:Aggregation-induced emission
{{Short description|Luminescent phenomenon in certain fluorescent dyes}}
Aggregation-induced emission (AIE) is a phenomenon in which certain organic luminophores (fluorescent dyes) exhibit stronger emission of light in their aggregated or solid state compared to when they are in solution.{{cite journal |last1=Hong |first1=Yuning |last2=Lam |first2=Jacky W. Y. |last3=Tang |first3=Ben Zhong |date=2011 |title=Aggregation-induced emission |url=https://zenodo.org/record/851710 |journal=Chemical Society Reviews |volume=40 |issue=11 |pages=5361–88 |doi=10.1039/c1cs15113d |pmid=21799992}}{{cite journal |last1=Mei |first1=Ju |last2=Hong |first2=Yuning |last3=Lam |first3=Jacky W. Y. |last4=Qin |first4=Anjun |last5=Tang |first5=Youhong |last6=Tang |first6=Ben Zhong |date=August 2014 |title=Aggregation-Induced Emission: The Whole Is More Brilliant than the Parts |journal=Advanced Materials |volume=26 |issue=31 |pages=5429–5479 |bibcode=2014AdM....26.5429M |doi=10.1002/adma.201401356 |pmid=24975272 |s2cid=29645895}}{{cite journal |last1=Mei |first1=Ju |last2=Leung |first2=Nelson L. C. |last3=Kwok |first3=Ryan T. K. |last4=Lam |first4=Jacky W. Y. |last5=Tang |first5=Ben Zhong |date=22 October 2015 |title=Aggregation-Induced Emission: Together We Shine, United We Soar! |journal=Chemical Reviews |volume=115 |issue=21 |pages=11718–11940 |doi=10.1021/acs.chemrev.5b00263 |pmid=26492387}} This counterintuitive behavior contrasts with most organic compounds, which typically show reduced photoemission in the solid state due to processes like aggregation-caused quenching. AIE is primarily attributed to restricted molecular motion in the aggregated state (decreased flexibility), which suppresses nonradiative energy dissipation and enhances fluorescence efficiency.{{Cite journal |last1=Suzuki |first1=Satoshi |last2=Sasaki |first2=Shunsuke |last3=Sairi |first3=Amir Sharidan |last4=Iwai |first4=Riki |last5=Tang |first5=Ben Zhong |last6=Konishi |first6=Gen-ichi |date=2020 |title=Principles of Aggregation-Induced Emission: Design of Deactivation Pathways for Advanced AIEgens and Applications |journal=Angewandte Chemie International Edition |language=en |volume=59 |issue=25 |pages=9856–9867 |doi=10.1002/anie.202000940 |issn=1521-3773 |pmc=7318703 |pmid=32154630}} The increase of fluorescence emission intensity was also observed upon restriction of molecular motion due to host-guest interactions and viscosity increase,{{Cite journal |last=Strada |first=Rebecca |last2=Dunlop |first2=David |last3=Vorba |first3=Michal |last4=Raj |first4=Amar |last5=Tütüncü |first5=Büşra Buse |last6=Myllyperkiö |first6=Pasi |last7=Slanina |first7=Tomáš |last8=Kumpulainen |first8=Tatu |last9=Sebej |first9=Peter |date=2025 |title=Restricting Intramolecular Motion Converts Non-Fluorescent Semicroconaine Dyes into Turn-On Aggregation-Induced Emission Probes |url=http://pubs.rsc.org/en/Content/ArticleLanding/2025/QM/D5QM00030K |journal=Materials Chemistry Frontiers |language=en |doi=10.1039/D5QM00030K |issn=2052-1537|doi-access=free }} which is not a common behavior of such host-guest complexes.{{Cite journal |last=Gilberg |first=Laura |last2=Zhang |first2=Ben |last3=Zavalij |first3=Peter Y. |last4=Sindelar |first4=Vladimir |last5=Isaacs |first5=Lyle |date=2015 |title=Acyclic cucurbit[n]uril-type molecular containers: influence of glycoluril oligomer length on their function as solubilizing agents |url=https://xlink.rsc.org/?DOI=C5OB00184F |journal=Organic & Biomolecular Chemistry |language=en |volume=13 |issue=13 |pages=4041–4050 |doi=10.1039/C5OB00184F |issn=1477-0520 |pmc=4366302 |pmid=25731639}}
Aggregation-induced emission enhancement
