title: Preparation of plasmonic vesicles from amphiphilic gold nanocrystals grafted with polymer brushes.
abstract: Gold nanovesicles contain multiple nanocrystals within a polymeric coating. The strong plasmonic coupling between adjacent nanoparticles in their vesicular shell makes ultrasensitive biosensing and bioimaging possible. In our laboratory, multifunctional plasmonic vesicles are assembled from amphiphilic gold nanocrystals (such as gold nanoparticles and gold nanorods) coated with mixed hydrophilic and hydrophobic polymer brushes or amphiphilic diblock co-polymer brushes. To fulfill the different requirements of biomedical applications, different polymers that are either pH=responsive, photoactive or biodegradable can be used to form the hydrophobic brush, while the hydrophilicity is maintained by polyethylene glycol (PEG). This protocol covers the preparation, surface functionalization and self-assembly of amphiphilic gold nanocrystals grafted covalently with polymer brushes. The protocol can be completed within 2 d. The preparation of amphiphilic gold nanocrystals, coated with amphiphilic diblock polymer brushes using a 'grafting to' method or mixed hydrophilic and hydrophobic polymer brushes using tandem 'grafting to' and 'grafting from' methods, is described. We also provide detailed procedures for the preparation and characterization of pH-responsive plasmonic gold nanovesicles from amphiphilic gold nanocrystals using a film-rehydration method that can be completed within ∼3 d.
authors.affiliation: Laboratory of Molecular Imaging and Nanomedicine, National Institute of Biomedical Imaging and Bioengineering (NIBIB), US National Institutes of Health (NIH), Bethesda, Maryland, USA.
authors.forename: Jibin
authors.initials: J
authors.lastname: Song
authors.affiliation: Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, Department of Biomedical Engineering, School of Medicine, Shenzhen University, Shenzhen, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Huang
authors.affiliation: Laboratory of Molecular Imaging and Nanomedicine, National Institute of Biomedical Imaging and Bioengineering (NIBIB), US National Institutes of Health (NIH), Bethesda, Maryland, USA.
authors.forename: Xiaoyuan
authors.identifier: http://orcid.org/0000-0002-9622-0870
authors.initials: X
authors.lastname: Chen
mesh_terms: D006046:Gold / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D053768:Metal Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D011092:Polyethylene Glycols / Q000737:chemistry*; D020349:Surface Plasmon Resonance
chemical_list: D011092:Polyethylene Glycols; D006046:Gold