title: Highly Sensitive Detection of Organic Molecules on the Basis of a Poly(N-isopropylacrylamide) Microassembly Formed by Plasmonic Optical Trapping.
abstract: We demonstrate that a poly(N-isopropylacrylamide) (PNIPAM) microassembly, formed by plasmonic optical trapping, can provide the platform for a highly sensitive detection technique for fluorescent and nonfluorescent organic molecules dissolved in aqueous solution. PNIPAM microassemblies can be easily formed by a combination with a photothermal effect and an enhanced optical force. These physical phenomena were obtained through resonant excitation of localized surface plasmon (LSP). Sparsely distributed fluorescent or nonfluorescent molecules dissolved in solution can be extracted into the PNIPAM assembly, resulting in an increase in fluorescence or Raman signals. In particular, we successfully detected quite small amounts of analytes (rhodamine B) at the 10-9mol/L level. Using LSP is an alternative approach in analytical chemistry and can be used in addition to surface enhanced Raman scattering and surface enhanced fluorescence.
authors.affiliation: Division of Molecular Materials Science, Graduate School of Science, Osaka City University , 3-3-138 Sugimoto, Sumiyoshi, Osaka 558-8585, Japan.
authors.forename: Tatsuya
authors.identifier: 0000-0001-7213-6466
authors.initials: T
authors.lastname: Shoji
authors.affiliation: Division of Molecular Materials Science, Graduate School of Science, Osaka City University , 3-3-138 Sugimoto, Sumiyoshi, Osaka 558-8585, Japan.
authors.forename: Daiki
authors.initials: D
authors.lastname: Sugo
authors.affiliation: Graduate School of Chemical Sciences and Engineering, Hokkaido University , Sapporo 060-0810, Japan.
authors.forename: Fumika
authors.initials: F
authors.lastname: Nagasawa
authors.affiliation: Graduate School of Chemical Sciences and Engineering, Hokkaido University , Sapporo 060-0810, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Murakoshi
authors.affiliation: Graduate School of Chemical Sciences and Engineering, Hokkaido University , Sapporo 060-0810, Japan.
authors.forename: Noboru
authors.initials: N
authors.lastname: Kitamura
authors.affiliation: Division of Molecular Materials Science, Graduate School of Science, Osaka City University , 3-3-138 Sugimoto, Sumiyoshi, Osaka 558-8585, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Tsuboi