Simultaneous detection of dihydroxybenzene isomers in the environment by a free-standing flexible ZnCo2O4 nanoplate arrays/carbon fiber cloth electrode

The simultaneous determination of dihydroxybenzene isomers is highly valuable for early environmental monitoring, but it is still a challenge. In this work, a free-standing flexible electrode was prepared for the simultaneous detection of hydroquinone (HQ), catechol (CC), and resorcinol (RC). The bimetallic zinc/cobalt zeolitic imidazolate frameworks nanoplate arrays (Zn/Co-ZIF NPAs) grown in situ on the carbon fiber cloth (CFC) was fabricated by a facile static synthesis method, and the porous ternary ZnCo2O4 NPAs derived from Zn/Co-ZIF NPAs were formed by annealing in air. Due to the fast electron transmission, abundant active sites and excellent electrocatalytic properties with enzyme-like kinetic performance of the ZnCo2O4/CFC electrode, the as-proposed sensor showed a wilder linear response (2-500 μM), a lower detection limits (0.03 μM HQ, 0.06 μM CC and 0.15 μM RC) and a higher sensitivity (23.58 μA μM-1 cm-2 HQ, 17.72 μA μM-1 cm-2 CC, and 15.18 μA μM-1 cm-2 RC), respectively. More importantly, the proposed electrochemical sensor exhibited excellent detection performance in complex water samples, providing a strategy for the detection of other toxic substances in the ecological environment.