Publicação
Controlled adsorption of cytochrome c to nanostructured gold surfaces
| dc.contributor.author | Gomes, Inês | |
| dc.contributor.author | Feio, Maria J. | |
| dc.contributor.author | Santos, Nuno C. | |
| dc.contributor.author | Eaton, Peter | |
| dc.contributor.author | Serro, Ana Paula | |
| dc.contributor.author | Saramago, Benilde | |
| dc.contributor.author | Pereira, Eulália | |
| dc.contributor.author | Franco, Ricardo | |
| dc.date.accessioned | 2014-03-21T10:58:14Z | |
| dc.date.available | 2014-03-21T10:58:14Z | |
| dc.date.issued | 2012 | |
| dc.description | © Springer Science+Business Media Dordrecht 2012 | eng |
| dc.description.abstract | Controlled electrostatic physisorption of horse heart cytochrome c (Cyt c) onto nanostructured gold surfaces was investigated using Quartz-Crystal Microbalance measurements in planar gold surfaces with or without functionalization using a self-assembled monolayer (SAM) of the alkanethiol mercaptoundecanoic acid (MUA). MUA is a useful functionalization ligand for gold surfaces, shedding adsorbed biomolecules from the excessive electron density of the metal. A parallel analysis was conducted in the corresponding curved surfaces of 15nm gold nanoparticles (AuNPs), using zeta-potential and UV– visible spectroscopy. Atomic Force Microscopy of both types of functionalized gold surfaces with a MUA SAM, allowed for visualization of Cyt c deposits on the nanostructured gold surface. The amount of Cyt c adsorbed onto the gold surface could be controlled by the solution pH. For the assays conducted at pH 4.5, when MUA SAM-functionalized planar gold surfaces are positive or neutral, and Cyt c has a positive net charge, only 13% of the planar gold surface area was coated with protein. In contrast, at pH 7.4, when MUA SAM-functionalized planar gold surfaces and Cyt c have opposite charges, a protein coverage of 28% could be observed implying an adsorption process strongly governed by electrostatic forces. Cyt c adsorption on planar and curved gold surfaces are found to be greatly favored by the presence of a MUA-capping layer. In particular, on the AuNPs, the binding constant is three times larger than the binding constant obtained for the original citrate-capped AuNPs. | eng |
| dc.description.sponsorship | Financial support was provided by Fundação para a Ciência e a Tecnologia (FCT/MEC), Portugal, under Grants PEst-C/EQB/LA0006/2011 to MJF, PE, EP, and RF; and PTDC/CTM-NAN/112241/2009 to RF; and PEst-OE/QUI/UI0100/2011 to APS and BS. IG is a recipient of a FCT/MEC post-doctoral fellowship (SFRH/BPD/63850/2009). | eng |
| dc.identifier.citation | J Nanopart Res (2012) 14:1321 | por |
| dc.identifier.issn | 1388-0764 | |
| dc.identifier.uri | http://dx.doi.org/10.1007/s11051-012-1321-7 | |
| dc.identifier.uri | http://hdl.handle.net/10451/10762 | |
| dc.language.iso | eng | por |
| dc.peerreviewed | yes | por |
| dc.publisher | Springer | por |
| dc.relation.publisherversion | The definitive version is available at http://link.springer.com/ | eng |
| dc.subject | Self-assembled monolayers | eng |
| dc.subject | Alkanethiols | eng |
| dc.subject | Gold surfaces | eng |
| dc.subject | Gold nanoparticles | eng |
| dc.subject | Cytochrome c | eng |
| dc.subject | Quartz crystal microbalance | eng |
| dc.title | Controlled adsorption of cytochrome c to nanostructured gold surfaces | eng |
| dc.type | journal article | |
| dspace.entity.type | Publication | |
| oaire.citation.endPage | 1332 | por |
| oaire.citation.startPage | 1321 | por |
| oaire.citation.title | Journal of Nanoparticle Research | eng |
| oaire.citation.volume | 14 | por |
| rcaap.rights | closedAccess | por |
| rcaap.type | article | por |