RESUMEN
This paper describes a novel, simple, and disposable immunosensor based on indium-tin oxide (ITO) sheets modified with gold nanoparticles to sensitively analyze heat shock protein 70 (HSP70), a potential biomarker that could be evaluated in diagnosis of some carcinomas. Disposable ITO coated Polyethylene terephthalate (PET) electrodes were used and modified with gold nanoparticles in order to construct the biosensors. Optimization and characterization steps were analyzed by electrochemical techniques such as electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Surface morphology of the biosensor was also identified by electrochemical methods, scanning electron microscopy (SEM), and atomic force microscopy (AFM). To interpret binding characterization of HSP70 to anti-HSP70 single frequency impedance method was successfully operated. Moreover, the proposed HSP70 immunosensor acquired good stability, repeatability, and reproducibility. Ultimately, proposed biosensor was introduced to real human serum samples to determine HSP70 sensitively and accurately.
Asunto(s)
Técnicas Biosensibles/métodos , Carcinoma/sangre , Detección Precoz del Cáncer/métodos , Oro/química , Proteínas HSP70 de Choque Térmico/sangre , Nanopartículas del Metal/química , Compuestos de Estaño/química , Anticuerpos Inmovilizados/química , Técnicas Biosensibles/economía , Carcinoma/diagnóstico , Espectroscopía Dieléctrica/economía , Espectroscopía Dieléctrica/métodos , Detección Precoz del Cáncer/economía , Técnicas Electroquímicas/economía , Técnicas Electroquímicas/métodos , Electrodos , Proteínas HSP70 de Choque Térmico/análisis , Humanos , Inmunoensayo/economía , Inmunoensayo/métodos , Nanopartículas del Metal/ultraestructura , Reproducibilidad de los ResultadosRESUMEN
We have developed a new immunological biosensor for ultrasensitive quantification of human epidermal growth factor receptor-3(HER-3). In order to construct the biosensor, the gold electrode surface was layered with, hexanedithiol, gold nanoparticles, and cysteamine, respectively. Anti-HER-3 antibody was covalently attached to cysteamine by glutaraldehyde and used as a bioreceptor in a biosensor system for the first time by this study. Surface characterization was obtained by means of electrochemical impedance spectroscopy and voltammetry. The proposed biosensor showed a good analytical performance for the detection of HER-3 ranging from 0.2 to 1.4 pg mL(-1). Kramers-Kronig transform was performed on the experimental impedance data. Moreover, in an immunosensor system, the single frequency impedance technique was firstly used for characterization of interaction between HER-3 and anti-HER-3. Finally the presented biosensor was applied to artificial serum samples spiked with HER-3.
