Science and Education Publishing Nanoscience and Nanotechnology Research 2372-4676 4 1 2017 1 14 Control of the Surface Plasmon Resonance of Two Configurations of Nanoparticles: Simple Gold Nanorod and Gold/Silica Core/Shell 1 6 EN A Sambou P. D. Tall Kh Talla O. Sakho B D Ngom 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 A C Beye NNR2017411 10.12691/nnr-4-1-1 2016 8 16 2016 11 12 2017 1 12 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.