Fluorescent Dye-Loaded Micellar Clusters: Synthetic Strategies and Optical Characteristics

Fluorescent organic dyes are of great interest for the wide variety of analytical and biochemical applications due to intense and detectible respond of the molecules for characteristics of the media. However, the presence of extended, rigid pi-electronic system leads to high hydrophobicity of fluorescent molecules decreasing its application possibilities for biological systems where hydrophilicity is required. In this concern, we used several synthetic strategies for obtaining of micelles loaded with hydrophobic Coumarin 6 and several dyes of BODIPY family (boron dipyrrins) separately or in mixtures. Micellar clusters obtainment parameters were variated to achieve desirable performance of materials. Used strategies allowed us to sufficiently increase solubility of the dyes in aqueous media as a part of micellar clusters. Moreover the synthetic procedures variation allowed the direct tuning of the dyes spectral characteristics by shifting of monomer-excimer (or aggregate) equilibrium, leading to bathochromic shifts in spectra. For the first time in literature it was shown, that dyes themselves could be used as supporting compounds for micellar clusters formation. Thus, using of the BODIPY as cluster forming agent we drastically reduced the dyes aggregation in the micelles with maintaining intensive fluorescence of the dye, similar results were obtained when nanoparticles of noble metals or d-metal oxides was added to micellar systems. Nanoparticles usage imparted the magnetic properties to the micelles for direct spatial control of clusters distribution. Presented results broadening the possibilities of fluorescent molecules usage as a part of nanoscale micellar system.

The work was supported by the Grant of the President of the Russian Federation No. МК- 8835.2016.3 and RFBR grants No. 16-03-01028, 15-33-20002, 15-43-03214.