la5b02809_si_001.pdf (8.78 MB)
Download file

Electrophoretic Interpretation of PEGylated NP Structure with and without Peripheral Charge

Download (8.78 MB)
journal contribution
posted on 2015-09-22, 00:00 authored by Reghan J. Hill, Fei Li, Tennyson L. Doane, Clemens Burda
Anchoring poly­(ethylene glycol) (PEG) to inorganic nanoparticles (NPs) permits control over NP properties for a variety of technological applications. However, the core–shell structure tremendously complicates the interpretation of the ubiquitous ζ-potential, as furnished by electrophoretic light-scattering, capillary electrophoresis or gel electrophoresis. To advance the ζ-potentialand the more fundamental electrophoretic mobilityas a quantitative diagnostic for PEGylated NPs, we synthesized and characterized Au NPs bearing terminally anchored 5 kDa PEG ligands with univalent carboxymethyl end groups. Using the electrophoretic mobilities, acquired over a wide range of ionic strengths, we developed a theoretical model for the distributions of polymer segments, charge, electrostatic potential, and osmotic pressure that envelop the core: knowledge that will help to improve the performance of soft NPs in fundamental research and technological applications.