Molecular Engineering of Excited-State Dynamics via ICT toward a Cross-Reactive Single-Fluorophore Array for Discriminative Sensing of VOCs

Abstract

The development of high-performance fluorescent film-based sensors (FFSs) for on-site, real-time detection requires fluorescent units that overcome the limitations of conventional materials, such as aggregation-caused quenching (ACQ) and poor photostability. Herein, we report a novel donor–acceptor fluorophore (BDP1) engineered with high microenvironmental polarity sensitivity via an intramolecular charge-transfer (ICT) mechanism. The derived nanostructured co-assembled film (BDP1/C1) integrates three critical attributes for practical volatile organic compound (VOC) sensing: (i) exceptional photochemical stability, preventing photobleaching during repeated use; (ii) pronounced polarity sensitivity, enabling fast and reversible analyte detection; and (iii) a single-fluorophore-based sensing platform that simplifies device design and discriminates seven distinct VOCs through pattern recognition. This work establishes BDP1/C1 as a robust and responsive optical sensing material, demonstrating a strategic advance toward miniaturized, high-performance FFSs.