Novel thermal effect at nanoshell heating by pulsed laser irradiation: hoop-shaped hot zone formation

Photonic nanotechnologies have good perspectives to be widely used in biophotonics. In this study we have developed an approach for calculation of nanoparticle temperature field accounting for absorbed local intensity at pulse laser radiation of composite spherical nanoparticles (nanoshells). This approach allowed us to analyze spatial inhomogeneities of light field diffracted into a nanoshell and corresponding distribution of the absorption energy and to provide numerical solution of time-dependent heat conduction equation accounting for corresponding spatially inhomogeneous distribution of heating sources. We were able to predict the appearance of a novel thermal effect - hoop-shaped hot zone on the nanoshell surface. The observed effect has potential applications in cell biology and medicine for controlled cell optoporation and nanosurgery, as well as cancer cell killing.