|本期目录/Table of Contents|

 液体环境对光镊稳定捕获的影响(PDF)

《纳米技术与精密工程》[ISSN:1672-6030/CN:12-1351/O3]

期数:
2017年6期
页码:
431-437
栏目:
出版日期:
2017-11-15

文章信息/Info

Title:
 Influence of Liquid Environment on Stable Optical Trapping
作者:
胡春光1 王思蓉1 高晓晴1 苏晨光1 李宏斌12 胡晓东1 胡小唐1
 1. 精密测试技术及仪器国家重点实验室(天津大学), 天津 300072; 2. 加拿大英属哥伦比亚大学化学系,温哥华V6T 1Z4
Author(s):
 Hu Chunguang1 Wang Sirong1 Gao Xiaoqing1 Su Chenguang1 Li Hongbin12 Hu Xiaodong1 Hu Xiaotang1
 1. State Key Laboratory of Precision Measuring Technology and Instruments(Tianjin University), Tianjin 300072, China;

2. Department of Chemistry, University of British Columbia, Vancouver V6T 1Z4, Canada

关键词:
 光镊 热梯度力 非水环境 微球捕获
Keywords:
 optical tweezer thermophoretic force nonwater solution trapping of microsphere
分类号:
TN247;TB92;TH741
DOI:
DOI 1013494/j.npe.20160098
文献标识码:
A
摘要:
 具有高精度和高灵敏度的光镊技术在生物领域,特别是生物单分子力谱测量中,有着广泛和重要的应用.对微米量级粒子的稳定捕获是光镊技术开展应用研究的基础.非水环境在生物单分子研究领域越来越受到重视,本文对不同液体环境影响光阱稳定捕获的热力学因素进行研究,结合热力学仿真建立了热梯度力模型,分析了微球在向会聚光束焦点横向运动过程中受到的热梯度力的变化,并与T矩阵理论仿真得到的光阱力空间分布进行比较,总结了液体环境影响热梯度力的关键参数.在异丙醇环境里捕获直径为5 μm硅球的实验中,5 μm硅球无法进入光阱.针对这一实验现象,结合实验中微球的运动状态,通过分析仿真的光阱力和热梯度力在空间上的分布差异,给出了合理的解释,证明了上述理论的可行性,为评估不同溶液环境里激光热效应对光阱捕获微球的影响提供了分析方法.
Abstract:
 Optical tweezers is a versatile tool in the research of single biomolecule force spectroscopy. Stable trapping and flexible manipulation of the particles are the fundamentals of optical tweezers. Determining factors such as the numerical aperture of objective lens, the shape of laser beam, and the material and size of the trapped particle have been studied over the past 30 years. However, the influence of liquid environment has always been ignored. Since nonwater solutions are increasingly used in biomolecular studies, this paper lays emphasis on the influence of liquid environment, which is mainly reflected in the nonignorable thermophoretic force under some specific circumstances. Based on thermodynamics, the spatial distribution of thermophoretic force in the focal plane of laser is simulated. This distribution is compared with the simulated optical force profile using the Tmatrix method. For further research, this paper investigates the optical trapping of 5 μmindiameter silica beads in two solutions, water and isopropanol, respectively. At first, beads which are suspended in the solutions were lifted above the beam focus. Then they fell down under gravity so as to see whether they can be trapped. It is found that 5 μmindiameter silica beads cannot enter the beam center in isopropanol whereas they can be trapped in water. This result emphasizes the nonignorable influence of thermophoretic force in nonwater solutions. Meanwhile, the equilibrium between the two forces introduces a novel way to evaluate the magnitude of thermophoretic force in the process of optical trapping.

参考文献/References

备注/Memo

备注/Memo:

收稿日期: 2017-08-10.
基金项目: 国家自然科学基金资助项目(61223008); 天津市自然科学基金资助项目(15JCZDJC31600).
作者简介: 胡春光(1981—),男,博士,副教授.
通讯作者: 胡春光, cghu@tju.edu.cn

更新日期/Last Update: 2017-12-15