Simultaneous analysis of catechol and hydroquinone by polymelamine/CNT with dual-template molecular imprinting technology

Dual-template molecularly imprinted polymer/carbon nanotubes/grassy carbon electrode (MIP/CNTs/GCE) was constructed by electropolymerizing a layer of bimolecular imprinted film with melamine (Mel) as functional monomer, hydroquinone (HQ) and catechol (CC) as template molecules on CNTs modified GCE. The morphology, structure and electrochemical properties of MIP/CNTs/GCE were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and electrochemical technology, respectively. The experimental parameters for the construction of sensor were optimized in detail, which includes the reagent molar ratio, the electropolymerization cycles, the elution time and the pH value of the electrolyte. Under the optimal conditions, the simultaneous detection of HQ and CC was realized via cyclic voltammetry (CV) and differential pulsed voltammetry (DPV). Compared with CNTs/GCE, molecularly imprinted membrane can significantly enhance its response current to HQ and CC. At the same time, both the linear range of HQ and CC measured by DPV are 10–100 μM, with the detection limits of 3.1 μM and 3.5 μM, respectively. The electrode also owned good reproducibility and stability. Finally, MIP/CNTs/GCE was successfully utilized for the detection of HQ and CC in river water.