Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
Small. 2010 Oct 18;6(20):2272-80. doi: 10.1002/smll.201001109.
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.
基于等离子体的光热疗法是贵金属纳米结构最引人关注的应用之一。光热转换效率是实际实现这一应用的一个重要参数。通过用热电偶直接测量金纳米晶溶液的温度，并基于能量平衡进行分析，系统地研究了等离子体共振波长、粒子体积、壳层涂层和组装对金纳米晶光热转换效率的影响。当金纳米晶的等离子体共振波长等于照射激光波长时，金纳米晶溶液的温度达到最大值约 75°C。对于具有相似形状的金纳米晶，纳米晶越大，光热转换效率越低。通过改变金纳米晶的等离子体共振能量，壳层涂层和组装也可以控制光热转换。此外，用带隙能量小于照射激光能量的半导体材料涂覆金纳米晶可以提高光热转换效率，因为存在额外的光吸收通道。
