Self-assembled organic fluorescent nano-aggregates in water: bulk properties, nature of self-assembly and detection...

The present study reports the synthesis and evaluation of photoluminescent properties of a novel Aggregation Induced Emission (AIE) and Excited State Intramolecular Proton Transfer (ESIPT) active Schiff's base (E)-N'-(3,5-dibromo-2-hydroxybenzylidene)-4-methylbenzenesulfonohydrazide (MATS) which was found to fluoresce in solution and solid state. The probe molecule was synthesized using various methods including conventional, solvent free and mechanochemical means, which rendered the product in good yields. The AIE properties of the probe was utilized to synthesize Self Assembled Fluorescent Organic Aggregates (SFOAs) in water with average particale size of 185 nm. Various factors affecting the self-assembly of the FOAs were optimized which include pH, concentration, temperature and chaotropic agents. The AIE properties were also utilized for the detection of changes in viscosity highlighting the utilization of the probe as a viscosity sensor (viscochromism). Furthermore, the SFOAs were used for the detection and quantification (LOD = [Formula: see text]M and LOQ = [Formula: see text]M) of picric acid in solution and solid state. The study presents a new Schiff base with solid-state emissive properties, displaying its photoluminescence response to various stimuli and its wide range of applications. It emphasizes the compound's potential for use in advanced fluorescent materials designed for analytical and sensing technologies.