Gold nanodoughnut as an outstanding nanoheater for photothermal applications

Photoinduced hyperthermia is a cancer therapy technique that induces death to cancerous cells via heat generated by plasmonic nanoparticles. While previous studies have shown that some nanoparticles can be effective at killing cancer cells under certain conditions, there is still a necessity (or the need) to improve its heating efficiency. In this work, we perform a detailed thermoplasmonic study comparing the most effective nanoparticle geometries up to now with a dougnhut-shaped nanoparticle, demonstrating that the latter exhibits an outstanding tuneable photothermal response in realistic illumination conditions, i.e., partially polarized light. Furthermore, we show that nanoparticle heating in microfluidic environments, i.e. nanoparticles suffering arbitrary rotations, strongly depends on the particle orientation with respect to the illumination source, a circumstance often neglected in photothermal applications. We conclude that heating of nanodoughnuts depends weakly on orientation and light depolarization, being therefore ideal candidates for photothermal therapy applications. Finally, we present a nanodoughnut designing guide, covering a wide range of toroid designs, which can help on its experimental implementation.