Alternative Taylor Dispersion Analysis Methodology for Studying Lectin-Corona on Gold Nanoparticles for Carbohydrate Sensing

Taylor dispersion analysis (TDA) is a technique used for the measurement of the molecular diffusion coefficient (D) of species (organic or inorganic). It is based on band broadening of a sample in a laminar flow. Pulse mode is one of the modes by which TDA can be performed. In this mode, a Gaussian fitting of the signal is required. We propose here an alternate fitting model for the pulse mode, denoted as dual-erf fitting. It allows for the injection of a larger sample volume in the capillary (>1% Vcap), thus extending the use of pulse mode to a low concentration sample. Accurate determination of D of caffeine, reduced glutathione (GSH), insulin from bovine pancreas, bovine serum albumin (BSA), and citrate-capped gold nanoparticles (AuNP) is presented. Theoretical aspects and methodology are described, showing a good correlation between the so-called dual-erf fitting and reported values of the literature. Application of TDA is then performed to study the interaction mechanism between a lectin (concanavalin A and AuNP). Finally, a particular focus is given to the recognition ability of the AuNP-ConA nanoprobe toward carbohydrate moieties (monosaccharides and lipopolysaccharides).