Current Application of Capillary Electrophoresis in Nanomaterial Characterisation and Its Potential to Characterise the Protein and Small Molecule Corona

Abstract

Due to the increasing use and production of nanomaterials (NMs), the ability to characterise their physical/chemical properties quickly and reliably has never been so important. Proper characterisation allows a thorough understanding of the material and its stability, and is critical to establishing dose-response curves to ascertain risks to human and environmental health. Traditionally, methods such as Transmission Electron Microscopy (TEM), Field Flow Fractionation (FFF) and Dynamic Light Scattering (DLS) have been favoured for size characterisation, due to their wide-availability and well-established protocols. Capillary Electrophoresis (CE) offers a faster and more cost-effective solution for complex dispersions including polydisperse or non-spherical NMs. CE has been used to rapidly separate NMs of varying sizes, shapes, surface modifications and compositions. This review will discuss the literature surrounding the CE separation techniques, detection and NM characteristics used for the analysis of a wide range of NMs. The potential of combining CE with mass spectrometry (CE-MS) will also be explored to further expand the characterisation of NMs, including the layer of biomolecules adsorbed to the surface of NMs in biological or environmental compartments, termed the acquired biomolecule corona. CE offers the opportunity to uncover new/poorly characterised low abundance and polar protein classes due to the high ionisation efficiency of CE-MS. Furthermore, the possibility of using CE-MS to characterise the poorly researched small molecule interactions within the NM corona is discussed.

The Nanomaterial Metabolite Corona Determined Using a Quantitative Metabolomics Approach: A Pilot Study

“…[ 30–32 ] However, the current work implements capillary zone electrophoresis linked to mass spectrometry (CE‐MS), which has recently been proposed as a novel method for NM corona analysis to characterize the highly polar charged metabolites. [ 33 ] CE‐MS has found a niche in metabolomics for the analysis of highly polar and charged metabolites, such as amino acids, organic acids, and nucleotides. [ 34–37 ] Due to the flat flow profile of the electro‐osmotic flow and the fact that only longitudinal diffusion contributes to band broadening in CE, the use of CE‐MS offers an analytical platform with an exceptionally high‐resolution separation and highly selective detection.…”

The rise of the nanomaterial metabolite corona, and emergence of the complete corona

“…As such, a more holistic approach to analyzing the complete NM corona is required, with approaches to characterize and quantify the metabolite corona following in much the same manner as the protein corona is currently analyzed. In the case of the metabolite corona the field of metabolomics has a lot to offer, 87 whereby a global analysis of metabolite (<1500 Da) are analyzed in as unbiased a fashion as possible.…”

Advancement in Analytical and Bioanalytical Techniques as a Boon to Medical Sciences

“…A detector that is becoming more frequently attached to CE is inductively coupled plasma mass spectrometry (ICP-MS). To date, CE-ICP-MS has been performed using a quadrupole detector within the MS allowing a small number of elements to be analyzed at any one time [47].…”