Hu Yi, Cheng Xuanhong, Daniel Ou-Yang H
Department of Physics, Lehigh University, Bethlehem, PA 18015 USA ; Current address: Institute of Human Virology, University of Maryland, School of Medicine, Baltimore, MD 21201 USA.
Biomed Opt Express. 2013 Aug 14;4(9):1646-53. doi: 10.1364/BOE.4.001646. eCollection 2013.
Fluorescence correlation spectroscopy (FCS) is one of the most sensitive methods for enumerating low concentration nanoparticles in a suspension. However, biological nanoparticles such as viruses often exist at a concentration much lower than the FCS detection limit. While optically generated trapping potentials are shown to effectively enhance the concentration of nanoparticles, feasibility of FCS for enumerating field-enriched nanoparticles requires understanding of the nanoparticle behavior in the external field. This paper reports an experimental study that combines optical trapping and FCS to examine existing theoretical predictions of particle concentration. Colloidal suspensions of polystyrene (PS) nanospheres and HIV-1 virus-like particles are used as model systems. Optical trapping energies and statistical analysis are used to discuss the applicability of FCS for enumerating nanoparticles in a potential well produced by a force field.
荧光相关光谱法（FCS）是用于计数悬浮液中低浓度纳米颗粒的最灵敏方法之一。然而，诸如病毒之类的生物纳米颗粒的存在浓度往往远低于FCS的检测限。虽然光学产生的捕获势被证明能有效提高纳米颗粒的浓度，但FCS用于计数场富集纳米颗粒的可行性需要了解纳米颗粒在外部场中的行为。本文报道了一项结合光学捕获和FCS的实验研究，以检验现有的颗粒浓度理论预测。聚苯乙烯（PS）纳米球和HIV-1病毒样颗粒的胶体悬浮液用作模型系统。利用光学捕获能量和统计分析来讨论FCS在由力场产生的势阱中计数纳米颗粒的适用性。
