Electrophoretic methods for separation of nanoparticles

Abstract

This article reviews progress in the application of electrophoretic techniques for the separation of nanoparticles. Numerous types of nanoparticles have recently been synthesised and integrated into different products and procedures. Consequently, analytical methods for the efficient characterisation of nanoparticles are now required. Several studies have revealed that gel electrophoresis can readily be used for separating nanoparticles according to their size or shape. However, many other studies focused on separation of nanoparticles by CE. In some cases nanoparticles could be separated by CZE, simply using pure buffer as the BGE. In other studies, buffer additives (most often SDS) were used, enabling fast separations of metallic nanoparticles by size. Other CE methods also allowed for separation of nanoparticle conjugates with biomolecules. Dielectrophoresis is yet another electrophoretic technique useful in separation and characterisation of nanoparticles; particularly nanotubes. Detection methods often used after electrophoretic separation include UV/Vis absorption and fluorescence spectroscopy. Examples of recent and relevant older reports are presented here. The authors conclude that electrophoretic methods for nanoanalysis can provide inexpensive and efficient tools for quality assurance and safety control; and as a consequence, they can augment transfer of nanotechnologies from research to industry.

Detection, characterization and quantification of inorganic engineered nanomaterials: A review of techniques and methodological approaches for the analysis of complex samples

“…Gel electrophoresis and capillary electrophoresis, which are the two electrophoretic techniques most commonly used for separation and characterization of nanoparticles [168][169][170] will be considered. Whereas most of the work with electrophoretic techniques has been devoted to the separation and characterization of nanoparticles according to size, shape and surface functionalization, using electrophoresis as diagnostic tool, the number of applications to real-world samples is still scarce.…”

“…In this sense, bioconjugated quantum dots [175,176] and protein-nanoparticle interactions [177] are commonly studied by CE. Although metal and metal oxide nanoparticles have been separated by using different inorganic buffers as electrolytes, the addition of ionic surfactants appears to be the most convenient mode for separation of metallic nanoparticles [168][169][170]. For instance, Liu et al [178] demonstrated that addition of sodium dodecyl sulphate to the background electrolyte improved the size separation of Au NPs, because of the charge of the NPs is then related to the number of molecules of surfactant adsorbed, which acts as a sort of in situ derivatizing agent.…”

Capillary Electrophoresis in Nanotechnologies versus Nanotechnologies in Capillary Electrophoresis

“…Therefore conventional or microfluidic CE is a good alternative for characterization of colloids and nanomaterials. Review articles focusing on electrophoretic separation of nanoparticles has been published in 2004 by Rodriguez and Armstrong [37], later by Surugau and Urban [38], Pyell [39], Lopez-Lorente et al [40], and in 2017 by Aleksenko et al [41]. Microfluidic format used in nanoparticle separation was reviewed by Salafi et al [42].…”

Measurement and characterization of engineered titanium dioxide nanoparticles in the environment

“…FFF includes flow field-flow fractionation (FFFF), sedimentation field-flow fractionation, and thermal fieldflow fractionation (Gimbert et al, 2005;Baalousha et al, 2006;Hassellöv et al, 2008;Plathe et al, 2010;Baalousha et al, 2011;von der Kammer et al, 2011). Other important methods are centrifugation and ultracentrifugation (Bootz et al, 2004;Hassellöv et al, 2008), size-exclusion chromatography (SEC) (Weinberg et al, 2011), hydrodynamic chromatography (Tiede et al, 2010), capillary electrophoresis (CE) (Celiz et al, 2011), gel electrophoresis (Surugau and Urban, 2009), isoelectric focusing (Howard, 2010), manipulation between solvent phases such as cloud point extraction (Howard, 2010;Liu et al, 2012), and photophoretic velocimetry (Helmbrecht et al, 2011). Most of these fractionation techniques can be coupled with detectors that can trace the separated particles online.…”