摘要
贵金属纳米结构中的光热效应在肿瘤光热治疗、光热成像、纳米药物等领域具有重要的应用价值.各向异性的芯帽纳米结构以其丰富的可调结构参数和对激发光偏振态敏感的特性,可灵活地在近红外波段获得理想的光学吸收性质,从而可以实现温度的高效调节.本文基于有限元方法研究了颗粒物纳米结构参数对其光热效果的作用规律,数值结果表明:通过对结构参数的微量改变(包括金壳厚度、芯壳比、芯径、金属表面覆盖率等)可实现温度的显著调整;在偏振态的旋转范围(30?—70?)内可快速地产生大温变光热的准线性调整.其不弱于纳米芯壳和纳米棒结构的光热性能可为纳米光热生医研究提供一种新的选择.
Photothermal effects associated with noble metal nanostructures have shown wide potential applications in photothermal cancer therapy, photo-thermal imaging, nanomedicine, etc. These applications benefit from the localized surface plasmon resonance（LSPR） effect of the nanoparticles. Due to the LSPR effect, the nanoparticles exhibit unique optical properties such as strong scattering and absorption in the band ranging from visible to near-infrared region. The absorption enables the plasmonic nanoparticle to be a thermal source to increase the temperature of itself and the localized surrounding environment. Among these particels, the anisotropic core-capped nanostructures distinguish themselves by their strong polarization selectivity. The absorptions are different when the incident light is polarized in the directions vertical（90？） and parallel（0？） to its symmetry axis, respectively. At 90？, a large red-shift can be achieved and the absorption cross section is greatly enhanced. Moreover, their absorption peaks can be flexibly manipulated by slightly adjusting one of the geometrical parameters. However, the photothermal responses to these parameters are left blank. In this paper, photothermal effects of SiO_2@Au core-capped nanoparticles are studied based on the numerical finite elemental analysis method（COMSOL software）. The thermal response to each of the paramenters, including shell thickness, core diameter, core-shell ratio, and metal surface coverage is achieved. The calculation shows that the temperature of these core-capped nanoparticles can be adjusted efficiently in the near infrared band by easily rotating the polarization, i.e.slightly adjusting the geometric parameters. Especially in a range between 30？ and 70？, the temperature varying with the polarization follows almost a linear relationship. The comparisons with other popular structures including solid sphere, core-shell and nanorod are also made. The results indicate that at a similar size, the core-capped structure can off
作者
洪昕
王晨晨
刘江涛
王晓强
尹雪洁
Hong Xin;Wang Chen-Chen;Liu Jiang-Tao;Wang Xiao-Qiang;Yin Xue-Jie(School of Biomedical Engineering,Faculty of Electronic Information and Electrical Engineering,Dalian University of Technology Dalian 116024,China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2018年第19期191-199,共9页
Acta Physica Sinica
基金
国家自然科学基金(批准号:31271064)资助的课题~~
关键词
局域表面等离子体共振
芯帽结构
光热性质
偏振态
localized surface plasmon resonance
core-capped structure
photothermal properties
polarization
