Flexible Electrochemical Sensor Constructed Using an Active Copper Center Instead of Unstable Molybdenum Carbide for Simultaneous Detection of Toxic Catechol and Hydroquinone

•A flexible Cu-CuO@MoOx-modified PET plastic electrode is successfully fabricated.•The Cu-CuO@MoOx-PEDOT/PET can achieve simultaneous determination of CT and HQ.•The flexible sensor shows the excellent sensing performances for toxic pollutants.•The sensor shows an excellent reproductivity and anti-interference ability.•The sensor can maintain a stable electrochemical response under different bending.