title: Preparation of near-infrared light absorbing gold nanoparticles using polyethylene glycol-attached dendrimers.
abstract: The photochemical properties of gold nanoparticles (Au NPs) are largely influenced by their size and morphology. Stably dispersed Au NPs that absorb near-infrared (NIR) light are useful for biomedical applications. We prepared well-dispersed NIR-absorbing Au NPs using seeding growth from Au NPs encapsulated in polyethylene glycol (PEG)-attached dendrimers. Formaldehyde was used as a reductant to prepare gold nanoparticles with convex-concave surfaces. Low pH and an appropriate amount of gold ion were required to prepare Au NPs that absorbed NIR-light. Interestingly, the encapsulation of Au NPs within the PEGylated dendrimers was important for preparation of NIR-absorbing Au NPs. Transmission electron microscope (TEM) analysis showed that these Au NPs had convex-concave surfaces and large diameters. This paper presents a novel preparation method for NIR-responsive Au NPs by reduction with formaldehyde.
authors.affiliation: Nanoscience and Nanotechnology Research Center, Research Organization for the 21st Century, Osaka Prefecture University, 1-2 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8570, Japan. c-kojima@21c.osakafu-u.ac.jp
authors.forename: Chie
authors.initials: C
authors.lastname: Kojima
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Umeda
authors.forename: Atsushi
authors.initials: A
authors.lastname: Harada
authors.forename: Kenji
authors.initials: K
authors.lastname: Kono
mesh_terms: D050091:Dendrimers / Q000737:chemistry*; D005557:Formaldehyde / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D007259:Infrared Rays; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D010316:Particle Size; D010777:Photochemistry; D011092:Polyethylene Glycols / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013499:Surface Properties
chemical_list: D050091:Dendrimers; D005557:Formaldehyde; D011092:Polyethylene Glycols; D006046:Gold