Electrochemical sensing of terabromobisphenol A at a polymerized ionic liquid film electrode and the enhanced effects of anions

Abstract

1-[3-(N-pyrrolyl)propyl]-3-butylimidazolium tetrafluoroborate (PPBimBF4), a functional ionic liquid, was prepared successfully. It was employed as a monomer to fabricate a polymerized ionic liquid (PIL) film on glassy carbon electrode surface with potential step technique. Scanning electron microscopy (SEM) and electrochemical impedance microscopy (EIS) were used to characterize the morphology and the electrochemical properties of the PIL film electrode, respectively. Voltammetry was applied to investigate the electrochemical behaviors of tetrabromobisphenol A (TBBPA) at the PIL film electrode. An irreversible electrochemical oxidation process was found for TBBPA at the PIL film electrode surface. The influence of some anions on the electrochemical response of TBBPA was also investigated. The results demonstrated that the PIL film with dodecyl sulfonate anion [poly(PPBim-DS)] can give maximum peak current for TBBPA. Experimental conditions including the film thickness, pH values, accumulation potential, and accumulation time were optimized for TBBPA determination. Under optimized conditions, an effective electrochemical method for TBBPA determination was developed. The oxidation peak current is linearly related to the TBBPA concentration in the range from 5.0 × 10−8 to 1.0 × 10−5 mol L−1 with a detection limit of 2.0 × 10−8 mol L−1 (S/N = 3). In addition, the electrochemical sensing platform was used to detect TBBPA in South Lake water samples.