报告人：徐清华 新加坡国立大学化学系
地点： 教十二-201
时间：11月4日，周五，15:00-16:00
摘要：
Noble metal nanoparticles, such as gold (Au) and silver (Ag), display unique properties known as localized surface Plasmon resonance, which could be utilized to enhance linear and nonlinear optical properties of nearby chromophores and metal nanoparticles themselves. In this talk, I will present our group’s efforts on plasmon enhanced one- and two-photon excitation fluorescence and their applications. In particular, we found an interesting phenomenon that originally nonfluorescent metal nanoparticles emit strong two-photon photoluminescence (2PPL) upon plasmon coupling in the aggregated state. We have demonstrated that this kind of plasmon coupling enhanced 2PPL is a general phenomenon for Au and Ag nanoparticles of different morphologies.
2PPL of these metal nanoparticles was found enhanced by >800-fold in the colloid solution and five orders of magnitude on single particle level upon plasmon coupling. As many biologically important species can cause aggregation of metal nanoparticles, this phenomenon has been further utilized to develop various two-photon sensing and imaging applications to take their unique advantages of deep penetration into biological tissues and 3-dimensional confined excitation. We have also employed ultrafast spectroscopy and single particle spectroscopy to understand the underlying enhancement mechanisms.
个人简介：
徐清华于1993年获得浙江大学学士学位，1996年获得北京大学硕士学位后赴美留学，1997、2001年先后于美国芝加哥大学和加州大学伯克利分校获硕士与博士学位，2001-2002、2002-2005年先后在美国斯坦福大学和加州大学圣塔芭芭拉分校从事博士后研究。2005年加入新加坡国立大学化学系并于2011年获终身教职。研究兴趣主要集中于金属纳米和共轭高分子等低维及薄膜材料的各种非线系光学和电子学性质，动力学基本过程及机理，并进一步开发这些材料在光催化，生物成像，生物传感检测及光动力癌症治疗等方面的应用。在SCI检索的学术杂志上发表学术论文140余篇，H因子40。
