Charge-induced plasmonic shifts in extinction spectra of gold nanostructures

Recently, the phenomenon of Surface Plasmon Resonance (SPR) has been investigated extensively especially due to its promising potential in the field of biosensing. SPR has applications in SPR based biosensor which can precisely detect the attachment of specific type of biomolecules to glass surface, for example to detect determine antibody-antigen interactions and to identify hormones. It can also be used in building photovoltaic solar cells and has other applications in the field of metamaterials. To enable these applications, an understanding of the optically effects of charging on nanostructures and the influence of size and shape are essential. [1] In this report, gold nanostructures of various shape and size were simulated using finite-difference-time-domain method and extinction cross-section were calculated and compared for different nanostructure shape as well as varying level of free electron density introduced by charging. The simulation results were compared with theoretical predications and recommendations on future works were suggested.Bachelor of Engineering (Materials Engineering