Taylor Dispersion of Inorganic Nanoparticles and Comparison to Dynamic Light Scattering and Transmission Electron Microscopy

Abstract

A B S T R A C TTaylor dispersion analysis (TDA) is an analytical method that has so far mainly been utilized to determine the diffusion coefficient of small molecules, and proteins. Due to increasing interest in nanoscience, some research has been done on the applicability of TDA towards characterizing nanoparticles. This work aims to expand this knowledge and give insight into the range for which TDA can be used for nanoparticle characterization, focusing on various materials and sizes. The TDA setup shown in this work was successful in characterizing all engineered metallic, non-metallic nanoparticles, and proteins tested in this work. Results were compared to dynamic light scattering and electron microscopy, and were in good agreement with both methods. Taking into consideration the wide range of nanoparticle sizes that can be characterized, the minimal sample preparation, and sample volume, required and the simplicity of the method, TDA can be considered as a valuable technique for nanoparticle characterization.When looking at the huge array of properties that nanoparticles (NPs) possess, it is not surprising that they have found their way into a multitude of scientific research areas, and industrial applications [1]. Interesting NP phenomena are mostly governed by their size, and for many applications it is imperative that the NPs not only have a very specific size but also display a narrow particle size distribution [2]. For example, the heating properties of superparamagnetic iron oxide nanoparticles (SPIONs), which are being investigated as mediators of hyperthermia in cancer treatment, are dependent on their size and size distribution. Therefore, the characterization of nanoparticle size is crucial to ensure their functionality [3]. For this purpose, several analytical methods such as dynamic light scattering (DLS), NP tracking analysis (NTA), UV-Vis spectroscopy, field-flow fractionation, analytical ultracentrifugation, and transmission electron microscopy (TEM) have been utilized to characterize NP sizes and size distributions [4][5][6][7][8]. Each method has its advantages and disadvantages, and a combination of techniques is typically recommended to adequately characterize NPs [4]. For example, TEM provides information about NP core sizes, but cannot evaluate NP hydrodynamic diameters. Conversely, DLS and NTA can evaluate particle hydrodynamic diameter and colloidal stability, but are limited by the quality of light scattering and require a deeper knowledge of the theory and model-fitting to properly analyze the raw data. With scattering-based techniques, the limit of detection for NPs depends on the sensitivity of the detection of scattered light, and factors such as the material refractive index, particle size, shape and the wavelength used for detection. Furthermore, standard DLS measurements struggle with analyzing NPs in complex environments (e.g. proteincrowded suspensions, high particle concentration etc.) or samples where only limited sample preparation is possible [9][10][11]. There are pos...

Preparation of metallosupramolecular single-chain polymeric nanoparticles and their characterization by Taylor dispersion

“…To circumvent these issues, Taylor dispersion analysis (TDA) was carried out as a reliable method capable of accurately determining particle sizes across several orders of magnitude, 57 while offering outstanding precision. [33][34][35][36]58 This technique relies on the UV-light absorption of the particles ( Fig. 2a and 3d-f ), which scales linearly with their hydrodynamic radius, and thus allows for a reliable determination of particle sizes, even in the presence of minor amounts of larger aggregates.…”

“…2a and 3d-f ), which scales linearly with their hydrodynamic radius, and thus allows for a reliable determination of particle sizes, even in the presence of minor amounts of larger aggregates. 35,36 In TDA measurements, the translational selfdiffusion and sheer-enhanced dispersion of SCPNs that are subjected to a steady laminar flow through a microfluidic channel is monitored by measuring the absorption profile (λ = 280 ± 10 nm) at fixed positions. 57 The width of the concentration band of the absorbing particles changes at the different positions in the channel due to the combined effects of convection and diffusion, which, after fitting to the Stokes-Einstein equation, yields the hydrodynamic radii (see the ESI † for a detailed description).…”

“…The method provides for an improved 'signal-to-noise' ratio in favour of single particles, even in the presence of a relatively small number of larger aggregates. [33][34][35][36] The battery of analytic techniques allowed us to demonstrate that the addition of the acrylic, Mebip-containing polymers to solutions containing Fe 2+ , Zn 2+ , or Eu 3+ ions at low concentrations reliably furnishes SCPNs with intramolecular metal-ligand complexes, irrespective of the molecular weight of the polymer and the nature of the metal ion.…”

Functionalized gold nanoparticles for sample preparation: A review

“…Thereby, comprehensive characterization with multiple techniques is of great importance for the quality control of the synthesized nanoparticles. In order to avoid misleading interpretations, a combination of multiple techniques is typically recommended for adequate and reliable characterization .…”

“…Taylor dispersion analysis (TDA) is considered as a valuable technique for the analysis of the hydrodynamic radius and the diffusion coefficient of biopharmaceuticals (e.g., therapeutic antibodies , peptides and proteins). The application of TDA for the characterization of gold nanoparticles has been performed to determine the diffusion coefficient and the hydrodynamic diameter of nanoparticles with minimal sample preparation . The nanoparticle sample is injected as a plug into a cylindrical tube, i.e., a fused silica capillary.…”