title: Induced circular dichroism of gold in the self-assembled polymeric nanoparticles.
abstract: This study reports that the alkanethiol-capped golds loaded in the self-assembled polymeric nanoparticles exhibit the characteristic induced circular dichroism (ICD) in the near UV absorption region. The core-shell type polymeric nanoparticles composed of poly(y-benzyl L-glutamate) (PBLG) as hydrophobic inner core and poly(ethylene oxide) (PEO) as hydrophilic outer shell were obtained by the diafiltration method after dissolving PBLG/PEO block copolymer in organic solvent. The circular dichroism (CD) of alkanethiol-capped gold nanoparticles as the guest was induced by the chiral PBLG as the host in self-assembled polymeric nanoparticles with Cotton effect in the range of 220-230 nm whose crossing point matched lambda(max) in the UV region of alkanethiol-capped gold nanoparticles. Transmission electron microscopy and electrophoretic light scattering spectrophotometry were used to study the morphology and particle size of gold-loaded core-shell type polymeric nanoparticles, respectively. The results indicated that the PBLG chains in the block copolymer and alkanethiol-capped gold nanoparticles were associated together by hydrophobic interaction and chiral PBLG core in the self-assembled polymeric nanoparticles induced CD of the gold.
authors.affiliation: School of Agricultural Biotechnology, Seoul National University, Seoul 151-921, Korea.
authors.forename: Mi-Kyong
authors.initials: MK
authors.lastname: Yoo
authors.forename: Min-Yim
authors.initials: MY
authors.lastname: Park
authors.forename: Sang-Wha
authors.initials: SW
authors.lastname: Lee
authors.forename: Yun-Jaie
authors.initials: YJ
authors.lastname: Choi
authors.forename: In-Kyu
authors.initials: IK
authors.lastname: Park
authors.forename: Chong-Su
authors.initials: CS
authors.lastname: Cho