title: Intercalation of bovine serum albumin coated gold clusters between phospholipid bilayers: temperature-dependent behavior of lipid-AuQC@BSA assemblies with red emission and superlattice structure.
abstract: A method has been developed to encapsulate bovine serum albumin (BSA)-coated gold quantum clusters (AuQC@BSA) in a multilamellar system of dipalmitoylphosphatidylcholine (DPPC). Results have shown that intercalation of AuQC@BSA particles into lipid bilayers occurs in the presence of CaCl2. Intense red photoluminescence emission was observed after encapsulation of the clusters. A well-defined structure was found with periodic distances drastically larger than that in the pure DPPC/water system. Although Ca(2+) ions can change the dipole characteristics of the lipid bilayer surface, leading to unbinding between the bilayers of multilamellar DPPC/water system, the repulsion is shielded in the presence of AuQC@BSA particles. A coherent superlattice structure evolves due to mixed Ca(2+)-DPPC and Ca(2+)-AuQC@BSA interactions. Studies at different temperatures have suggested a correlation between the luminescence properties of the clusters and phase transition of the lipid layers. The temperature-dependent behavior assumes the connection between the coating and the lipid bilayer surface. Temperature-dependent features of lipid intercalated Au clusters provide new opportunities in their application.
authors.affiliation: Institute of Molecular Pharmacology, Research Centre for Natural Sciences, Hungarian Academy of Sciences , 2 Magyar tudósok blvd, Budapest 1117, Hungary.
authors.forename: Balázs
authors.initials: B
authors.lastname: Söptei
authors.forename: Judith
authors.initials: J
authors.lastname: Mihály
authors.forename: Júlia
authors.initials: J
authors.lastname: Visy
authors.forename: András
authors.initials: A
authors.lastname: Wacha
authors.forename: Attila
authors.initials: A
authors.lastname: Bóta
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry; D000818:Animals; D002122:Calcium Chloride / Q000737:chemistry; D002417:Cattle; D006046:Gold / Q000737:chemistry*; D007364:Intercalating Agents / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry* / Q000378:metabolism; D044367:Phase Transition; D012710:Serum Albumin, Bovine / Q000737:chemistry* / Q000378:metabolism; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D007364:Intercalating Agents; D008051:Lipid Bilayers; D014867:Water; D015060:1,2-Dipalmitoylphosphatidylcholine; D012710:Serum Albumin, Bovine; D006046:Gold; D002122:Calcium Chloride