A simple and efficient electrochemical sensing platform for simultaneous detection of hydroquinone (HQ), catechol (CC) and resorcinol (RC) based on in-situ prepared sodium hydroxide (NaOH) nanorods was reported for the first time. Sodium hydroxide (NaOH) nanorods on glassy carbon electrode (GCE) was synthesized via one electrochemical deposition step in NaOH solution using constant current. The affecting factors including content of NaOH solution, deposition current and deposition time were investigated. The obtained electrodes were also examined by scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The electrochemical behaviour analysis and dynamic study indicated that the three dihydroxybenzene isomers can be catalytically oxidized and discriminated simultaneously on the proposed electrode. Using square wave voltammetry (SWV), the ultrasensitive and simultaneous detection of HQ, CC and RC was realized with wide linear range from 0.03 to 1500 mu M and low detection limit of 0.01, 0.01, 0.09 mM, respectively. The detection of them in real water samples was also successfully performed and good recovery was obtained. (c) 2019 Elsevier Ltd. All rights reserved.