4. Introduction to Light–Particle Interactions

In the previous chapter, we introduced targeted photothermal therapy of cancer, which combines molecular targeting mechanisms with the unique light absorption properties of nanoparticles to deliver heat and treat diseases at a subcellular level. To understand how photothermal therapies like nanophotothermolysis and nanophotohyperthermia could be useful, it is important to understand how radiation interacts with nanoparticles. This chapter models the light absorption properties of nanoparticles in the X-ray, optical, and RF ranges of the spectrum. To find the optimal wavelength of radiation and optimal size range of nanoparticles for effective heating/activating of the nanoparticles, we use an extended Lorentz–Mie diffraction theory, taking into account the plasmon-resonance absorption effect observed in metal nanoparticles. This chapter contains material adapted from our publications listed at the end of the chapter. The detailed list of references and reviews on a given topic of this chapter can be found in those original papers.