Electro Oxidation and Determination of Estriol Using a Surfactant Modified Nanotube Paste Electrode

Abstract

The electrocatalytic oxidation of Estriol (ET) has been studied by surfactant
modified nanotube paste electrode. The sensor was prepared using carbon nanotubes and
silicone oil, Carbon nanotube paste electrode (CNTPE) modified with Sodium dodecyl sulfate
(SDS) surfactant, the modified electrode highly sensitive for the determination of ET. Cyclic
voltammetry (CV) and differential voltammetry (DPV) techniques were used to investigate the
ET. A enrich improvement in the microscopic area of the electrode produced in a increase of
the peak current of ET oxidation. CV has been used as a electrochemical sensitive analytical
method for the detection of small amounts of ET, Two linear ranges have been procured for
the ET concentration between the ranges of 6.0 × 10−6 to 2.0 ×10−5 and 2.5 × 10−5 to 1.5 ×
10−4 M ET. The detection limit of this electrode is 3.2×10−7 M and the quantification limit is
10×10−7 M. This sensor has a remarkably good sensitivity for the ET determination in the
presence of real samples. The recovery for the ET detection in clinical sample was obtained as
97.2-102 % with a good RSD of 4.2%, (on the basis of 5 repeated determinations). These good
qualities make the fabricated sensor suitable for the experiments of the trace amounts of ET
in pharmaceutical and clinical preparations.