Hydration-driven diffusion and organization in cationic micelles inhibits the self-assembly of an organic...

The family of bis-indolyl methanes (BIMs) includes compounds that are significant in biological, optoelectronic, and molecular sensor research arenas and are often found to aggregate in the solution phase. Molecules exhibiting aggregation-caused fluorescence quenching (ACFQ) pose major limitations for sensor and drug development applications. A strong fluorescence from the ACFQ-sensitive probes can be developed through proper encapsulation within organized supramolecular assemblies. This course of action makes the BIMs physicochemically stable and free from spectroscopic limitations. The principal aim of the current study is focused on the comprehensive photophysical, organization and dynamic properties of supra-molecular encapsulation-induced controlled disaggregation of a self-assembled bis-indole derivative, 3,3'-bisindolyl(phenyl)methane (BIPM), in well-characterized cationic micellar membranes differing in their hydrophobic chain length. Steady-state and time-resolved spectroscopic techniques, light scattering and microscopic studies, and in silico molecular docking simulations have been carried out for this purpose. Notable disparities in the degree and rate of emission recovery of BIPM in biomimetic model systems due to the varied effects of nanocavity confinement have been observed and discussed. Hydration-driven solvent exposure is the key driving force controlling the reorganization of the aggregated bis-indole molecules. Hence, this investigation into the reversible control of molecular aggregation and subsequent emission modulation for BIPM or any other similar probe associations in aqueous media will provide deep insights into supramolecular encapsulation-driven optical probe development.