In-situ Polymerization of N-(3-aminobenzyl)-N, N-dimethyl-N-dodecyl Ammonium Bromide on Glassy Carbon Electrode for Estradiol Detection

Estradiol is a common endocrine disrupting chemicals. Therefore, it is necessary to develop simple, sensitive and rapid methods for testosterone bioanalysis. In this work, poly (N-(3-aminobenzyl)-N,N-dimethyl-N-dodecyl ammonium bromide) (PAS), a novel cathodic organic electrochemiluminescence (ECL) emitter, was synthesized by in-situ polymerization of the corresponding monomer on glass carbon electrode. The PAS ECL system was constructed with the PAS modified electrode, and potassium persulfate (KPS) as oxidizing agent and co-reactant. It was applied to the ECL detection of estradiol. According to the results of fluorescence and dynamic light scattering (DLS), mixed micelle of PAS and estradiol was formed. The combination of PAS with estradiol intensified the fluorescence of the ECL system and enlarged the colloidal size. Hydrogen bonds and electrostatic interaction may play a role in the combination. The linearity for estradiol quantification is 6 pM to 1.5 nM with a LOD of 0. 1 pg/mL. The modified electrode can be easily renewed by washing with ethanol and water and the relative error in estradiol measurement does not exceed ± 7% in 7 time recycling. The detection of estradiol in urine sample qualified the ECL system with a recovery of 94.5 to 105% and the calculated coefficient of variation of 3.8%. This indicates that the PAS ECL system has the potential to detect estradiol in urine.