TY - JOUR
T1 - NMR nanoparticle diffusometry in hydrogels
T2 - enhancing sensitivity and selectivity
AU - de Kort, Daan W.
AU - van Duynhoven, John P.M.
AU - Hoeben, Freek J.M.
AU - Janssen, Henk M.
AU - van As, Henk
PY - 2014/9/1
Y1 - 2014/9/1
N2 - 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 ∼% 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.
AB - 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 ∼% 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.
UR - http://www.scopus.com/inward/record.url?scp=84912079239&partnerID=8YFLogxK
U2 - 10.1021/ac502211q
DO - 10.1021/ac502211q
M3 - Article
C2 - 25141338
AN - SCOPUS:84912079239
SN - 0003-2700
VL - 86
SP - 9229
EP - 9235
JO - Analytical Chemistry
JF - Analytical Chemistry
IS - 18
ER -