title: CdSe/AsS core-shell quantum dots: preparation and two-photon fluorescence.
abstract: Arsenic(II) sulfide (AsS)-coated CdSe core-shell nanocrystals can be prepared by a cluster-complex deposition approach under mild conditions. At 60 degrees C, growth of an AsS shell onto a CdSe nanocrystal can be realized through the crystallization of a cluster complex of AsS/butylamine in a mixed solvent of isopropanol/chloroform. The new, type I core-shell nanocrystal exhibits markedly enhanced one-photon fluorescence as well two-photon upconversion fluorescence. The nanocrystals can be used for infrared-excited upconversion cellular labeling.
authors.affiliation: Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore.
authors.forename: Junzhong
authors.initials: J
authors.lastname: Wang
authors.forename: Ming
authors.initials: M
authors.lastname: Lin
authors.forename: Yongli
authors.initials: Y
authors.lastname: Yan
authors.forename: Zhe
authors.initials: Z
authors.lastname: Wang
authors.forename: Paul C
authors.initials: PC
authors.lastname: Ho
authors.forename: Kian Ping
authors.initials: KP
authors.lastname: Loh