Joint Forces of HR-Spicp-MS and EAF4-MALS for Characterization of Gold Nanorods Conjugated with Synthetic Glycopolymers

Milica Velimirovic,Frank Vanhaecke,Kristof Tirez,Inge Nelissen,Robert Mildner,Matthew I Gibson,Alessia Pancaro,Panagiotis G Georgiou,Christoph Johann

doi:10.3390/iocn2020-07923

Abstract

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 for their in-depth characterization is of paramount importance, allowing a fundamental understanding of their structure, further alteration and degree of chemical surface functionalization. Herein, we present a new strategy for characterization 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 for biosensing of lectins in terms of particle size, coating thickness, and/or mobility properties in comparison with the bare GNRs. This endeavor 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 a multi-angle light scattering detector (EAF4-MALS). GNRs were separated and characterized via EAF4-MALS in terms of their size and charge, while HR-spICP-MS provided information on the particle number density, size, size distribution, and the dimensional characterization. In addition, EAF4-MALS appears to be suitable for estimating coating thickness of glycoconjugated GNRs.

Highlights

Nanomaterials have attracted considerable attention because of their unique physical, chemical, and mechanical properties, exhibiting distinct size-dependent properties in the 1–100 nm range
The spherical equivalent diameter and particle size distribution data for bare gold nanorods (GNRs) and glycoconjugated GNRs (Figure 2, Table 2) was derived in order to provide the thickness of the glycopolymers binded on the GNRs surface
When interpreting mean particle size and particle size distribution data result as provided by HR-spICP-MS, it must be acknowledged that the particle size was not significantly altered after binding synthetic glycopolymers on the GNRs surface, meaning that both short and long glycopolymers did not impact the particle size measurements

Summary

Introduction

Nanomaterials have attracted considerable attention because of their unique physical, chemical, and mechanical properties, exhibiting distinct size-dependent properties in the 1–100 nm range. Proceedings 2020, 4, x FOR PEER REVIEW storage, energy conversion, solar cells, pharmaceuticals, life science applications, optoelectronics, sensing and actuation nanosystems, catalysis, and composite materials [1]. It is expected that in the decade, a countless number of increasingly complex, versatile, and useful nanomaterials will be designed, synthesized, and applied in different research areas. These advanced applications of nanomaterials require their customization in terms of chemical composition/functionalization, size, and morphology. Development of different analytical tools to follow-up the nanomaterial synthesis from an early stage onwards on the one hand and to fully characterize the synthesized NPs on the other is required

Methods

Results

Conclusion