A nanoparticle comprising a shell surrounding a core material with a lower conductivity than the shell material, wherein the core center is offset in relation to the shell center. A method comprising providing a nanoparticle comprising a nonconductive core and a conductive shell, and asymmetrically depositing additional conductive material on the conductive shell. A method comprising providing a concentric nanoshell having a core and a shell, immobilizing the concentric nanoshell onto a support, and asymmetrically depositing a conductive material onto the shell to produce a nanoegg.