Optical Absorption Manipulation of Spherical Microcapsules Mediated by Buffer Nanoparticles

We simulate and examine the absorption dynamics of the near-infrared optical radiation in a spherical microcapsule surrounded by solid nanoparticles of different optical properties (metal, biocompatible dielectric) with the use of numerical finite-difference time-domain (FDTD) calculations. A model microcapsule resembles a microcontainer used in modern bio- and medical technologies for targeted delivery of therapeutic nanodoses of drugs to the desired region of biological tissues. We show that the optical field superlocalization in the “hot regions” on the microcapsule surface takes place due to light scattering on nanoparticles. The three-fold light absorption enhancement can be achieved due to the addition of buffer nanoparticles.