title: Controlled dispersion of silver nanoparticles into the bulk of thermosensitive polymer microspheres: tunable plasmonic coupling by temperature detected by surface enhanced Raman scattering.
abstract: By in situ reduction of Ag(+) ions pre-dispersed inside thermosensitive microspheres of poly[(N-isopropylacrylamide)-co-(methacrylic acid)] (P(NIPAM-co-MAA)), a 3D copolymer-supported network of silver nanoparticles is created and extensively characterized by surface-enhanced Raman scattering (SERS). The effective dispersion and the suitable density of the silver nanoparticles in the composite microspheres are demonstrated by the thermal-induced SERS signal and its high reproducibility during thermocycling. When the temperature of the system increases above 32 °C, spatial separation of the silver nanoparticles decreases and the numbers of Ag nanoparticles and P(NIPAM-co-MAA) microspheres under illumination spot increase as a result of the shrinkage of the P(NIPAM-co-MAA) chains, leading to the ramp of the SERS effect. By means of the high reversibility of the thermosensitive phase transition of the P(NIPAM-co-MAA) microspheres, SERS activity of the silver nanoparticle network embedded in the microsphere can be well controlled by thermal-induced variation of special separation.
authors: School of Chemistry and Environment, Beijing University of Aeronautics and Astronautics, Beijing, 100191, China. pgyin@buaa.edu.cn
authors: Peng-Gang
authors: PG
authors: Yin
authors: Ying
authors: Y
authors: Chen
authors: Li
authors: L
authors: Jiang
authors: Ting-Ting
authors: TT
authors: You
authors: Xian-Yong
authors: XY
authors: Lu
authors: Lin
authors: L
authors: Guo
authors: Shihe
authors: S
authors: Yang