February 10, 2015
A recent study by the members of MBN Research team, published in Physical Review Letters , aims at revealing physical mechanisms which stand behind the novel techniques of treating tumors. The authors have elucidated the enhancement of the low-energy electron yield from noble metal nanoparticles. The use of such nanoscale systems in cancer treatments with ionizing radiation was proposed recently.
In the paper, a new mechanism of the electron yield enhancement due to the collective electron excitations in noble metal nanoparticles is revealed. This effect is due to the plasmon-type excitations of delocalized valence electrons and also due to the collective excitation of d electrons in individual atoms in a nanoparticle. The collective excitations of the both types stimulate an increase in the emission of low-energy electrons which are important agents of biodamage. The authors have demonstrated that the number of the electrons generated by the gold, platinum, and silver nanoparticles significantly exceeds that produced by water medium. This observation endorses the application of the nanoparticles in cancer therapy with ionizing radiation.
 Alexey Verkhovtsev, Andrei V. Korol, and Andrey V. Solov'yov, “Revealing the mechanism of the low-energy electron yield enhancement from sensitizing nanoparticles”, Phys. Rev. Lett., vol. 114, 063401 (2015)