Penicillin biosensor based on a capacitive field-effect structure functionalized with a dendrimer/carbon nanotube multilayer.
Biosens Bioelectron
; 25(2): 497-501, 2009 Oct 15.
Article
em En
| MEDLINE
| ID: mdl-19651505
Silicon-based sensors incorporating biomolecules are advantageous for processing and possible biological recognition in a small, reliable and rugged manufactured device. In this study, we report on the functionalization of field-effect (bio-)chemical sensors with layer-by-layer (LbL) films containing single-walled carbon nanotubes (SWNTs) and polyamidoamine (PAMAM) dendrimers. A capacitive electrolyte-insulator-semiconductor (EIS) structure modified with carbon nanotubes (EIS-NT) was built, which could be used as a penicillin biosensor. From atomic force microscopy (AFM) and field-emission scanning electron microscopy (FESEM) images, the LbL films were shown to be highly porous due to interpenetration of SWNTs into the dendrimer layers. Capacitance-voltage (C/V) measurements pointed to a high pH sensitivity of ca. 55 mV/pH for the EIS-NT structures. The biosensing ability towards penicillin of an EIS-NT-penicillinase biosensor was also observed as the flat-band voltage shifted to lower potentials at different penicillin concentrations. A dynamic response of penicillin concentrations, ranging from 5.0 microM to 25 mM, was evaluated for an EIS-NT with the penicillinase enzyme immobilized onto the surfaces, via constant-capacitance (ConCap) measurements, achieving a sensitivity of ca. 116 mV/decade. The presence of the nanostructured PAMAM/SWNT LbL film led to sensors with higher sensitivity and better performance.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Penicilinas
/
Técnicas Biossensoriais
/
Nanotecnologia
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Nanotubos de Carbono
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Eletroquímica
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Dendrímeros
Idioma:
En
Revista:
Biosens Bioelectron
Assunto da revista:
BIOTECNOLOGIA
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Reino Unido