Vanadium Nitride@Carbon Nanofiber Composite: Synthesis, Cascade Enzyme Mimics and its Sensitive and Selective Colorimetric Sensing of Superoxide Anion

Abstract

Nanozymes featuring with favorable activity, good stability and easy scale-up production, are promising to replace natural enzymes for various applications. However, it remains the challenge to explore the cascade reactions of multi-enzyme mimics, aiming at synergistic catalysis for various applications. Herein, vanadium nitride nanoparticles deposited on carbon nanofibers (VN@CNFs) composite was facilely prepared by typical electrospinning route with subsequently ammonia reduction process. The nanocomposite showed excellent two cascade enzyme mimicking activities, peroxidase (POD)- and superoxide dismutase (SOD)-like. Additionally, their catalytic mechanisms were systematically researched. On the basis of SOD-like and POD-like as cascade enzyme, a selective and sensitive colorimetric detection of superoxide anion (O 2 •− ) was explored, which have two linear parts, 0.05−30 μM and 30−250 μM O 2 •− with the LOD of 0.0167 μM (S/N=3). The as-proposed method was applicable to practical samples detection with satisfactory accuracy and recovery. Therefore, the VN@CNFs composite shows great prospect in biosensing, superoxide anion removal and biocatalysis.

Keywords: VN@CNFs nanocomposite, Cascade enzyme mimics, Superoxide anion sensing, Colorimetric sensor