Plasmonic Response of Gold Nanoparticles Arrays Made by Nanosphere Lithography and Electron Beam Lithography

Metallic nanoparticles in the 10-100 nm size range exhibit a very specific optical response in the visible spectrum. Here we present our work towards possible applications of such particles for the design of highly sensitive and miniaturized biosensors. Fabrication of nanoparticles is discussed, comprising hexagonal arrays of truncated tetrahedrons made by nanosphere lithography (NSL), and nanoparticles of different shapes made by electron beam lithography. The specific properties of both types of nanoparticles are discussed. From an experimental point of view, characterization is made using dark field spectroscopy, together with SEM or AFM imaging. To give more insight in the behavior of individual particles and arrays of particles, the discrete dipole approximation appears to be one of the most successful modeling techniques. We conclude with a discussion of the use of this method to model our particles and compare the results with experimental measurements and other common modeling techniques.