ESIPT-AIE Active Schiff Base Fluorescent Organic Nanoparticles Based on 2-(2-(4-(4-bromo Phenyl) Thiazol-2-yl)Vinyl)Phenol (BTVP) Utilized as a Multi-Functional Fluorescent Probe

The present study reports the synthesis and characterization of Aggregation-Induced Emission (AIE) - Excited-state intramolecular proton transfer (ESIPT) active 2-(2-(4-(4-bromo phenyl) thiazol-2-yl)vinyl)phenol (BTVP). The AIE properties of BTVP in Acetone/Water solution are investigated, and fluorescent organic nanoparticles (FONs) (sizes ranging from 150-200 nm) are prepared in various water fractions (fH2O). The established visco-chromic property suggests that the restriction of intramolecular rotation is responsible for the AIE-ESIPT behavior of the molecule, providing a means to sense viscosity. The synthesized FONs act as fluorescence chemosensors to detect Al3+ ions via a photoinduced electron transfer (PET) mechanism. Job's, Benesi-Hildebrand method, and 1HNMR titration confirm the 1:1 binding of BTVP with the metal ion. Studies on the emission concerning pH reveal the high stability of FONs over a broad range of pH, and a gradual change in the emission wavelength for the BTVP-Al3+ complex (BTVP-Al) is observed, providing a means to sense pH ranging from 2-8. The solid-state photoluminescence of BTVP is used for latent fingerprint detection, demonstrating its efficiency in detecting both primary and secondary information. Additionally, both BTVP FNOs and BTVP-Al are used in cell imaging, where specific nuclear staining with BTVP-Al and cytoplasm staining with BTVP are observed. 2-(2-(4-(4-bromo phenyl) thiazol-2-yl)vinyl)phenol (BTVP)-based fluorescent organic nanoparticles display numerous applications such as viscochromism, Al3+ sensing, pH sensing, latent fingerprint detection, and cell imaging. The probe shows an Excited State Intramolecular Proton Transfer-Aggregation Induced Emission fluorescent property. The aluminium complex of the probe demonstrates a PET mechanism, with a hypsochromic shift in the emission.image