Glucose biosensor from covalent immobilization of chitosan-coupled carbon nanotubes on polyaniline-modified gold electrode.
ACS Appl Mater Interfaces
; 2(11): 3083-91, 2010 Nov.
Article
em En
| MEDLINE
| ID: mdl-20964413
ABSTRACT
An amperometric glucose biosensor was prepared using polyaniline (PANI) and chitosan-coupled carbon nanotubes (CS-CNTs) as the signal amplifiers and glucose oxidase (GOD) as the glucose detector on a gold electrode (the Au-g-PANI-c-(CS-CNTs)-GOD biosensor). The PANI layer was prepared via oxidative graft polymerization of aniline from the gold electrode surface premodified by self-assembled monolayer of 4-aminothiophenol. CS-CNTs were covalently coupled to the PANI-modified gold substrate using glutaradehyde as a bifunctional linker. GOD was then covalently bonded to the pendant hydroxyl groups of chitosan using 1,4-carbonyldiimidazole as the bifunctional linker. The surface functionalization processes were ascertained by X-ray photoelectron spectroscopy (XPS) analyses. The field emission scanning electron microscopy (FESEM) images of the Au-g-PANI-c-(CS-CNTs) electrode revealed the formation of a three-dimensional surface network structure. The electrode could thus provide a more spatially biocompatible microenvironment to enhance the amount and biocatalytic activity of the immobilized enzyme and to better mediate the electron transfer. The resulting Au-g-PANI-c-(CS-CNTs)-GOD biosensor exhibited a linear response to glucose in the concentration range of 1-20 mM, good sensitivity (21 µA/(mM·cm(2))), good reproducibility, and retention of >80% of the initial response current after 2 months of storage.
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Técnicas Biossensoriais
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Nanotubos de Carbono
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Quitosana
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Enzimas Imobilizadas
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Glucose
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Ouro
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Compostos de Anilina
Idioma:
En
Ano de publicação:
2010
Tipo de documento:
Article