A novel ascorbic acid electrochemical sensor based on spherical MOF-5 arrayed on a three-dimensional porous carbon electrode

Abstract

In this work, the spherical porous MOF-5 microstructures supported by three-dimensional (3D) kenaf stem-derived porous carbon (KSC) (denoted as MOF-5/3D-KSC) composites were constructed for ascorbic acid (AA) sensing. The formation of MOF-5/3D-KSC was verified by scanning electron microscopy, X-ray powder diffraction and energy dispersive X-ray spectroscopy. The results showed that spherical porous MOF-5 microstructures were evenly arrayed on the surface of 3D-KSC via a simple one-step hydrothermal method, which could greatly increase the effective surface area, stability and active sites. The MOF-5/3D-KSC composites were directly used to prepare integrated MOF-5/3D-KSC electrodes for AA sensing, and the integrated electrodes showed better performance for AA detection than traditional enzyme-based sensors and nonenzymatic sensors. The sensor exhibited good stability, wide linear range (0.7 μM to 11.5 mM) and low detection limit (0.24 μM). Hence, the MOF-5/3D-KSC composites could be a potential material for sensing platforms.