title: Understanding the photothermal conversion efficiency of gold nanocrystals.
abstract: Plasmon-based photothermal therapy is one of the most intriguing applications of noble metal nanostructures. The photothermal conversion efficiency is an essential parameter in practically realizing this application. The effects of the plasmon resonance wavelength, particle volume, shell coating, and assembly on the photothermal conversion efficiencies of Au nanocrystals are systematically studied by directly measuring the temperature of Au nanocrystal solutions with a thermocouple and analyzed on the basis of energy balance. The temperature of Au nanocrystal solutions reaches the maximum at ∼75 °C when the plasmon resonance wavelength of Au nanocrystals is equal to the illumination laser wavelength. For Au nanocrystals with similar shapes, the larger the nanocrystal, the smaller the photothermal conversion efficiency becomes. The photothermal conversion can also be controlled by shell coating and assembly through the change in the plasmon resonance energy of Au nanocrystals. Moreover, coating Au nanocrystals with semiconductor materials that have band gap energies smaller than the illumination laser energy can improve the photothermal conversion efficiency owing to the presence of an additional light absorption channel.
authors.affiliation: Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
authors.forename: Huanjun
authors.initials: H
authors.lastname: Chen
authors.forename: Lei
authors.initials: L
authors.lastname: Shao
authors.forename: Tian
authors.initials: T
authors.lastname: Ming
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Sun
authors.forename: Chunmei
authors.initials: C
authors.lastname: Zhao
authors.forename: Baocheng
authors.initials: B
authors.lastname: Yang
authors.forename: Jianfang
authors.initials: J
authors.lastname: Wang
mesh_terms: D000042:Absorption; D006046:Gold / Q000737:chemistry*; D006358:Hot Temperature; D008027:Light; D053768:Metal Nanoparticles / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology; D020349:Surface Plasmon Resonance
chemical_list: D006046:Gold