Probing microenvironment of micelle and albumin using diethyl 6-(dimethylamino)naphthalene-2,3-dicarboxylate: An electroneutral solvatochromic fluorescent probe.

Synthesis, single-crystal X-ray characterization, and spectroscopic investigation of small, non-charged diethyl 6-(dimethylamino)naphthalene-2,3-dicarboxylate (DMNDC) by UV-Visible, steady-state, and time-resolved fluorescence reveal a series of interesting photophysical properties originating from the intrinsic intramolecular charge transfer (ICT) state, leading to diverse applications. Stokes shift, lifetime, and emission maxima of DMNDC show a very good correlation with ET(30) solvent polarity scale for a series of different polarity solvents, confirms that it has very good environment sensitivity. Furthermore, this dye has been found to be an exceptionally suitable probe for determining Critical Micelle Concentration (CMC) and probing self-organization processes of five different type of surfactant with structural diversity. A 20-60nm blue shift in emission maxima accompanied by a large fluorescence lifetime enhancement (ca. 23ns) was observed upon relocation of DMNDC into a hydrophobic microenvironment. Along with this, the small size, electroneutrality, pH stability, and excellent solvatochromic fluorescent properties are employed for deciphering the number of hydrophobic binding pockets with strong affinity and their local microenvironment present in Bovine Serum Albumin (BSA).