Simultaneous and ultrasensitive detection of three dihydroxybenzene isomers based on 3D chain structure-modified MOF...

To prevent phenolic compounds from threatening ecological environment safety and human health, the development of rapid and sensitive methods is vital. Herein, a novel Ketjen black (KB) and multi-walled carbon nanotubes (MWCNTs)- multifunctionalized metal-organic framework nanocomposite (ZIF-67/KB-MWCNTs) was synthesized, which was used for the modification of bare electrode (GCE), achieving simultaneous and ultrasensitive detection of hydroquinone (HQ), catechol (CC), and resorcinol (RS) in environmental water. The proposed electrochemical sensor (ECS) was constructed based on the synergistic effect of ZIF-67 with an ultra-large specific area and KB-MWCNTs with 3D chain structure and high conductivity resulted in both high electrocatalysis and fast electron transfer. All prepared materials and GCE/ZIF-67/KB-MWCNTs were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Nitrogen adsorption and desorption, X-ray photoelectron spectroscopy (XPS), infrared spectroscopy (FT-IR), electrochemical impedance spectroscopy (EIS) and electrochemistry methods such as cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Under the optimum conditions, the detection limits of 0.015 μM, 0.024 μM and 0.198 μM were obtained for HQ, CC, and RS, respectively. More importantly, the as-prepared modified electrode exhibited outstanding specific recognition toward electrooxidation of three dihydroxybenzene isomers with three well-separated peaks. This sensor showed satisfactory anti-interference ability and provided reliable assay results.