Ultrafast Pulsed Laser Induced Nanocrystal Transformation in Colloidal Plasmonic Vesicles
Ultrafast Pulsed Laser Induced Nanocrystal Transformation in Colloidal Plasmonic Vesicles
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DOI：
10.1002/adom.201800726
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发表时间：
2018-09
影响因子：
9
通讯作者：
M. Karim;Xiuying Li;P. Kang;J. Randrianalisoa;Dineli T. S. Ranathunga;S. Nielsen;Zhenpeng Qin;D. Qian
中科院分区：
文献类型：
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作者：
M. Karim;Xiuying Li;P. Kang;J. Randrianalisoa;Dineli T. S. Ranathunga;S. Nielsen;Zhenpeng Qin;D. Qian
等离子体囊泡由聚合物涂层内或磷脂核心周围的多个金纳米晶体组成。作为一种多功能纳米结构，它具有独特的优势，可以组装小纳米颗粒（<5 nm）用于快速肾脏清除，强等离子体耦合用于超灵敏的生物传感和成像，以及近红外光吸收用于药物释放。因此，了解等离子体囊泡与光的相互作用对于广泛的应用至关重要。本文采用实验和计算相结合的方法研究了超快皮秒脉冲激光诱导胶体等离子体囊泡中的相变。实验观察到合并和转化成较大的纳米粒子时，激光脉冲处理的小纳米晶体首次报道。负责的实验观察的基本机制进行了研究，具有耦合电磁/分子动力学模拟的多物理场计算方法。这项研究首次揭示了纳米颗粒加热和激光增强布朗运动的结合是观察到的混合的原因。相应地，激光能量密度，颗粒间的距离，和水的存在被确定为最重要的因素，控制相变。从这项研究中建立的指导方针可以用来设计一系列涉及激光与等离子体纳米粒子相互作用的生物医学和纳米制造应用。
Plasmonic vesicle consists of multiple gold nanocrystals within a polymer coating or around a phospholipid core. As a multifunctional nanostructure, it has unique advantages of assembling small nanoparticles (<5 nm) for rapid renal clearance, strong plasmonic coupling for ultrasensitive biosensing and imaging, and near‐infrared light absorption for drug release. Thus, understanding the interaction of plasmonic vesicles with light is critically important for a wide range of applications. In this paper, a combined experimental and computational study is presented on the nanocrystal transformation in colloidal plasmonic vesicles induced by the ultrafast picosecond pulsed laser. Experimentally observed merging and transformation of small nanocrystals into larger nanoparticles when treated by laser pulses is first reported. The underlying mechanisms responsible for the experimental observations are investigated with a multiphysics computational approach featuring coupled electromagnetic/molecular dynamics simulation. This study reveals for the first time that combined nanoparticle heating and laser‐enhanced Brownian motion is responsible for the observed nanocrystal merging. Correspondingly, laser fluence, interparticle distance, and presence of water are identified as the most important factors governing the nanocrystal transformation. The guidelines established from this study can be employed to design a host of biomedical and nanomanufacturing applications involving laser interaction with plasmonic nanoparticles.