A functionalized nanoparticle, having a core, optionally having a shell on at least a portion thereof, wherein the core contains a material that can convert applied X-ray energy into emitted UV energy and wherein the shell, when present, contains a plasmonics active material wherein the nanoparticle has on a surface thereof at least one psoralen compound capable of activation by the emitted UV energy, and the use of the functionalized nanoparticle in a method of treating a cell proliferation disorder such as cancer.
