Decorating carbon nanotubes with polyethylene glycol-coated magnetic nanoparticles for implementing highly sensitive enzyme biosensors

Superparamagnetic Fe3O4 nanoparticles were coated with (3-aminopropyl)triethoxysilane and further branched with monomethoxypolyethylene glycol chains. These nanoparticles were employed for the non-covalent surface modification of single walled carbon nanotubes, conferring them magnetic properties. T...

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Bibliographic Details
Published in:Journal of materials chemistry 2011-01, Vol.21 (34), p.12858-12864
Main Authors: Villalonga, Reynaldo, Villalonga, María L., Díez, Paula, Pingarrón, José M.
Format: Article
Language:English
Subjects:
Biosensors
Carbon nanotubes
Enzymes
Nanocomposites
Nanomaterials
Nanoparticles
Nanostructure
Xanthines
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Summary:Superparamagnetic Fe3O4 nanoparticles were coated with (3-aminopropyl)triethoxysilane and further branched with monomethoxypolyethylene glycol chains. These nanoparticles were employed for the non-covalent surface modification of single walled carbon nanotubes, conferring them magnetic properties. This nanomaterial was employed to immobilize the enzyme xanthine oxidase in order to construct magnetically modified disposable gold screen-printed electrodes as bioelectrodes for the determination of xanthine. The electroanalytical properties of the biosensor were modulated by the nanomaterial composition, being optimal at a carbon nanotubes : magnetic nanoparticles ratio of 1 : 27. The resulting biosensor showed a linear dependence on the xanthine concentration in the 0.25-3.5 [small mu ]M range with a fast amperometric response in 12 s. The biosensor also showed a noticeable high sensitivity of 1.31 A M-1 cm-2 and a very low detection limit of 60 nM, which can be compared advantageously with other biosensor designs for xanthine.
ISSN:0959-9428
1364-5501
DOI:10.1039/c1jm11953b