Hybrid Nanoparticles from Random Polyelectrolytes and Carbon Dots.

The present study concerns the preparation of hybrid nanostructures composed of carbon dots (CDs) synthesized in our lab and a double-hydrophilic poly(2-dimethylaminoethyl methacrylate--oligo(ethylene glycol) methyl ether methacrylate) (P(DMAEMA--OEGMA)) random polymer through electrostatic interactions between the negatively charged CDs and the positively charged DMAEMA segments of the polymer. The synthesis of P(DMAEMA--OEGMA) polymer was conducted through RAFT polymerization. Furthermore, the polymer was converted into a strong cationic random polyelectrolyte through quaternization of the amine groups of DMAEMA segments with methyl iodide (CHI), and it was subsequently utilized for the complexation with the carbon dots. The molecular, physicochemical, and photophysical characterization of the aqueous solution of the polymers and their hybrid nanoparticles was conducted using dynamic and electrophoretic light scattering (DLS, ELS) and spectroscopic techniques, such as UV-Vis, fluorescence (FS), and FT-IR spectroscopy. In addition, studies of their aqueous solution using DLS and ELS showed their responsiveness to external stimuli (pH, temperature, ionic strength). Finally, the interaction of selected hybrid nanoparticles with iron (III) ions was confirmed through FS spectroscopy, demonstrating their potential application for heavy metal ions sensing.