HLCT-AIE active deep blue fluorophores and their versatile applications: a multifunctional approach for advanced white LED materials, picric acid sensing and fingerprint visualization

Abstract

Here, we present the design and synthesis of a new hybridized local and charge-transfer (HLCT) fluorophore (BI-Ac) based on benzilimidazole–anthracene with aggregation-induced emission (AIE) properties. The synergistic interplay between HLCT and AIE phenomena is harnessed in this context for dual-purpose applications in solid-state illumination and explosive detection, thereby facilitating the advancement of multifunctional luminescent materials. Excellent photoluminescence in both solution and solid state is made possible by the customized molecular architecture, which successfully combines the stiffness of anthracene with the bipolar properties of the benzilimidazole scaffold. The compound was effectively integrated into a blue and white light-emitting diode (LED), which demonstrated remarkable electroluminescent characteristics with a color rendering index (CRI) of 80 with ideal white light emission. Furthermore, the fluorophore exhibited pronounced selectivity and sensitivity for detecting picric acid (PA) through the fluorescence quenching mechanism, attaining a detection limit of 3.23 μM and quenching constant K_sv of 6.03 × 10³ M⁻¹. Moreover, its robust luminescence and superior contrast imaging capabilities facilitate the high-resolution visualization of latent fingerprints (LFP) (level 3 detection) on diverse substrates when exposed to ultraviolet light.