Effect of Salt on Polyelectrolyte-Probe Dynamics Using Fluorescence Recovery After Photo-bleaching

Abstract

The dynamics of dextran probe inside poly(allylamine) hydrochloride (PAH) solutions with varying salt concentration to the polyelectrolyte solutions were analyzed through fluorescence technique. Fluorescence Recovery After Photobleaching is one among the innovative and interesting approaches in the field of pharmaceutical research which provides the benefit of measuring diffusion in micrometer scale in a highly specific way in complex biomaterials, in vivo. The observed probe diffusion showed increase in the magnitudes with increased salt concentration but up to an optimum range. The microviscosity experienced by the probe was decreased in lower polymer concentration confirming the presence of higher number of voids or free space at concentrated samples. The polymer aggregation at lower concentration readily vanishes with addition of external electrolyte to the solution. In general, the probe-polyelectrolyte dynamics is quite dependent on polymer-polymer and polymer-probe interactions than in bulk viscosity of the solutions.