Dissemin is shutting down on January 1st, 2025

Published in

American Chemical Society, Analytical Chemistry, 18(86), p. 9229-9235, 2014

DOI: 10.1021/ac502211q

Links

Tools

Export citation

Search in Google Scholar

NMR Nanoparticle Diffusometry in Hydrogels: Enhancing Sensitivity and Selectivity

This paper is made freely available by the publisher.
This paper is made freely available by the publisher.

Full text: Download

Green circle
Preprint: archiving allowed
  • Must obtain written permission from Editor
  • Must not violate ACS ethical Guidelines
Orange circle
Postprint: archiving restricted
  • Must obtain written permission from Editor
  • Must not violate ACS ethical Guidelines
Red circle
Published version: archiving forbidden
Data provided by SHERPA/RoMEO

Abstract

From the diffusional behavior of nanoparticles in heterogeneous hydrogels, quantitative information about sub-micron 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.