Electrocatalytic oxidation and determination of estradiol using an electrode modified with carbon nanotubes and an ionic liquid

A sensitive method for the determination of estradiol is presented that is based on an electrode modified with multi-walled carbon nanotubes (MWNTs) along with an ionic liquid. The resulting electrode showed more sensitive voltammetric response to estradiol than other electrodes modified with MWNTs. The peak current for estradiol is linearly related to concentration over two decades, and the limit of detection is 5 nM. The method was applied to the determination of estradiol in rabbit blood serum and in environmental waters. The recoveries were 95.3-104.0% and 97.0-104.7%, respectively.