title: Robust ligand shells for biological applications of gold nanoparticles.
abstract: An important point regarding the development of stable biofunctional nanoparticles for biomedical applications is their potential for aspecific interactions with the molecules of the biological environment. Here we report a new self-assembled ligand monolayer system for gold nanoparticles called Mix-matrices, formed by a mixture of HS-PEG and alcohol peptides (peptidols) molecules. Stability of the Mix-capped nanoparticles prepared in various conditions was assessed using tests of increasing stringency. The results highlight the importance of identifying a concentration of ligands sufficiently high to obtain a compact matrix when preparing nanoparticles and that the stability of capped nanoparticles in biological environments cannot be predicted solely on their resistance to electrolyte-induced aggregation. The Mix-capped nanoparticles are resistant to aggregation induced by electrolytes and to aspecific interactions with proteins and ligand exchange. In addition, Mix-matrices allow the easy introduction of a single recognition function per nanoparticle, allowing the specific and stoichiometric labeling of proteins with gold nanoparticles. Therefore, the Mix-matrices provide a useful tool for the development of nanoparticle-based quantitative bioanalytical and imaging techniques, as well as for therapeutic purposes, such as the specific targeting of cancerous cells for photothermal destruction.
authors.affiliation: Liverpool Institute for Nanoscale Science, Engineering and Technology, School of Biological Sciences, Biosciences Building, Crown Street, University of Liverpool, Liverpool, L69 7ZB, UK. lduchesn@liv.ac.uk
authors.forename: Laurence
authors.initials: L
authors.lastname: Duchesne
authors.forename: Denis
authors.initials: D
authors.lastname: Gentili
authors.forename: Mauro
authors.initials: M
authors.lastname: Comes-Franchini
authors.forename: David G
authors.initials: DG
authors.lastname: Fernig
mesh_terms: D006046:Gold / Q000737:chemistry*; D008024:Ligands; D008567:Membranes, Artificial; D053768:Metal Nanoparticles / Q000737:chemistry*; D009842:Oligopeptides / Q000138:chemical synthesis / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D008024:Ligands; D008567:Membranes, Artificial; D009842:Oligopeptides; D011092:Polyethylene Glycols; D006046:Gold