Organic dye assemblies with aggregation‐induced photophysical changes and their bio‐applications

Abstract

Phototheranostics provide a safe, effective, and noninvasive way for the diagnosis and treatment of contemporary diseases, and organic dyes play a vital role. For example, chemical modification endowed dyes with powerful reactive oxygen species or heat generation ability, favoring for photodynamic therapy and photoacoustic (PA) imaging guided photothermal therapy (PTT) of serious diseases. Therefore, photophysical properties manipulation of dyes has become the focus in current dye chemistry research. The development of aggregate science has made great effort to solve this problem. In recent years, a large number of studies have focused on molecular aggregation behavior and its effect on photophysical performance. The most famous example is the discovery of aggregation‐induced emission (AIE) phenomenon. Based on AIE theory, more theories for revealing the relationship between molecular aggregation behavior and photophysical properties were proposed and elucidated. The photophysical property changes caused by dye aggregation have become a unique discipline, guiding the development of molecular science and material science. With the help of molecular self‐assembly, controllable aggregation of dyes can be realized, and stable nano‐theranostic reagents can be obtained. Furthermore, constructing dye assemblies with various photophysical properties will greatly reduce the cost of theranostic reagents, thus, expanding biomedical applications of organic dyes. Therefore, this review focuses on the photophysical characteristic changes caused by dye aggregation and their biological applications including, fluorescence/phosphorescence/PA imaging as well as photodynamic and PTT. This review will provide guidance for the design of organic dyes, the development of controllable aggregation methods, and the construction of multifunctional phototheranostic reagents.

Aggregation Turns BODIPY Fluorophores into Photosensitizers: Reversibly Switching Intersystem Crossing On and Off for Smart Photodynamic Therapy

“…On the other side, it could be exploited to turn fluorophores into heavy-atomfree photosensitizers (PSs) for photodynamic therapy (PDT). [21][22][23][24] Page 2 of 29 CCS Chemistry efficiency. [47][48][49] The ROS generation of traditional photosensitizers is usually degraded in aggregation states because of efficient decay of triplet states.…”

Tunable Linear and Nonlinear Optical Properties from Room Temperature Phosphorescent Cyclic Triimidazole‐Pyrene Bio‐Probe

“…Moreover, the development of aggregate materials with emission tunability and coexistence of multiple radiative behaviors is a burgeoning area where highly potential applications could be explored. [33,34] Here we report on the preparation and characterization of different solvated (namely TTPyr(Et) and TTPyr(Me)) and not solvated (TTPyr(RT) and TTPyr(HT)) solid phases of 3-(pyren-1-yl) triimidazo[1,2-a:1',2'-c:1'',2''-e][1,3,5]triazine hereafter TTPyr. The thermally induced structural transformation (from TTPyr(Et) to TTPyr(HT) through TTPyr(RT)) among the phases involves bright and tunable prompt and long-lived emissions as well as NLO (nonlinear optical) properties switched on by the packing features of the chromophore.…”

Synthesis and Characterization of Zinc (II) Phthalocyanine for Screening Potential Solar Cell Dye Application

“…[12] NMR sample aggregation is far lower than that seen in Figure 1 UV-Vis samples, due to the sample concentrations. [5,6]…”

“…Both aggregation in Dye Sensitized Solar Cells as well as Luminescent Solar Concentrators typically provides undesirable effects such as aggregation-caused quenching (ACQ), lowering solar cell device performance such as Short Circuit Current and Open Circuit Voltage [1,2]. This effect is very common for organic semiconducting dyes, theorised but not yet proven to result from p-p stacking interactions causing aggregation and thus aggregation-caused quenching [5,6]. Phthalocyanine is an organic semiconducting dye that's notoriously insoluble, theorised to result from its conjugated π framework allowing p-p orbital stacking interactions to from between two Phthalocyanine molecules.…”