SwissKnife-Inspired Multifunctional Fluorescence Probes for Cellular Organelle Targeting Based on Simple AIEgens

Facile,
efficient, and mass production of aggregation-induced emission
(AIE) luminogens (AIEgens) with excited-state intramolecular proton
transfer (ESIPT) characteristics was achieved by a one-step condensation
reaction of 2-(hydrazonomethyl)­phenol with benzaldehydes. The function
of as-prepared AIEgens could be tuned easily by varying the functional
group being carried on the phenyl ring of benzaldehyde just like a
Swiss knife handle. The suitable distance and angle of the intramolecular
hydrogen bond in these AIEgens endowed them with ESIPT properties,
intense solid-state luminescence, and large Stokes shifts (155–169
nm). These AIEgens could not only serve as biological probes showing
specific targeting to lipid droplets, endoplasmic reticulum, and lysosomes,
respectively, but also generate reactive oxygen species upon visible
light irradiation to make them promise for photodynamic therapy.