THE LATEST NEWS ABOUT US, GENERAL AND SPECIFIC OF EACH GROUP
- Nov 28, 2009 Oral on the Workshop on Nanomaterials for Energy and Biotechnology
- Nov 21, 2009 Instability of Cationic Gold Nanoparticle Bioconjugates: The Role of Citrate Ions
- Nov 21, 2009 Oral and Poster on the Workshop on Solid Oxide Fuel Cells: Materials and Technology
- Nov 17, 2009 Amphiphillic Organic Crystals
- Nov 17, 2009 Iodine/Iodide-Free Dye-Sensitized Solar Cells
- Nov 15, 2009 International Advisory Committee at Nanoagri 2010
- Nov 11, 2009 Plenary Speaker at Biosensors 2010
- Nov 10, 2009 Conference: 'La Ciencia inesperada. Historia de los descubrimientos que nadie buscó'
- Nov 07, 2009 Conference: 'Viaje a Nanolandia'
- Nov 04, 2009 Fabrication of large addition energy quantum dots in graphene
- Nov 02, 2009 Conference on NordsForsk spintronics workshop
- Nov 01, 2009 Invited Lecture at CNIC
Nov 21, 2009
Instability of Cationic Gold Nanoparticle Bioconjugates: The Role of Citrate Ions
Isaac Ojea-Jiménez and Victor Puntes, member and leader of the Inorganic Nanoparticles group at CIN2 (ICN-CISC) have published 'Instability of Cationic Gold Nanoparticle Bioconjugates: The Role of Citrate Ions' on the Journal of American Chemical Society.
Gold nanoparticles of 6, 8, and 16 nm, synthesized with HAuCl4 and sodium citrate, were derived with biomolecules based on the peptide CIPGNVG and possessing different terminal charges. We have studied the stability of these conjugates as a function of ionic strength, pH, and the presence of other species in solution. It was observed that multiple electrostatic interactions between the conjugates mediated by cross-linking species led to an effective strong bond and consequently to irreversible aggregation and precipitation. In the presence of citrate or diamine ions, nanoparticles precipitated when two-headed ions had charges opposite (and therefore attractive) to the conjugate, thus acting as bridging molecules. This effect depends on the pH, the concentration of particles, and their size, and it is relevant to designing bioconjugates for biomedical applications.