Department of Chemistry, National University of Singapore, 3 Science Drive 3, Republic of Singapore 117543.
Langmuir. 2010 Dec 7;26(23):18020-3. doi: 10.1021/la103668k. Epub 2010 Oct 28.
Interactions between noble metal (Ag and Au) nanoparticles and conjugated polymers as well as their one- and two-photon emission have been investigated. Ag and Au nanoparticles exhibited extraordinary quenching effects on the fluorescence of cationic poly(fluorinephenylene). The quenching efficiency by 37-nm Ag nanoparticles is ∼19 times more efficient than that by 13-nm Au nanoparticles, and 9-10 orders of magnitude more efficient than typical small molecule dye-quencher pairs. On the other hand, the cationic conjugated polymers induce the aggregate formation and plasmonic coupling of the metal nanoparticles, as evidenced by transmission electron microscopy images and appearance of a new longitudinal plasmon band in the near-infrared region. The two-photon emissions of Ag and Au nanoparticles were found to be significantly enhanced upon addition of conjugated polymers, by a factor of 51-times and 9-times compared to the isolated nanoparticles for Ag and Au, respectively. These studies could be further extended to the applications of two-photon imaging and sensing of the analytes that can induce formation of metal nanoparticle aggregates, which have many advantages over the conventional one-photon counterparts.
研究了贵金属（Ag 和 Au）纳米粒子与共轭聚合物之间的相互作用及其单光子和双光子发射。Ag 和 Au 纳米粒子对阳离子聚（芴）的荧光表现出非凡的猝灭效应。37nm Ag 纳米粒子的猝灭效率比 13nm Au 纳米粒子高约 19 倍，比典型的小分子染料猝灭剂对高 9-10 个数量级。另一方面，阳离子共轭聚合物诱导金属纳米粒子的聚集和等离子体耦合，这可以通过透射电子显微镜图像和在近红外区域出现新的纵向等离子体带得到证明。研究发现，加入共轭聚合物后，Ag 和 Au 纳米粒子的双光子发射显著增强，与孤立的纳米粒子相比，Ag 和 Au 的增强因子分别为 51 倍和 9 倍。这些研究可以进一步扩展到双光子成像和对可以诱导金属纳米粒子聚集形成的分析物的传感应用，这比传统的单光子对应物具有许多优势。
