High-Performance Electrochemical Sensor Based on MIL-101(Fe) for Simultaneous Detection of Hydroquinone, Catechol, and Resorcinol

Recently, metal-organic frameworks (MOFs) have attracted significant attention due to their remarkable properties, which make them up-and-coming candidates for sensing applications. In this work, we report the solvothermal synthesis of MIL-101(Fe), which was successfully drop-cast onto screen-printed carbon electrodes (SPCEs) without the need for any binders or surfactants. The resulting sensor was evaluated for the simultaneous electrochemical detection of three environmentally hazardous dihydroxybenzene isomers: hydroquinone (HQ), catechol (CC), and resorcinol (RS). Electrochemical techniques including cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS) demonstrated that MIL-101(Fe) exhibits high electrocatalytic activity and excellent selectivity toward the target analytesThe sensor achieved wide linear response ranges of 1–700 μM for HQ and CC, and 0.1–290 μM for RS, with low detection limits of 0.2 μM (HQ), 1.0 μM (CC), and 0.1 μM (RS). Furthermore, the sensor was applied to real water samples (tap, mineral, and seawater) using the standard addition method. Satisfactory recovery rates ranging from 89.26% to 105.08%, with relative standard deviations (RSD) between 0.77% and 5.64%, confirmed its practical applicability. These results highlight the potential of MIL-101(Fe)-based sensors as reliable and low-cost platforms for environmental monitoring of phenolic contaminants.