Rational design of aggregation‐induced emission‐active bisboron complexes (BOQHYs) for high‐fidelity lipid droplet imaging

Abstract Lipid droplets (LDs) are dynamic intracellular organelles that participate in a wide range of physiological and pathological processes. Consequently, the development of high‐selectivity and high‐resolution tools for LD detection and tracking is of paramount importance. In this study, we describe the straightforward synthesis of a series of novel BODIPY analogs, BOQHYs 3a – 3e , through the condensation of 2,3‐dihydrazinylquinoline with acetone or benzophenone, followed by complexation with BF 3 ·OEt 2 . Spectroscopic properties indicate that these dyes exhibited significantly larger Stokes shifts (>100 nm) than the commercial LD‐Tracker BODIPY 493/503 (≈10 nm). Additionally, the incorporation of phenyl “rotors” endows BOQHYs 3b – 3e with heightened aggregation‐induced emission activity, viscosity responsiveness, and exceptional lipophilicity, enabling their selective staining of LDs in a rapid and wash‐free manner, with outstanding signal‐to‐noise ratios. Time‐resolved confocal fluorescence imaging of 3d further validates these dyes’ capability to effectively capture LD fusion and fission events, highlighting their potential applications in LD‐related cell biology and disease diagnostics.