Synthesis and Characterization of Chitosan‐Based Polyelectrolyte Complexes Doped with Xanthene Dyes

Abstract

Biocompatible chitosan-based polyelectrolyte complexes (PECs) doped with xanthene dyes (fluorescein, eosin Y, erythrosin B, rhodamine 6G) were synthesized and characterized by scanning electron microscopy, dynamic light scattering, zeta potential measurements, and absorption and luminescence (including polarized, time-resolved, and phosphorescence) spectroscopy. The results are discussed in terms of the mechanism and rigidity of dye-PEC binding, the heavy-atom effect in dyes and PEC stability. Eosin Y is found to be the optimal dopant, providing both a high dye content in PECs and a high quantum yield of fluorescence.

A Comparative Study on the Photophysics and Photochemistry of Xanthene Dyes in the Presence of Polyamidoamine (PAMAM) Dendrimers

“…Although our present data show a similar trend in selectivity (e.g., K bind‐RB/G5 ≈6 K bind‐Eos/G5 ), the K bind values were obtained under experimental conditions that excluded the possibility of aggregation of the dyes. Other authors have studied the binding interactions in various supramolecular systems comprised by xanthene dyes and a host (H=enzymes, micelles, or polyelectrolytes), and reported the same sequence of selectivity as that reported herein (i.e., Eos/H<Ery/H<RB/H). They ascribed such results to the hydrophilic–lipophilic balance of the dyes, which depended on the amount and size of halogen atoms in their structure.…”

Photoluminescence properties of self-assembled chitosan-based composites containing semiconductor nanocrystals

“…The mechanism of the formation of NCs-free particles from chitosan and chondroitin sulfate was discussed previously. 10,11 Electrostatic linking of positively charged amino groups of chitosan with negatively charged carboxyl and sulfur groups of chondroitin (the same for hyaluronic acid and heparin 15 ) plays a crucial role in the particles formation. The efficiency of the electrostatic linking is proportional to the number of charged groups determined by dissociation constants of polyelectrolytes under given conditions.…”

“…The method used for the synthesis of biopolymer particles from chitosan and chondroitin sulfate was similar to that described previously. 10,11 Chitosan solution of 0.1% w/v concentration was pre-cleaned from insoluble impurities by filtration through a filter paper. The chondroitin sulfate solution of 0.1% w/v concentration was added dropwise to the chitosan solution under intensive magnetic stirring.…”

Aminofluoresceins Versus Fluorescein: Ascertained New Unusual Features of Tautomerism and Dissociation of Hydroxyxanthene Dyes in Solution

“…In the above studies, the dyes may be imbedded not only in water but also in a variety of microenvironments. For instance, the photophysical and spectral properties were studied for hydroxyxanthenes fixed in surfactant micelles and chitosan-based polyelectrolytes; , the singlet oxygen delivery by Rose Bengal B was studied in mesostructured silica nanoparticles . Besides studies of fluorescein behavior in room-temperature ionic liquids (RTILs), the ions of fluorescein dyes are already used in the preparation of a new kind of RTIL as an anionic component. , In turn, the medium effects may seriously influence the spectral and protolytic properties of the dyes.…”