Electrochemical properties of estradiol at glassy carbon electrode modified with nano-Al 2O 3 film

Abstract

Nano-Al 2O 3 is dispersed onto the surface of the glassy carbon electrode (GCE). This nanostructured film modified GCE exhibits a great enhancement to the oxidation of estradiol (E 2), especially when adequate concentration of cationic surfactant such as cetyltrimethylammonium bromide (CTAB) is added into the sample solution. Due to the nanoparticle's unique properties and its inclination to selectively combine with some groups of bimolecules, as well as synergistic adsorption of E 2 and CTAB on the electrode surface, E 2 gives a more sensitive voltammetric response compared with bare GCE performed in the absence of CTAB. The lowest detectable concentration (3 σ) of E 2 is estimated to be 8×10 −8 mol l −1 (accumulation for 2 min). The linear relationship between peak current and concentration of E 2 holds in the range 4×10 −7–4×10 −5 mol l −1 ( R=0.9932). The electrochemical properties of E 2 on this modified electrode are investigated by linear scan voltammetry and cyclic voltammetry. Scanning electron microscope (SEM) and BET are employed to characterize the surface of the electrode modified with nano-Al 2O 3 film.