Gold nanodoughnut as an outstanding nanoheater for photothermal applications

TL;DR

This study demonstrates that gold nanodoughnuts outperform other nanoparticle geometries as nanoheaters in photothermal cancer therapy, offering superior, orientation-independent heating efficiency suitable for practical applications.

Contribution

The paper introduces gold nanodoughnuts as highly effective and orientation-insensitive nanoheaters, with a detailed design guide for their experimental fabrication.

Findings

Nanodoughnuts have 35% higher temperature increase than nanodisks.

Heating efficiency of nanodoughnuts is superior and less dependent on orientation.

Nanodoughnuts are ideal for practical photothermal therapy applications.

Abstract

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 doughnut-shaped nanoparticle, demonstrating that the latter exhibits a superior tunable photothermal response in practical illumination conditions, i.e., unpolarized light. Furthermore, we show that nanoparticle heating in fluidic environments, i.e., nanoparticles undergoing Brownian rotations, strongly depends on the particle orientation with respect to the illumination source. We conclude that the heating performance of nanodoughnuts is outstanding, with a temperature increment 35% higher than the second best nanoheater (nanodisks). Furthermore, nanodoughnuts feature a weak dependence on orientation, being therefore, ideal candidates for photothermal therapy applications. Finally, we present a designing guide, covering a wide range of toroid designs, which can help on its experimental implementation.