Estradiol electrochemical detection

Hayashi, N. Hayata, K. Sekiba, K. Rapid and simultaneous measurement of estrone, estradiol, estriol and estetrol in serum by high performance liquid chromatography with electrochemical detection. Acta Med.Okayama., 1985, 39, 143-153... 

Increased selectivity and prevention of passivation of the BDD surface may be also achieved by its modification. An enzyme-based amperometric sensor was proposed for detection of phenolic compounds by Notsu et al. BDD was anod-ically polarized for the introduction of hydroxyl groups onto its surface, then treated with (3-aminopropyl)triethoxysilane (APTES), and finally coated with a tyrosinase film cross-linked with glutaraldehyde. Tyrosinase catalyzes oxidadmi of phenol and various phenol derivatives to o-benzoquinone derivatives via catechol derivatives and thus the quinones generated are ready to be reduced electrochemically at an appropriate potential and obtained reduction currents serve as good analytical signals for the determination of the phenol derivatives. Bisphenol A and 17-/ -estradiol were detected at —0.3 V vs. Ag/AgCl with the detection limit of 1 pmol in FIA. However, the biosensor retained its activity only for a few days due to weak bonding of APTES to BDD surface. 

The metabolites of estradiol (estriol, and 2-hydroxy-, 4-hydroxy-, 6a-hydroxy-, and 15a-hydroxyestradiol) were well resolved on a 40°C Cig column (electrochemical detector, 0.8 V vs. Hg/Hg2Cl2) using a 60/40 methanol/water (50 mM ammonium phosphate buffer at pH 2.5) mobile phase. Elution was complete in 35 min [419]. Calibration curves of 0-40pmol injected were used. Detection limits ranged from 10-50 find injected (S/N = 3, analyte dependent). 

Liu X, Deng DKY (2(X)9) Picogram-detection of estradiol at an electrochemical immunosensor with a gold nanoparticle-protein G-(LC-SPDP)-scaffold. Talanta 77 1437-1443... 

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