The phenomenon in which organic luminophores show higher photoluminescence efficiency in the aggregated state than in solution is called aggregation-induced emission enhancement (AIEE). Some luminophores, e.g., diketopyrrolopyrrole-based and sulfonamide-based luminophores, only display enhanced emission upon entering the crystalline state. That is, these luminophores are said to exhibit crystallization-induced emission enhancement (CIEE).{{cite journal |last1=Jin |first1=Yi |last2=Xu |first2=Yanbin |last3=Liu |first3=Yinling |last4=Wang |first4=Lingyun |last5=Jiang |first5=Huanfeng |last6=Li |first6=Xianjie |last7=Cao |first7=Derong |title=Synthesis of novel diketopyrrolopyrrole-based luminophores showing crystallization-induced emission enhancement properties |journal=Dyes and Pigments |date=September 2011 |volume=90 |issue=3 |pages=311–318 |doi=10.1016/j.dyepig.2011.01.005 }}{{cite journal |last1=Virk |first1=Tarunpreet Singh |last2=Ilawe |first2=Niranjan V. |last3=Zhang |first3=Guoxian |last4=Yu |first4=Craig P. |last5=Wong |first5=Bryan M. |last6=Chan |first6=Julian M. W. |title=Sultam-Based Hetero[5]helicene: Synthesis, Structure, and Crystallization-Induced Emission Enhancement |journal=ACS Omega |date=20 December 2016 |volume=1 |issue=6 |pages=1336–1342 |doi=10.1021/acsomega.6b00335 |pmid=31457199 |pmc=6640820 }} Luminophores such as noble metallic nanoclusters show higher photoluminescence efficiency in the aggregated state than homogenous dispersion in solution. This phenomenon is known as Aggregation-Induced Emission (AIE).{{cite journal |last1=Moghadam |first1=Fatemeh Mortazavi |last2=Rahaie |first2=Mahdi |title=A signal-on nanobiosensor for VEGF165 detection based on supraparticle copper nanoclusters formed on bivalent aptamer |journal=Biosensors and Bioelectronics |date=May 2019 |volume=132 |pages=186–195 |doi=10.1016/j.bios.2019.02.046 |pmid=30875630 |s2cid=80613434 }}{{cite journal |last1=Mortazavi Moghadam |first1=Fatemeh |last2=Bigdeli |first2=Mohammadreza |last3=Tamayol |first3=Ali |last4=Shin |first4=Su Ryon |title=TISS nanobiosensor for salivary cortisol measurement by aptamer Ag nanocluster SAIE supraparticle structure |journal=Sensors and Actuators B: Chemical |date=October 2021 |volume=344 |pages=130160 |doi=10.1016/j.snb.2021.130160 }}
Aggregation-induced emission polymer
Fluorescence-emission Polymer is a kind of polymer which can absorb light of certain frequency and then give out light.{{cite journal |last1=Han |first1=Ting |last2=Deng |first2=Haiqin |last3=Qiu |first3=Zijie |last4=Zhao |first4=Zheng |last5=Zhang |first5=Haoke |last6=Zou |first6=Hang |last7=Leung |first7=Nelson L. C. |last8=Shan |first8=Guogang |last9=Elsegood |first9=Mark R. J. |last10=Lam |first10=Jacky W. Y. |last11=Tang |first11=Ben Zhong |title=Facile Multicomponent Polymerizations toward Unconventional Luminescent Polymers with Readily Openable Small Heterocycles |journal=Journal of the American Chemical Society |date=9 April 2018 |volume=140 |issue=16 |pages=5588–5598 |doi=10.1021/jacs.8b01991 |pmid=29630372 |s2cid=207190130 |url=https://dspace.lboro.ac.uk/2134/32941 }} These polymers can be applied in biomaterial area. Due to their high biocapacity and fluorescence, they can help researchers to find and mark the location of proteins. And polymers with property of aggregation-induced emission can also help to protect the healthy tissues from the harm of the medicines.{{cite journal |last1=Sun |first1=Wenjing |last2=Luo |first2=Li |last3=Feng |first3=Yushuo |last4=Cai |first4=Yuting |last5=Zhuang |first5=Yixi |last6=Xie |first6=Rong-Jun |last7=Chen |first7=Xiaoyuan |last8=Chen |first8=Hongmin |title=Aggregation-Induced Emission Gold Clustoluminogens for Enhanced Low-Dose X-ray-Induced Photodynamic Therapy |journal=Angewandte Chemie International Edition |date=5 September 2019 |volume=59 |issue=25 |pages=9914–9921 |doi=10.1002/anie.201908712 |pmid=31418982 |s2cid=201020605 }}
References
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