Plasmonic Gold Nanoparticles: Size- and Shape-Controlled Synthesis and Prospective Applications
Abstract: The size- and shape-dependent optical properties of gold nanoparticles make them promising candidate for numerous applications. Upon interaction with resonant electromagnetic radiations, the coherent collective oscillations of free electrons induce large surface electric fields that markedly enhance the radiative properties of gold nanoparticles. The intense scattering and absorption is promising for applications such as cell imaging and cancer therapy. Another important applications is the surface enhanced Raman scattering (SERS), which is an ultra-sensitive technique for the trace detection of materials such as biomolecules, drugs, environmental pollutants, explosives etc. The amplification of the Raman signal is achieved through the enhancement of the electromagnetic field near nanoparticle surface due to the excitation of localized surface plasmons. Both optical properties and field enhancement are very sensitive to the morphology of nanoparticles. Therefore, there is great interest in developing strategies for size- and shape-controlled synthesis of gold nanoparticles. I will discuss a facile wet-chemical protocol that can be used to synthesize gold nanoparticles of various shapes such as nanospheres, nanorods, nanoworms, nanoflowers, nanostars etc. The plasmon band of these nanoparticles can be tuned over a wide range in the visible and near infrared region. I will further discuss some prospective application of gold nanoparticles, especially SERS.
Reminder: Tea and cookies will be in the seminar room before the seminar.