Abstract
From the diffusional behavior of nanoparticles
in heterogeneous hydrogels, quantitative information about
submicron structural features of the polymer matrix can be
derived. Pulsed-gradient spin-echo NMR is often the method
of choice because it measures diffusion of the whole ensemble
of nanoparticles. However, in 1H diffusion-ordered spectroscopy
(DOSY), low-intensity nanoparticle signals have to be
separated from a highly protonated background. To circumvent
this, we prepared 19F labeled, PEGylated, water-soluble
dendritic nanoparticles with a 19F loading of ~7 wt % to
enable background free 19F DOSY experiments. 19F nanoparticle
diffusometry was benchmarked against 1H diffusion-T2
correlation spectroscopy (DRCOSY), which has a stronger
signal separation potential than the commonly used 1H DOSY experiment. We used bootstrap data resampling to estimate
confidence intervals and stabilize 2D-Laplace inversion of DRCOSY data with high noise levels and artifacts, allowing
quantitative diffusometry even at low magnetic field strengths (30 MHz). The employed methods offer significant advantages in
terms of sensitivity and selectivity.
Original language | English |
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Pages (from-to) | 9229-9235 |
Journal | Analytical Chemistry |
Volume | 86 |
DOIs | |
Publication status | Published - 2014 |
Keywords
- fluorescence recovery
- laplace inversion
- polymer-solutions
- field gradient
- diffusion
- resolution
- mobility
- gels
- spectroscopy
- kinetics