欢迎参加周二9月26日下午2:00 的学术报告   （新加坡国立大学 徐清华 教授）

报告题目：Plasmon Enhanced Nonlinear Optical Properties for Biomedical Applications

报告人：Qing-Hua Xu (徐清华), Department of Chemistry, National University of Singapore

报告时间：2017年9月26日下午2:00  

报告地点：三楼会议室314

欢迎老师同学参加！

报告摘要

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.