Electrochemical immunosensor for ethinylestradiol using diazonium salt grafting onto silver nanoparticles-silica-graphene oxide hybrids
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Data
2016-01-15
Autores
Cincotto, Fernando H. [UNESP]
Martinez-Garcia, Gonzalo
Yanez-Sedeno, Paloma
Canevari, Thiago. C.
Machado, S. A. S. [UNESP]
Pingarron, Jose M.
Título da Revista
ISSN da Revista
Título de Volume
Editor
Elsevier B.V.
Resumo
This work describes the preparation of an electrochemical immunosensor for ethinylestradiol (EE2) based on grafting of diazonium salt of 4-aminobenzoic acid onto a glassy carbon electrode modified with silver nanoparticles/SiO2/graphene oxide hybrid followed by covalent binding of anti-ethinylestradiol (anti-EE2) to activated carboxyl groups. A competitive immunoassay was developed for the determination of the hormone using peroxidase-labeled ethinylestradiol (HRP-EE2) and measurement of the amperometric response at -200 mV in the presence of hydroquinone (HQ) as redox mediator. The calibration curve for EE2 exhibited a linear range between 0.1 and 50 ng/mL (r(2)=0.996), with a detection limit of 65 pg/mL. Interference studies with other hormones related with EE2 revealed the practical specificity of the developed method for the analyte. A good reproducibility, with RSD=4.5% (n=10) was also observed. The operating stability of a single bioelectrode modified with anti-EE2 was maintained at least for 15 days when it was stored at 4 degrees C under humid conditions between measurements. The developed immunosensor was applied to the analysis of spiked urine with good results. (C) 2015 Elsevier B.V. All rights reserved.
Descrição
Palavras-chave
Ethinylestradiol, EE2, Electrochemical immunosensor, Silver nanoparticles, Graphene oxide, Urine
Como citar
Talanta. Amsterdam: Elsevier Science Bv, v. 147, p. 328-334, 2016.