title: Effect of PEGylation on controllably spaced adsorption of ferritin molecules.
abstract: The interparticle distance between nanoparticles (NPs) dispersed on on SiO2 was shown to be controlled by PEGylation. Ferritins with nanoparticle cores were prepared and PEGylated with poly(ethylene glycol)s (PEGs) of two different molecular weights. It was shown that the thickness of the PEG layer on the ferritin surface determines the interparticle distance under short Debye lengths. Under conditions where the Debye length was greater than the PEG layer thickness, distance between ferritins increased due to the electrostatic repulsive force. Results suggest that the PEG layer accommodated a small amount of counterions insufficient to cancel the ferritin outer surface charges. Simulation showed that ferritins adsorbed randomly and interparticle distance can be predicted theoretically. We demonstrate that PEGylated ferritins, that is, NP cores, can be dispersed on a surface with interval distances between particles determined by the combination of the ionic strength of the solution and the molecular weight of the PEG.
authors.affiliation: CREST, Japan Science and Technology Agency , 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan.
authors.forename: Rikako
authors.initials: R
authors.lastname: Tsukamoto
authors.forename: Maia
authors.initials: M
authors.lastname: Godonoga
authors.forename: Ryota
authors.initials: R
authors.lastname: Matsuyama
authors.forename: Makoto
authors.initials: M
authors.lastname: Igarashi
authors.forename: Jonathan Gardiner
authors.initials: JG
authors.lastname: Heddle
authors.forename: Seiji
authors.initials: S
authors.lastname: Samukawa
authors.forename: Ichiro
authors.initials: I
authors.lastname: Yamashita
mesh_terms: D000327:Adsorption; D005293:Ferritins / Q000737:chemistry*; D008970:Molecular Weight; D010316:Particle Size; D011100:Polyglycolic Acid / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry; D055672:Static Electricity; D013499:Surface Properties
chemical_list: D011100:Polyglycolic Acid; D012822:Silicon Dioxide; D005293:Ferritins