Size-Based Characterization of Polysaccharides by Taylor Dispersion Analysis with Photochemical Oxidation or Backscattering Interferometry Detections

Abstract

Taylor dispersion analysis (TDA) is a powerful sizing technique very well suited for (macro)molecules between angstrom and sub-micron (typically up to 200 nm). However, new detection modes are required for non UV-absorbing (macro)molecules such as most of the polysaccharides, including starches. In this work, two different detection modes were compared, backscattering interferometry (BSI) and UV-photooxidation detection (UV-POD). TDA-BSI measures the relative change of the refractive index (RI) between eluent and sample (water as eluent in this work), whereas TDA-UV-POD detects the UV-absorbing photooxidized products of polysaccharides/starches in a strong alkaline media (130 mM NaOH or 1 M KOH). TDA-UV-POD detection was evaluated for linearity and sensitivity at two wavelengths, 214 nm and 266 nm. The mass-average hydrodynamic radius (R h) obtained by TDA-BSI and TDA-UV-POD was found to be in excellent agreement, while higher average R h values were obtained by batch dynamic light scattering (DLS) in the same conditions, due to the higher sensitivity of DLS to large size solutes and aggregates. The hydrodynamic radius distributions obtained by TDA and DLS are intrinsically different but both techniques were found to be complementary, providing useful information on sample dispersity. Owing to the absence of the stationary phase, low sample consumption with straightforward sample preparation (no filtration), and no calibration, TDA is anticipated to become a method of choice for the size-based characterization of polysaccharides, including starches.

Critical assessment of relevant methods in the field of biosensors with direct optical detection based on fibers and waveguides using plasmonic, resonance, and interference effects

“…Instead of normal UV-Vis detection, the measurement of refractive index is a potential alternative detector [281]. Also, characterization of polysaccharides by Taylor dispersion analysis is reported to achieve a powerful sizing technique for macromolecules between nanometers and microns [282]. A modification of the porous silicon technique is a chip with a stamped pattern which contains a gold particles surface in stripes; BSA is binding to the gold particle, and the micro-patterns of such beads function as a type of refraction grating [283].…”

3D Printed Instrument for Taylor Dispersion Analysis with Two-Point Laser-Induced Fluorescence Detection

“…TDA has evolved from studying gaseous diffusion coefficients in large tubes to capillary-based solution phase measurements of small molecules, , macromolecular complexes, − and even micron-scale particles . In TDA, analysis time is proportional to the square of the tubing radius.…”

Antigen-Adjuvant Interactions in Vaccines by Taylor Dispersion Analysis: Size Characterization and Binding Parameters

“…Taylor dispersion analysis (TDA) has recently paid more and more attention and appears as a competitive and alternative technique for the determination of diffusion coefficients and hydrodynamic radii of proteins, macromolecules, nanoparticles, and their assemblies [11][12][13][14][15][16][17] . TDA is an absolute method based on the analysis of the dispersion of a solute plug in a capillary under a laminar Poiseuille flow, due to the combined action of convection and molecular diffusion.…”

“…Taylor dispersion analysis (TDA) has recently attracted more and more attention and appears as a competitive and alternative technique for the determination of diffusion coefficients and hydrodynamic radii of proteins, macromolecules, nanoparticles, and their assemblies. − TDA is an absolute method based on the analysis of the dispersion of a solute plug in a capillary under a laminar Poiseuille flow due to the combined action of convection and molecular diffusion. From the elution profile, it is possible to determine the molecular diffusion coefficient ( D ) and therefore the hydrodynamic radius ( R h ) of solutes ranging from angstroms to submicrons. , In the case of mixtures composed of two populations of different sizes, which are both stable at the time scale of the analysis, TDA signal is the sum of two Gaussian peaks.…”