Fluorescent materials have been widely used in the bioimaging and biosensing field owing to the ease of operation, high sensitivity and excellent selectivity. For traditional organic fluorophores, it is well-recognized that their fluorescence will be quenched in concentrated solutions, where the formation of intermolecular π-π interactions is detrimental for the emission efficiency. In the practical applications, researchers generally adopt chemical and physical maneuvers to avoid the aggregation-caused quenching (ACQ) effect. This fixed stereotype is longstanding in our minds and no one dares to think outside the box. Despite few researchers found some emitters fluorescing more efficiently in the solid state than solution state, they fail to explore the phenomenon profoundly an...[ Read more ]

Fluorescent materials have been widely used in the bioimaging and biosensing field owing to the ease of operation, high sensitivity and excellent selectivity. For traditional organic fluorophores, it is well-recognized that their fluorescence will be quenched in concentrated solutions, where the formation of intermolecular π-π interactions is detrimental for the emission efficiency. In the practical applications, researchers generally adopt chemical and physical maneuvers to avoid the aggregation-caused quenching (ACQ) effect. This fixed stereotype is longstanding in our minds and no one dares to think outside the box. Despite few researchers found some emitters fluorescing more efficiently in the solid state than solution state, they fail to explore the phenomenon profoundly and carry on the systematic study.

In 2001, our group proposed a new concept termed as “aggregation-induced emission” (AIE) from an accidental discovery. The abnormal phenomenon gave us the sense that there should be a universally applicable working principle hidden behind it. Therefore, tremendous endeavors were put to decipher its mechanism. The throughout investigation resulted in the massive output of AIE-active systems. Meanwhile, AIE luminogens (AIEgens) have been employed in a variety of real application, such as organic light-emitting diodes, chemical sensing, biomolecular sensing, bioimaging in vitro/vivo and theranostics.

This thesis mainly corelates with the exploration of AIE probes for selective cancer cell imaging. A series of AIEgens have been designed and synthesized for the detection of biogenic analytes. A water-soluble teraphenylethylene derivative based on “AIE” strategy is exploited in the visualization of hypoxic degree in living cells. Another hypoxia-sensing probe is established to realize hypoxia detection and sense the dynamic change of lipid droplets at the same time. To fulfill the imaging of estrogen receptor dynamic in cancer cells, a photoactivatable tamoxifen-mimicking AIE probe with selective imaging of estrogen receptor-positive cancer cells was first time proposed. Finally, we develop a novel strategy to prepare core-shell nanoparticles, namely AIE-TF dots, for mitochondria-targeted imaging in vitro.