English   español  
Por favor, use este identificador para citar o enlazar a este item: http://hdl.handle.net/10261/126676
logo share SHARE logo core CORE   Add this article to your Mendeley library MendeleyBASE

Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:

Electrostatic and hydrophobic interactions involved in CNT biofunctionalization with short ss-DNA

AutorCarot, M. Lucrecia; Esplandiú, María J. ; Giacomelli, Carla E.
Fecha de publicación2010
EditorAmerican Chemical Society
CitaciónJournal of Physical Chemistry C 114(10): 4459-4465 (2010)
ResumenThis work is aimed at studying the adsorption mechanism of short chain 20-mer pyrimidinic homoss-DNA (oligodeoxyribonucleotide, ODN: polyC20 and polyT20) onto CNT by reflectometry. To analyze the experimental data, the effective-medium theory using the Bruggemann approximation represents a suitable optical model to account for the surface properties (roughness, thickness, and optical constants) and the size of the adsorbate. Systematic information about the involved interactions is obtained by changing the physicochemical properties of the system. Hydrophobic and electrostatic interactions are evaluated by comparing the adsorption on hydrophobic CNT and on hydrophilic silica and by modulating the ionic strength with and without Mg2+. The ODN adsorption process on CNT is driven by hydrophobic interactions only when the electrostatic repulsion is suppressed. The adsorption mode results in ODN molecules in a side-on orientation with the bases (nonpolar region) toward the surface. This unfavorable orientation is partially reverse by adding Mg2+. On the other hand, the adsorption on silica is dominated by the strong repulsive electrostatic interaction that is screened at high ionic strength or mediated by Mg2+. The cation-mediated process induces the interaction of the phosphate backbone (polar region) with the surface, leaving the bases free for hybridization. Although the general adsorption behavior of the pyrimidine bases is the same, polyC20 presents higher affinity for the CNT surface due to its acid-base properties.
Identificadoresdoi: 10.1021/jp9085359
issn: 1932-7447
e-issn: 1932-7455
Aparece en las colecciones: (CIN2) Artículos
Ficheros en este ítem:
Fichero Descripción Tamaño Formato  
accesoRestringido.pdf15,38 kBAdobe PDFVista previa
Mostrar el registro completo

Artículos relacionados:

NOTA: Los ítems de Digital.CSIC están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.