Reusable electrochemical sensor for bisphenol A based on ionic liquid functionalized conducting polymer platform

• A novel conducting polymer-ionic liquid electrochemical sensor was fabricated.
• The sensor exhibits excellent electrochemical activity for subsequent detections.
• The sensor allows 77 replicate measurements of 10 μM bisphenol A (RSD=1.95%).
• The assay shows good recovery for bisphenol A released from plastic water bottles.

The toxicity of bisphenol A (BPA) has attracted considerable attention, and the reported electrochemical sensors for BPA need further improvement in reusability due to serious surface fouling. In this study, a composite film is designed aiming to provide both an accurate and repeatable platform for BPA determination. The conducting poly(3,4-ethylenedioxythiophene) film (PEDOT) and ionic liquid 1-butyl-3-methylimidazolium bromide (BMIMBr) were modified onto screen-printed carbon electrodes (SPCE) by electropolymerization and drop/spin methods, respectively. The surface characteristics of the composite film were characterized by field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS) and surface water contact angle experiments. The composite film-modified electrodes exhibited a linear response to BPA in the range of 0.1–500 µM in pH 7.0 phosphate buffer solution (PBS) under optimized flow-injection amperometry. The method sensitivity and detection limit (S/N=3) were 0.2661 μA μM−1 (2.419 μA μM−1 cm−2) and 0.02 µM, respectively. A relative standard deviation of 1.95% was obtained for 77 successive measurements of 10 µM BPA, and the repeatability outperformed previously reported work. The proposed method was applied to detect BPA released from plastic water bottles using the standard addition method, and satisfactory recoveries were obtained. The electrochemical assay was validated by comparison with the chromatographic method, and the results showed good agreement between the two methods.

An electrochemical assay for the determination of bisphenol A was developed taking advantage of the unique properties of the conducting polymer-ionic liquid composites, and the use of flow system to achieve good accuracy and high stability.Figure optionsDownload as PowerPoint slide