Development of a poly(alizarin red S)/ionic liquid film modified electrode for voltammetric determination of catechol

• This study is the first to conduct electroploymerization of ARS in RTILs.
• BMIMBF4 was successfully mixed in polymeric ARS film.
• PARS/BMIMBF4 film was tighter, smoother and better electrochemical property.
• PARS/BMIMBF4/GCE showed superior performance for catechol determination.

A novel modified electrode for voltammetric catechol determination was fabricated by electroploymerization of alizarin red S (ARS) onto a glassy carbon electrode (GCE) in one kind of room-temperature ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate, BMIMBF4). The polymeric ARS/ionic liquid (PARS/BMIMBF4) film modified electrode was characterized by using scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and electrochemical methods. The EDX, XPS and FTIR results indicated that PARS/BMIMBF4 film was successfully obtained. Compared with the GCE modified by electroploymerization of ARS in aqueous solution, the GCE modified by electroploymerization of ARS in BMIMBF4 showed smoother and more compact morphology for coating and better electroanalytical properties. Given the combined electrochemical activity of PARS and excellent conductivity of BMIMBF4, the PARS/BMIMBF4/GCE has been successfully used for catechol determination by differential pulse voltammetry (DPV) with a linear range of 0.10 to 500 μM. The sensitivity and detection limit are 42 nA/μM and 0.026 μM, respectively. The PARS/BMIMBF4 modified electrode was successfully applied to the determination of catechol in real water samples and may serve as a simple but high-performance sensor for the determination of some environmental pollutants.