A simple hydroxylated multi-walled carbon nanotubes modified glassy carbon electrode for rapid amperometric detection of bisphenol A

A novel amperometric sensor for the determination of bisphenol A (BPA) was fabricated using a glassy carbon electrode easily modified with multi-walled carbon nanotubes functionalized with hydroxyl groups. The catalytic activity of the modifier toward the oxidation of BPA was demonstrated by cyclic voltammetry, giving a well-defined peak at 0.55 V in sodium glycine buffer solution (pH 8.0). The flow injection analysis (FIA) system of BPA exhibited a linear response in the 1-24 μg L−1 concentration range, with a detection limit of 0.81 μg L−1. The current reached the steady-state value with a very fast response time (less than 10 s). The proposed method was successfully applied for the determination of BPA in real samples (water contained in plastic and baby bottles) with satisfactory results, in optimum agreement with those obtained by an independent HPLC method. In the light of our results and previous reports, the proposed system combines good analytical performance with simplicity of sensor fabrication, being ideal for routine sensing applications.