Measurement of Brownian motion of nanoparticles in suspension using a network-based PTV technique
- Banerjee A. (Mechanical, Aerospace and Biomedical Engineering Department University of Tennessee) ;
- Choi C. K. (Mechanical, Aerospace and Biomedical Engineering Department University of Tennessee) ;
- Kihm K. D. (Mechanical, Aerospace and Biomedical Engineering Department University of Tennessee) ;
- Takagi T. (Department of Electrical Engineering Kushiro National College of Technology)
- Published : 2004.12.01
Abstract
A comprehensive three-dimensional nano-particle tracking technique in micro- and nano-scale spatial resolution using the Total Internal Reflection Fluorescence Microscope (TIRFM) is discussed. Evanescent waves from the total internal reflection of a 488nm argon-ion laser are used to measure the hindered Brownian diffusion within few hundred nanometers of a glass-water interface. 200-nm fluorescence-coated polystyrene spheres are used as tracers to achieve three-dimensional tracking within the near-wall penetration depth. A novel ratiometric imaging technique coupled with a neural network model is used to tag and track the tracer particles. This technique allows for the determination of the relative depth wise locations of the particles. This analysis, to our knowledge is the first such three-dimensional ratiometric nano-particle tracking velocimetry technique to be applied for measuring Brownian diffusion close to the wall.