PMID- 32013190 OWN - NLM STAT- MEDLINE DCOM- 20201120 LR - 20240328 IS - 1420-3049 (Electronic) IS - 1420-3049 (Linking) VI - 25 IP - 3 DP - 2020 Jan 29 TI - ICT and AIE Characteristics Two Cyano-Functionalized Probes and Their Photophysical Properties, DFT Calculations, Cytotoxicity, and Cell Imaging Applications. LID - 10.3390/molecules25030585 [doi] LID - 585 AB - Two probes, AIE-1 and AIE-2, were synthesized to investigate the effect of substitutional functional group on aggregation (aggregation-caused quenching (ACQ) or aggregation-induced emission (AIE)) and intramolecular charge transfer (ICT) behavior as well as on the cell imaging aspect. The yellow-color non-substituted probe AIE-1 showed weak charge-transfer absorption and an emission band at 377 nm and 432 nm, whereas the yellowish-orange color substituted probe AIE-2 showed a strong charge-transfer absorption and an emission band at 424 nm and 477 nm in THF solvent. The UV-Vis studies of AIE-1 and AIE-2 in THF and THF with different water fractions showed huge absorption changes in AIE-2 with high water fractions due to its strong aggregation behavior, but no such noticeable absorption changes were observed for AIE-1. Interestingly, the fluorescence intensity of AIE-1 at 432 nm gradually decreased with increasing water fractions and became almost non-emissive at 90% water. However, the monomer-type emission of AIE-2 at 477 nm was shifted to 584 nm with a 6-fold increase in fluorescence intensity in THF-H(2)O (1:9, v/v) solvent mixtures due to the restriction of intramolecular rotation on aggregation in high water fractions. This result indicates that the probe AIE-1 shows ACQ and probe AIE-2 shows AIE behaviors in THF-H(2)O solvent mixtures. Furthermore, the emission spectra of AIE-1 and AIE-2 were carried out in different solvent and with different concentrations to see the solvent- or concentration-dependent aggregation behavior. Scanning electron microscope (SEM) and dynamic light scattering (DLS) experiments were also conducted to assess the morphology and particle size of two probes before and after aggregation. Both of the probes, AIE-1 and AIE-2, showed less toxicity on HeLa cells and were suitable for cell imaging studies. Density functional theory (DFT) calculation was also carried out to confirm the ICT process from an electron-rich indole moiety to an electron-deficient cyano-phenyl ring of AIE-1 or AIE-2. FAU - Tarai, Arup AU - Tarai A AD - Center for Biomedical Photonics, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China. FAU - Huang, Meina AU - Huang M AD - Center for Biomedical Photonics, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China. FAU - Das, Pintu AU - Das P AD - Center for Biomedical Photonics, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China. FAU - Pan, Wenhui AU - Pan W AD - Center for Biomedical Photonics, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China. FAU - Zhang, Jianguo AU - Zhang J AD - Center for Biomedical Photonics, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China. FAU - Gu, Zhenyu AU - Gu Z AD - Center for Biomedical Photonics, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China. FAU - Yan, Wei AU - Yan W AD - Center for Biomedical Photonics, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China. FAU - Qu, Junle AU - Qu J AUID- ORCID: 0000-0001-7833-4711 AD - Center for Biomedical Photonics, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China. FAU - Yang, Zhigang AU - Yang Z AD - Center for Biomedical Photonics, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China. LA - eng GR - 61875131/61525503/61620106016/61835009/81727804/National Natural Science Foundation of China/ GR - 2015KGJHZ002/2016KCXTD007/Key Project of Department of Education of Guangdong Province/ GR - 2014A030312008/Guangdong Natural Science Foundation Innovation Team/ GR - JCYJ20170818100931714/ JCYJ20170412105003520/Shenzhen Basic Research Project/ GR - GJHZ20180928161811821/Shenzhen International Cooperation Project/ PT - Journal Article DEP - 20200129 PL - Switzerland TA - Molecules JT - Molecules (Basel, Switzerland) JID - 100964009 RN - 0 (Acetonitriles) RN - 0 (Aldehydes) RN - 0 (Cytotoxins) RN - 0 (Fluorescent Dyes) RN - 0 (Solvents) RN - 23G40PRP93 (benzyl cyanide) SB - IM MH - Acetonitriles/chemistry MH - Aldehydes/chemistry MH - Cell Survival/drug effects MH - Cytotoxins/chemistry MH - Diagnostic Imaging MH - Electrons MH - *Fluorescence MH - Fluorescent Dyes/chemical synthesis/*chemistry/toxicity MH - HeLa Cells MH - Humans MH - Microscopy, Electrochemical, Scanning MH - Photochemical Processes MH - Scattering, Radiation MH - Solvents MH - Spectrometry, Fluorescence PMC - PMC7037400 OTO - NOTNLM OT - aggregation OT - cell imaging OT - charge-transfer OT - cytotoxicity OT - emission OT - solvatochromism COIS- The authors declare no conflict of interest. EDAT- 2020/02/06 06:00 MHDA- 2020/11/21 06:00 PMCR- 2020/01/29 CRDT- 2020/02/05 06:00 PHST- 2019/12/11 00:00 [received] PHST- 2020/01/20 00:00 [revised] PHST- 2020/01/24 00:00 [accepted] PHST- 2020/02/05 06:00 [entrez] PHST- 2020/02/06 06:00 [pubmed] PHST- 2020/11/21 06:00 [medline] PHST- 2020/01/29 00:00 [pmc-release] AID - molecules25030585 [pii] AID - molecules-25-00585 [pii] AID - 10.3390/molecules25030585 [doi] PST - epublish SO - Molecules. 2020 Jan 29;25(3):585. doi: 10.3390/molecules25030585.