Chitosan/AuNPs Modified Graphene Electrochemical Sensor for Label-Free Human Chorionic Gonadotropin Detection

A new immunosensor is presented for human chorionic gonadotropin (hCG), made by electrodepositing chitosan/gold-nanoparticles over graphene screen-printed electrode (SPE). The antibody was covalently bound to CS via its Fc-terminal. The assembly was controlled by electrochemical Impedance Spectrosco...

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Detalhes bibliográficos
Autor principal: Teixeira, Sofia (author)
Outros Autores: Ferreira, Nádia S. (author), Conlan, Robert S. (author), Guy, O. J. (author), Sales, M. Goreti F. (author)
Formato: article
Idioma:eng
Publicado em: 2015
Assuntos:
Texto completo:http://hdl.handle.net/10400.22/6701
País:Portugal
Oai:oai:recipp.ipp.pt:10400.22/6701
Descrição
Resumo:A new immunosensor is presented for human chorionic gonadotropin (hCG), made by electrodepositing chitosan/gold-nanoparticles over graphene screen-printed electrode (SPE). The antibody was covalently bound to CS via its Fc-terminal. The assembly was controlled by electrochemical Impedance Spectroscopy (EIS) and followed by Fourier Transformed Infrared (FTIR). The hCG-immunosensor displayed linear response against the logarithm-hCG concentration for 0.1–25 ng/mL with limit of detection of 0.016 ng/mL. High selectivity was observed in blank urine and successful detection of hCG was also achieved in spiked samples of real urine from pregnant woman. The immunosensor showed good detection capability, simplicity of fabrication, low-cost, high sensitivity and selectivity.