ABSTRACT Catechol and Hydroquinone are considered to be main organic pollutants in water, and have a threat to human health and ecology security. It is imperative to establish a detection method of catechol and hydroquinone with high selectivity and sensitivity.In this work, a composite of L-Cysteine and nickel cobaltite co-functionalised graphene oxide was synthesised successfully by a facile hydrothermalmethod.The morphology and structure of the as-prepared composite was characterised by scanning electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. The results revealed that the final product formed a 3D framework with urchin-like nickel cobaltite nanoparticle tightly packed on the layers of graphene oxide. The electrochemical properties of the composite modified glassy carbon electrode for detecting hydroxybenzeneisomers (hydroquinone and catechol) were tested by cyclic voltammetry and differential pulse voltammetry. The results discovered that the modified electrode exhibited an excellent repeatability and anti-interference towards the detection of catechol and hydroquinonewith linear response in the range of 10–140 μM and 10–200 μM, respectively.