When: July 22, 12:00
Where: Skoltech, MR-426 (Blue building)
Seminar:
Boosting analytical properties of plasmonic spiked particles
Prof. Ramon A. Alvarez-Puebla
ICREA, Passeig Lluís Companys 23, 08010 Barcelona, Spain.
Departamento de Quimica Fisica e Inorganica; Universitat Rovira i Virgili, Tarragona, Spain
Abstract:
The anisotropy in the particle geometry determines the field distribution of the plasmon modes in the nanostructure. Upon excitation with light of the appropriate energy, these structures can sustain large electromagnetic fields at ends (nanorods), vertices (triangles), or tip apexes (nanostars), Such field localization can be readily exploited for SERS and thus, for the fabrication of ultrasensitive devices. The intrinsic optical properties of nanostars were theoretically demonstrated by Nordlander and co-workers,5 indicating that the plasmon modes of a nanostar result from the hybridization of the individual plasmons of the core and the tips. The core would serve as a nanoscale antenna, dramatically increasing the excitation cross-section and the electromagnetic field enhancements of the tip plasmons. Recently, the efficiency of gold nanostars for SERS was as well experimentally evidenced. Here we discuss the advantages of using different spiked particles for photonic and sensing applications including distant excitation, direct sensing and bioimaging through the use of encoded particles.
BIO:
Ramón Álvarez Puebla is an ICREA Research Professor at the Universitat Rovira i Virgili in Tarragona. He studied Chemistry at the Universidad de Navarra and got his PhD from the Universidad Pública de Navarra in Surface Science. In 2004 he joined the group of Ricardo Aroca at the University of Windsor (Canada) where he remained in a cross appointment with the General Motors Research and Development center until the end of 2005. In 2006, Dr Álvarez was promoted to Research Officer at the National Center for Nanotechnology (NINT) belonging to the National Research Council of Canada. In 2008 he moved to Spain at the Universidad de Vigo, Spain. He joined ICREA in October of 2012. He is an expert in surface science and spectroscopy with emphasis on the fabrication and characterization of plasmonic particles and their integration into advanced “all optical” sensing devices for biomedicine, chemical biology and environmental monitoring. Currently he is interested in the design and development of plasmonic functional materials and their integration into real live “all optical” sensors.