Flexible electrochemical sensor constructed using an active copper center instead of unstable molybdenum carbide for simultaneous detection of toxic catechol and hydroquinone

A new electrochemical sensor based on a [email protected]x-modified polyethylene terephthalate electrode spin coated with PEDOT ([email protected]x-PEDOT/PET) was developed for simultaneous determination of catechol (CT) and hydroquinone (HQ). A zerovalent copper and copper(II) oxide intercalated molybdenum oxide MoOx (x = 2 or 3) hybrid nanomaterial ([email protected]x) by introducing active copper catalytic centers into the Mo2[email protected]x system based on unstable Mo2C, and replaced Mo2C using a simple hydrothermal method. At room temperature, the [email protected]x-PEDOT/PET electrode demonstrated the lowest detection limits of 0.216 and 0.221 μM for CT and HQ (S/N = 3), respectively. In addition, the applicability of this method was proven by the recovery of CT and HQ in spiked tap water samples. The [email protected]x-PEDOT/PET flexible electrode had strong anti-interference ability, good repeatability and long-term stability. It was used in the detection of CT and HQ in Nanjing tap water, the recoveries of CT and HQ calculated from the i–t curve were 99.36 % and 97.56 %, respectively. Most importantly, the flexible electrode could still maintain relatively stable electrochemical responses under different bending and folding conditions, and the obtained relative standard deviations (RSDs) were 2.78 % and 1.53 %, respectively. This flexible property holds promise for the construction of wearable electrochemical sensors.