English   español  
Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/31286
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:


Nanomechanics of the Formation of DNA Self-Assembled Monolayers and Hybridization on Microcantilevers

AuthorsÁlvarez, Mar ; Carrascosa, Laura G. ; Moreno, M. ; Calle Martín, Ana ; Zaballos, Ángel; Lechuga, Laura M. ; Martínez-Alonso, Carlos; Tamayo de Miguel, Francisco Javier
Issue Date28-Sep-2004
PublisherAmerican Chemical Society
CitationLangmuir 20(22): 9663-9668 (2004)
AbstractBiomolecular interactions over the surface of a microcantilever can produce its bending motion via changes of the surface stress, which is referred to nanomechanical response. Here, we have studied the interaction forces responsible for the bending motion during the formation of a self-assembled monolayer of thiolated 27-mer single-stranded DNA on the gold-coated side of a microcantilever and during the subsequent hybridization with the complementary nucleic acid. The immobilization of the single-stranded DNA probe gives a mean surface stress of 25 mN/m and a mean bending of 23 nm for microcantilevers with a length and thickness of about 200 μm and 0.8 μm, respectively. The hybridization with the complementary sequence could not be inferred from the nanomechanical response. The nanomechanical response was compared with data from well-established techniques such as surface plasmon resonance and radiolabeling, to determine the surface coverage and study the intermolecular forces between neighboring DNA molecules anchored to the microcantilever surface. From both techniques, an immobilization surface density of 3 × 1012 molecules/cm2 and a hybridization efficiency of 40% were determined. More importantly, label-free hybridization was clearly detected in the same conditions with a conventional sensor based on surface plasmon resonance. The results imply that the nanomechanical signal during the immobilization process arises mainly from the covalent attachment to the gold surface, and the interchain interactions between neighboring DNA molecules are weak, producing an undetectable surface stress. We conclude that detection of nucleic acid hybridization with nanomechanical sensors requires reference cantilevers to remove nonspecific signals, more sensitive microcantilever geometries, and immobilization chemistries specially addressed to enhance the surface stress variations.
Description6 páginas, 6 figuras.
Publisher version (URL)http://dx.doi.org/10.1021/la0489559
Appears in Collections:(IMN-CNM) Artículos
(CNB) Artículos
Files in This Item:
File Description SizeFormat 
la0489559.pdf105,74 kBAdobe PDFThumbnail
Show full item record
Review this work

Related articles:

WARNING: Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.