Electrochemical paper-based immunocapture assay for the quantitative determination of ethinylestradiol in water samples

M.L. SCALA BENUZZI; GERMAN A. MESSINA;; F.A. BERTOLINO; S.V. PEREIRA; PEDRO ARANDA,; JULIO RABA.

Congreso; 28th Anniversary World Congress on Biosensors; 2018

Ethinylestradiol (EE2) is a synthetic estrogen female sex hormone which is used as a contraceptive therapy. The determination of synthetic estrogen has attracted much attention since these compounds were included in the endocrine disrupting chemicals and it?s able to cause the deleterious reproductive dysfunction of animals and humans. Due the problems mentioned previously, is important the determination of EE2 in water samples. Therefore, we present a method that combined the use of paper microzones modified with silica nanoparticles (SNs) and anti-EE2 specific antibodies for the capture and pre-concentration of EE2 from river water samples. After the pre-concentration procedure, the paper microzones were placed on the surface of a screen-printed carbon electrode modified with electrochemically reduced graphene. The bound EE2 is desorbed adding onto the paper microzones a diluted solution of sulfuric acid. Finally, recovered EE2 is electrochemically detected by Osteryoung square wave voltammetry. The non-sophisticated equipment required, the adequate recovery values obtained (from 97% to 104%, with a relative standard deviation of less than 4.9%) and the appropriate LOD value (0.1 ng L-1) achieved by our immunocapture sensor present appropriate analytical figures of merit, particularly when the routine quantification of EE2 is considered. The developed method is suitable for the determination of EE2 in environmental samples after a simple step of preconcentration. It has the advantages of low cost, wide linear range, reproducibility, accuracy and low DLs. The developed procedure was successfully applied to direct determination of EE2 at trace levels in water samples.