Study on the statistical intensity distribution (SID) of fluorescent nanoparticles in TIRFM measurement

Zheng, Xu; Shi, Fei; Silber-Li, Zhanhua

doi:10.1007/s10404-018-2145-2

Cited by 9 publications

(14 citation statements)

References 33 publications

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“…4(c) is shown the corresponding temporal evolution of the reduced dispersion coefficient for z 0 = 600±15 nm. While the data does not reach exactly (especially at early times) the theoretical prediction for the dot condition due to the polydispersity of the particles (and thus non-unique altitudes for a given intensity [43]), it is systematically below the one for the half-line condition and approaches the τ 2 asymptotic behaviour predicted by Eq. 3 for n = 0.…”

contrasting

confidence: 56%

“…Figure 1(c) shows the streamwise velocity profiles for 55 nm-radius particles in water and several pressure drops. The solid lines show that the profiles are well approximated by linear functions (see SI and [35,43] for a discussion of the small non-linearities). The spread of v xintercept values arises from the spread of values for I 0 at each pressure, z = 0 being taken as the mean of Π log I 0 over the different ∆P ; z = 0 is thus resolved to within 20 nm of the solid/liquid interface assuming no slip [35] as justified in the SI.…”

mentioning

confidence: 98%

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Time dependence of advection-diffusion coupling for nanoparticle ensembles

Vilquin,

Bertin,

Soulard

et al. 2020

Preprint

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Particle transport in fluids at micro-and nano-scales is important in many domains. As compared to the quiescent case, the time evolution of particle dispersion is enhanced by coupling: i) advection along the flow; and ii) diffusion along the associated velocity gradients. While there is a well-known, long-time limit for this advection-diffusion enhancement, understanding the short-time limit and corresponding crossover between these two asymptotic limits is less mature. We use evanescent-wave video microscopy for its spatio-temporal resolution. Specifically, we observe a near-surface zone of where the velocity gradients, and thus dispersion, are the largest within a simple microfluidic channel. Supported by a theoretical model and simulations based on overdamped Langevin dynamics, our experiments reveal the crossover of this so-called Taylor dispersion from short to long time scales. Studying a range of particle size, viscosity and applied pressure, we show that the initial spatial distribution of particles can strongly modify observed master curves for short-time dispersion and its crossover into the long-time regime.

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confidence: 56%

mentioning

confidence: 98%

Time dependence of advection-diffusion coupling for nanoparticle ensembles

Vilquin,

Bertin,

Soulard

et al. 2020

Preprint

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show abstract

“…To investigate the effects of defocussing and polydispersity, we have used 63 the signal intensity distribution analyses of ref. 62, simultaneously fitting the distribution of intensities and velocity profiles and find good agreement with the slopes measured here, within 10% or so and not varying systematically with the imposed pressure.…”

Section: Limitations Of the Particle Altitude Determinationsupporting

confidence: 78%

“…6 2)), which are validated by the agreement of our measured water viscosity using TIRFM with accepted values. More directly, and while not shown here, we have verified that the angles thus measured in situ are in agreement with the typical method of projecting the laser through a half sphere placed atop the objective, 48,62 with the horizontal position of the laser measured as a function of x M .…”

Section: Angle Measurementsupporting

confidence: 78%

“…These are mainly due to optical aberrations: because of the finite depth of field of the objective (415 nm), off-focal-plane tracers appear relatively less bright than their infocus counterparts. Expanding the typical 62 Lorentzian multiplicative factor for the intensity as a function of the particle's distance from the focal plane, and considering that the focal plane is typically a few hundred nanometres from the surface, we do not expect that the near-wall linear profile exhibits more than 10% change in the shear rate due to this defocusing effect. Polydispersity is also expected to play a role in tracer altitude estimation.…”

Section: Limitations Of the Particle Altitude Determinationmentioning

confidence: 99%

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