THESIS
2018
xxxii, 160, that is, xxxii, 164 pages : illustrations (some color) ; 30 cm
Abstract
Conventional organic fluorescent materials mostly take coplanar conformation, and thus
suffer from fluorescence quenching in the aggregate state or at high concentration due
to the strong intermolecular π-π interaction, which leads to the formation of excimer or
exciplex and decays the exciton energy nonradioatively. Fluorescent materials with
aggregation-induced emission (AIE) characteristics show exactly opposite behaviors.
They are non-emissive when molecules present in solution but fluoresce intensely as aggregates. In general, AIE effect arises from restriction of intramolecular motion (RIM), which includes restriction of intramolecular rotation (RIR) and restriction of
intramolecular vibration (RIV). This discovery brings a new concept in molecular
design that perfectly sol...[
Read more ]
Conventional organic fluorescent materials mostly take coplanar conformation, and thus
suffer from fluorescence quenching in the aggregate state or at high concentration due
to the strong intermolecular π-π interaction, which leads to the formation of excimer or
exciplex and decays the exciton energy nonradioatively. Fluorescent materials with
aggregation-induced emission (AIE) characteristics show exactly opposite behaviors.
They are non-emissive when molecules present in solution but fluoresce intensely as aggregates. In general, AIE effect arises from restriction of intramolecular motion (RIM), which includes restriction of intramolecular rotation (RIR) and restriction of
intramolecular vibration (RIV). This discovery brings a new concept in molecular
design that perfectly solve the detrimental ACQ problems and further encourage
technological innovation in the application field of fluorescence.
Making good use of RIM processes, countless advanced optoelectronic applications
of AIEgens can be developed. Other than utilizations of AIEgens in chemical fields, the
possibility of utilizing AIEgens in biological applications has also been explored.
AIEgens are highly luminescent, photostable and biocompatible, and are thus promising
for various biological applications. Attracted by the superior performance of AIEgens as
novel luminescent materials, in this thesis, I launched a program to develop novel
AIEgen systems and explore their technological applications in biochemical fields.
Specifically, I developed and synthesied a novel boron-based AIEgen and demonstrated
its applications in enantiomer discrimination and morphology visualization of polymer
blends. Besides, two diaminomaleonitrile-based Schiff bases with a donor–acceptor
structure and an aggregation-enhanced emission feature were sythesized and its
mechanochromic properties and applications in bioimaging were reported. Then, I
started focusing on biological applications of the AIEgens. I noticed the importance of
detection and monitoring of cell apoptosis. Thus, a novel AIE-based bioprobe was
synthesis for detection of cell apoptosis as well as differentiation of early and late stages
of cell apoptosis mediated by H
2O
2. Besides, I also utilized a AIEgen for specific
imaging of lipid droplets. Other than exploration of biological applications of AIEgens
in cell systems, I also designed a novel AIEgen with red emission color and exploited it
to image bacteria. I also noticed that this AIEgen can sensitize the generation of ROS
upon photoexcitation, and applied it to wash-free imaging and killing of bacteria.
Post a Comment