eng Science and Education Publishing Nanoscience and Nanotechnology Research 2372-4676 2017-01-14 4 1 1 6 10.12691/nnr-4-1-1 NNR2017411 article A Sambou 1 P. D. Tall 1 Kh Talla 1 O. Sakho B D Ngom bdngom@gmail.com 1 A C Beye 1 Laboratoire de Photonique et de Nano-Fabrication, Faculté des sciences et Techniques Université Cheikh Anta Diop de Dakar (UCAD) B.P. 25114 Dakar-Fann Dakar, Senegal We report on the study of optical properties of ellipsoidal nanoparticles forms using Gans's theory and Drude model; we introduce important parameters such as surrounding medium, shell thickness. Nanorods shaped nanoparticles are distinguished of others forms by the appearance of two peaks corresponding to their plasmonic bands: transverse mode placed in the visible region and the longitudinal mode located toward longer wavelength. The simulation results show a strong dependence of core/shell ratio and surrounding medium on longitudinal resonance. Nano shell nanoparticles composed with a big core (gold) aspect ratio are more shifted with increasing of silica layer. http://pubs.sciepub.com/nnr/4/1/1/nnr-4-1-1.pdf nanorods particles core/shell particles surface plasmon resonance