Significant breakthrough in fluorescent materials have been witnessed for advancement of science and technology in the last century. In biological study, the development of fluorescent probes with superb brightness, sensitivity, specificity, and biocompatibility is a long-term pursuit of scientific researchers, which allows for real-time monitoring of biological processes and on-site detection of biomolecules. While conventional organic fluorophores often encounter emission quenching in aqueous environment upon aggregation, luminogens with aggregation-induced emission (AIE) characteristics represent a novel class of material that overcomes the limitation of conventional fluorophores. Exploitation of high-performance AIEgens generates unlimited opportunities for a wide range of applicati...[ Read more ]

Significant breakthrough in fluorescent materials have been witnessed for advancement of science and technology in the last century. In biological study, the development of fluorescent probes with superb brightness, sensitivity, specificity, and biocompatibility is a long-term pursuit of scientific researchers, which allows for real-time monitoring of biological processes and on-site detection of biomolecules. While conventional organic fluorophores often encounter emission quenching in aqueous environment upon aggregation, luminogens with aggregation-induced emission (AIE) characteristics represent a novel class of material that overcomes the limitation of conventional fluorophores. Exploitation of high-performance AIEgens generates unlimited opportunities for a wide range of application areas and thus becomes highly demanded.

Many core structures with molecular rotors have been exploited to meet the demand of burgeoning AIE research. Herein, the chromophore thiphenylamine (TPA) has recently emerged as a new class of AIE building block that possesses several notable features, such as easy modification, high brightness, and marked photostability and biocompatibility. Although TPA itself is not AIE active, its propeller-shaped structure and electron-rich nature enable it a perfect constructing unit.

In this thesis, a series of AIE luminogens (AIEgens) built on TPA moiety have been designed and synthesized for diversified utilization. While much of the initial study was focused on simply broadening full-color emission AIEgens, the work has further evolved into development of novel long-wavelength emitting AIEgens and research into their biological behaviors. These TPA-based AIEgens exhibit outstanding performance in photo-induced bioimaging and therapy. Some AIEgens with specific subcellular organelle targetability or elongated wavelength can be readily accessible through structural design.