel vanadium doped ZIF-L derived N-doped carbon nanozyme (V-NC) via facilely pyrolysis strategy. The cross-shaped morphology endows V-NC with unique V-N x active sites, hierarchical pore character and large specific surface area, leading to its good peroxidase-mimetic activity. The steady-state kinetics trials revealed the low K m values of V-NC for TMB and H 2 O 2 , demonstrating its good affinity to TMB and H 2 O 2 . Mechanism research revealed that the excellent peroxidase-like activity of V-NC resulted from co-participation of • OH and O 2 •− , which were confirmed by reactive oxygen species (ROS) scavenging experiments and EPR trials. Under optimized operational conditions, and by virtue of the antioxidant properties of tannic acid (TA), a colorimetric sensing assay based on the peroxidase-like activity of V-NC was developed for sensitive detection of TA in the 0.1–2.5 µM linear range with low detection limit of 19.8 nM and the relative standard deviation (RSD, n = 3) of below 5%. This work renders a new idea for designing and developing high activity N-doped carbon nanozyme, and provides an accurate and feasible assay for the analysis of TA in real samples.