Joint forces of HR-spICP-MS and EAF4-MALS for characterization of gold nanorods conjugated with synthetic glycopolymers

As the diversity of nanomaterials is wide and their size can vary by 2 orders of magnitude (1−100 nm), the development of new and advanced analytical tools is of paramount importance for their in-depth characterization, allowing a fundamental understanding of their structure, further alteration and degree of chemical surface functionalization. Herein, we present a new strategy for characterisation of gold nanorods (GNRs) that are of specific interest for biomedical applications due to their unique size-dependent longitudinal surface plasmon resonance band in the visible to near-infrared spectral region. More precisely, we characterized GNRs conjugated with short and long synthetic glycopolymers in terms of particle size, coating thickness, and/or mobility properties used as a diagnostic biosensing platform for lectin detection and compared it to the bare GNRs. This endeavour requires a multidisciplinary approach including a new comprehensive set of fit-for-purpose analytical tools being high resolution single-particle inductively coupled plasma-mass spectrometry (HR-spICP-MS) and electrical asymmetric-flow field-flow-fractionation hyphenated to the multi angle light scattering (EAF4-MALS). GNRs were separated and characterized via EAF4-MALS regarding their size and charge, while HR-spICP-MS provided information on the particle number density, size, size distribution, and the dimensional characterisation. In addition, EAF4-MALS appears to offer suitable approach for estimating coating thickness of glycoconjugated GNRs.

Acknowledgment – MV is a senior postdoctoral researcher of the Research Foundation – Flanders (FWO project number 12ZD120N). AP, PGG, IN and MIG thank the European Union’s Horizon 2020 research and innovation programme under GA 814236 (NanoCarb).