Characterization of Core-Shell nanoparticles using Field-Flow Fractionation and Single-Particle ICP-MS

Soheyl Tadjiki, Manuel Montano, James Ranville and Ron Beckett
Postnova Analytics, US

Keywords: core-shell, nanoparticle, field flow fractionation, single particle ICP-MS


A methodology has been developed to measure mass, size and density of the core and the shell of a core-shell nanoparticle for the first time. The FFF-based methodology allows for the measurement of the mass of the nanoparticle using Centrifugal Field-Flow Fractionation (CFFF) and the volume by Asymmetrical Flow Field-Flow Fractionation (AsFlFFF). The nanoparticle density can then be calculated from the obtained mass and volume data. Mass of the core can be measured either by Single-Particle ICP-MS or by the FFF analysis of the uncoated core nanoparticle. The methodology was validated by measuring the density of different sized polystyrene latex beads standards. The measured densities of the polystyrene standards were in the range of 1.04 g/mL to 1.05 g/mL Data will be presented for the analysis of a silver-shelled gold nanoparticle standard. The densities of the core, shell and core-shell nanoparticle were measured as 12.8 g/mL, 8.9 g/mL, and 9.5 g/mL respectively. The data suggests a 33% porosity in the gold core and a 16% porosity in the silver shell.