Photophysical investigation of phenanthrene derived 1,2,3-triazole molecule in non-ionic and cationic micellar environments

Nanoscale materials including micelle-based systems have been employed as drug carriers. Carriers can enable the transport of hydrophobic molecules in the bloodstream, regulate drug release, and minimize side effects. In the present study two categories of surfactants, non-ionic (Tween 20 and Triton X-100) and cationic (CTAB and DTAB), were used to solubilize a hydrophobic chemosensor for biologically relevant ions in aqueous environments. The chemosensor was a phenanthrene-based 1,2,3-triazole phenol derivative (PhTP). The interaction of PhTP in the microheterogenous media resulted in changes in its photophysical properties with enhanced fluorescence, almost 3 folds for Tween 20 and Triton X-100, and 15 folds for CTAB. Successful encapsulation of PhTP within the micelles for all categories of surfactants was substantiated with increased quantum yield and higher order binding constants (10⁵–10⁶ M⁻¹). The encapsulation region was determined in separate studies with the addition of NaCl and fluorescence quencher Cu²⁺. Those studies revealed that with Tween 20, PhTP was fully within the core of the micelle, and for the cationic surfactants and Triton X-100, the sensor resided in the micelles’ stern layer. PhTP entrapment was further substantiated by dynamic light scattering experiments with Tween 20 and CTAB. In the presence of PhTP, there was a considerable increase in the hydrodynamic size of the micelles, and for the zeta potential, there was a decrease with Tween 20 and an increase with CTAB. Overall, this work demonstrates a pathway for generating physiologically compatible formulations for hydrophobic 1,2,3-triazoles derivatives such as PhTP using non-ionic and cationic surfactants.