title: Behavior of nanoparticles in extended nanospace measured by evanescent wave-based particle velocimetry.
abstract: The transport and behavior of nanoparticles, viruses, and biomacromolecules in 10-1000 nm confined spaces (hereafter "extended nanospaces") are important for novel analytical devices based on nanofluidics. This study investigated the concentration and diffusion of 64 nm nanoparticles in a fused-silica nanochannel of 410 nm depth, using evanescent wave-based particle velocimetry. We found that the injection of nanoparticles into the nanochannel by pressure-driven flow was significantly inhibited and that the nanoparticle diffusion was hindered anisotropically. A 0.2-pN repulsive force induced by the interaction between the nanoparticles and the channel wall is proposed as the dominant factor governing the behavior of nanoparticles in the nanochannel, on the basis of both experimental measurements and theoretical estimations. The results of this study will greatly further our understanding of mass transfer in extended nanospaces.
authors: Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656, Japan.
authors: Yutaka
authors: Y
authors: Kazoe
authors: Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656, Japan.
authors: Kazuma
authors: K
authors: Mawatari
authors: Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656, Japan.
authors: Takehiko
authors: T
authors: Kitamori