On the photothermal response of DNA-Au core/shell nanotoroids as potential agents for photothermal therapies

Abstract

Plasmonic nanoparticles play a pivotal role in various research areas due to their exceptional optical and thermo-optical properties, like high spectral tunability and efficient light-to-heat conversion. Gold, with its biocompatibility, low cytotoxicity, and tunable resonances, makes gold nanoparticles ideal for photothermal therapies. Geometries, including spheres, core-shells, rods, disks, stars, nanocages, and nanotoroids, are extensively studied, with the gold nanodoughnut emerging as one of the most promising ones due to its ability to produce high temperatures and rotational stability. Nevertheless, the fabrication of metallic toroidal shapes remains a challenge. Recent advances in DNA-based nanotechnology, especially DNA-origami techniques, provide feasible route for the fabrication of this geometry through metallization reactions or attachment of metal nanoparticles. However, particles manufactured using this method possess a DNA core that influences their thermoplasmonic performance. In this work, a theoretical investigation is conducted on the thermoplasmonic response of DNA-origami-based core/shell toroids (CSTs) for photothermal applications. Key parameters that optimize the CST thermoplasmonic response are identified, and compared with their solid counterparts and discrete metallic coatings. Additionally, the CSTs tolerance to random rotations is assessed, providing insights into their behavior in fluidic environments and implications for its practical consideration.