[Zurück]

V. Weiss, K. Wieland, K. Balantic, A. Schwaighofer, B. Lendl, G. Ramer, G. Friedbacher, E. Pittenauer, A. Centrone, M. Marchetti-Deschmann, G. Allmaier:
"Novel offline hyphenation strategies for characterization of nanoparticles size-selected after gas-phase electrophoresis (nES GEMMA instrumentation)";
Poster: ANAKON 2019, Münster, Germany; 25.03.2019 - 28.03.2019.

Gas-phase electrophoresis on a nES GEMMA (nano electrospray gas-phase electrophoretic mobility molecular analysis) instrument enables the characterization of nanoparticles in the range of several few up to several hundred nm surface-dry particle diameter (electrophoretic mobility diameter, EMD). Single-charged analytes obtained after a nES process with subsequent drying of droplets and charge equilibration are separated in a high laminar sheath flow of air and a tunable electric field [1]. Detection is particle-number based according to the recommendations of the European Commission for nanoparticle characterization (2011/696/EU from October 18th, 2011).

Exchanging the nES GEMMA detector unit by an electrostatic nanoparticle aerosol sampler (ENAS) unit allows collection of nanoparticles at a certain EMD for subsequent analysis employing orthogonal methods, for instance microscopy or immunologic techniques [2]. We now present the application of optical spectroscopy for the characterization of size-separated nanoparticles. For our proof-of-concept studies we size-collected material either on supports enabling subsequent IR spectroscopic or Raman characterization of analytes [3, 4]. Alternatively, gold coated silicon wafers enabling MALDI mass spectrometry of size-selected nanoparticles were applied (unpublished data).

In both cases we opted for unilamellar liposomes, vesicles comprised of a lipid bilayer and an aqueous interior. Encapsulation of different cargo in vesicles of varying lipid composition enabled to demonstrate the applicability of spectroscopic/-metric methods for the characterization of vesicles after nES GEMMA based analysis and size-separation.

References:

[1] S. L. Kaufman et al., Anal Chem 1996, 68, 1895-1904., [2] M.Havlik et al., Anal Chem 2015, 87, 8657-8664., [3] K. Wieland et al., Nano Res 2018, DOI: 10.1007/s12274-018-2202-x, [4] V. U. Weiss et al., submitted Anal Chem 2018.

The authors acknowledge funding from the Austrian Science Fund (FWF, P25749-B20), the Austrian Research Funding Association (FFG, 843594) and the University of Maryland (Award 70NANB14H209 to GR).

GEMMA, gas-phase electrophoresis, nanoparticle, mass spectrometry, liposome, AFM, spectroscopy