Edge promoted ultrasensitive electrochemical detection of organic bio-molecules on epitaxial graphene nanowalls.
Biosens Bioelectron
; 70: 137-44, 2015 Aug 15.
Article
em En
| MEDLINE
| ID: mdl-25801954
ABSTRACT
We report the simultaneous electrochemical detection of dopamine (DA), uric acid (UA) and ascorbic acid (AA) on three dimensional (3D) unmodified 'as-grown' epitaxial graphene nanowall arrays (EGNWs). The 3D few layer EGNWs, unlike the 2D planar graphene, offers an abundance of vertically oriented nano-graphitic-edges that exhibit fast electron-transfer kinetics and high electroactive surface area to geometrical area (EAA/GA≈134%), as evident from the Fe(CN)6(3-/4-) redox kinetic study. The hexagonal sp(2)-C domains, on the basal plane of the EGNWs, facilitate efficient adsorption via spontaneous π-π interaction with the aromatic rings in DA and UA. Such affinity together with the fast electron kinetics enables simultaneous and unambiguous identification of individual AA, DA and UA from their mixture. The unique edge dominant EGNWs result in an unprecedented low limit of detection (experimental) of 0.033 nM and highest sensitivity of 476.2 µA/µM/cm(2), for UA, which are orders of magnitude higher than comparable existing reports. A reaction kinetics based modeling of the edge-oriented 3D EGNW system is proposed to illustrate the superior electro-activity for bio-sensing applications.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Compostos Orgânicos
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Biopolímeros
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Imunoensaio
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Condutometria
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Nanopartículas
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Grafite
Tipo de estudo:
Diagnostic_studies
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Prognostic_studies
Idioma:
En
Revista:
Biosens Bioelectron
Assunto da revista:
BIOTECNOLOGIA
Ano de publicação:
2015
Tipo de documento:
Article
País de afiliação:
Taiwan