Research Institute of Advanced Materials (RIAM), Department of Materials Science and Engineering , Seoul National University , Seoul 08826 , Korea.
Department of Chemistry , Seoul National University , Seoul 08826 , Republic of Korea.
ACS Appl Mater Interfaces. 2018 Dec 5;10(48):41655-41663. doi: 10.1021/acsami.8b14787. Epub 2018 Nov 19.
Plasmon-enhanced particle trapping was demonstrated using a hybrid structure of nanoparticles and nanorods. In order to intensify localized surface plasmon resonance (LSPR), gold nanoparticles (AuNPs) were deposited on zinc oxide nanorods (ZnONRs). The synergistic effect caused by the hybrid structure was identified experimentally. Numerical analysis revealed that the LSPR-induced photophysical processes such as plasmonic heating and near-field enhancement were improved by the existence of ZnONRs. The role of the ZnONR in enhancing the particle-trapping velocity was explored by examining the scattered electric field, Poynting vector, and temperature gradient over the nanostructures calculated from the simulation. It was found that polystyrene microparticles and Escherichia coli cells were successfully trapped by using the ZnONR/AuNP plasmonic structure. A relatively high dielectric constant and nanorod geometry of ZnO enabled the hybrid substrate to enhance trapping performance, compared with a control case fabricated using only gold nanoislands.
利用纳米粒子和纳米棒的混合结构实现了等离子体增强的粒子捕获。为了增强局域表面等离子体共振（LSPR），在氧化锌纳米棒（ZnONRs）上沉积了金纳米粒子（AuNPs）。实验证实了混合结构的协同效应。数值分析表明，LSPR 诱导的光物理过程，如等离子体加热和近场增强，由于 ZnONRs 的存在而得到改善。通过检查从模拟计算得出的纳米结构上的散射电场、坡印廷矢量和温度梯度，研究了 ZnONR 在提高粒子捕获速度方面的作用。结果发现，成功地使用 ZnONR/AuNP 等离子体结构捕获了聚苯乙烯微球和大肠杆菌细胞。与仅使用金纳米岛制造的对照样品相比，ZnO 的相对较高的介电常数和纳米棒几何形状使混合衬底能够增强捕获性能。
