This article presents an investigative study of the photothermal effect of various compound nanoparticles (attaching the several small nanoparticles to a large nanoparticle by linkers). Initially, some compound nanoparticles such as Au-Au nanoparticles were fabricated and the effective medium electrical conductivities, found to vary greatly in gradient with variations in temperature, were analyzed using a nanolens - based approach. A nano-lens forms when Au-Au nanoparticles interact with electromagnetic waves. More precisely, the interaction of larger nanoparticles with an incident light generates a high intensity plasmonic field around it, and the dramatic effect of this near-field on small nanoparticles leads to the creation of a nano-lens. The modeled and experimental results obtained in this study showed that the Plasmon-plasmon interaction, which leads to the formation of a nano-lens with Au-Au nanoparticles, strongly influenced the medium electrical conductivity which is a vital key for detection of cancer cells. The gradient of electrical conductivity correlated directly with the amount of localized heat generation by Au-Au nanoparticles, offering means by which the temperature could be inferred. The amount of heat generated depended on both the number of nanoparticles present and the effectiveness with which they interacted, particularly in such a high intensity nano-lens. (C) 2016 Elsevier B.V. All rights reserved.