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1.
Wei Zhu Miaomiao Kang Qian Wu Zhijun Zhang Yi Wu Chunbin Li Kai Li Lei Wang Dong Wang Ben Zhong Tang 《Advanced functional materials》2021,31(3):2007026
Fluorescence imaging in the second near-infrared region (NIR-II) can penetrate tissue at centimeter depths and obtain high image fidelity. However, facile synthesis of small-molecule fluorescent photosensitizers for efficient NIR-II fluorescence imaging as well as photodynamic and photothermal combinatorial therapies is still a challenging task. Herein, a rational design and facile synthesis protocol are reported for a series of novel NIR-emissive zwitterionic luminogens with aggregation-induced emission (AIE) features for cancer phototheranostics. Consistent with the intrinsic features including long emission wavelength, effective reactive oxygen species generation, and excellent photothermal conversion efficiency (35.76%), in vitro and in vivo evaluation show that one of these presented AIE luminogens provides excellent performance in NIR-II fluorescence imaging-guided synergistic phototherapy against cancer. 相似文献
2.
Shen Tong Weilin Xu Jincheng Zhong Miaomiao Kang Xinlin Chen Yingxian Zhang Jie Huang Zhenhui Li Chi Zhang Zhiang Gao Weixin Xie Ping Qiu Zhijun Zhang Dong Wang Ke Wang 《Advanced functional materials》2023,33(46):2305521
Three-photon fluorescence (3PF) imaging excited at 1700 nm window is an enabling technology for visualizing deep brain structures and dynamics. Recently, the 2200 nm window has emerged as the longest excitation window suitable for deep-brain 3PF imaging. Bright fluorescent probes lay the material basis for deep-brain 3PF imaging. Among various fluorescent probes, aggregation-induced emission luminogens (AIEgens) have great potential in 3PF imaging excited at the 1700 nm window in vivo. However, to the best of knowledge, there is no AIEgens applicable to 3PF imaging excited at both the 1700 and 2200 nm windows. To readily fill this gap, here this study designs and synthesizes a novel AIEgen, namely TPE-DPTT-ICP, which generates bright 3PF signals excited at both 1700 and 2200 nm. The accordingly fabricated TPE-DPTT-ICP nanoparticles (NPs) possess excellent water dispersibility, colloidal stability, biocompatibility, photostability and large 3P action cross section, key to in vivo imaging. In mouse brain in vivo, TPE-DPTT-ICP NPs enable deep-brain 3PF imaging of subcortical structures excited at both the two windows, reaching depths of 1640 and 880 µm below the brain surface, respectively. TPE-DPTT-ICP NPs are thus a versatile material simultaneously catering to the need at two infrared optical windows with deep tissue penetration. 相似文献
3.
Shanliang Song Yue Zhao Miaomiao Kang Zhijun Zhang Qian Wu Shuang Fu Youmei Li Haifei Wen Dong Wang Ben Zhong Tang 《Advanced functional materials》2021,31(51):2107545
The ingenious construction of versatile cancer phototheranostics involving fluorescence imaging (FLI) and photodynamic and photothermal therapies (PDT, PTT) concurrently has attracted great interest. By virtue of their inherent twisted structures and plentiful motion moieties, aggregation-induced emission luminogens (AIEgens) have been proven to be perfect templates for the development of multimodal phototheranostic systems as their diverse energy consumption pathways can be flexibly regulated through tuning the intramolecular motions. Side-chain engineering is generally accepted as a useful regulation strategy for intramolecular motions through altering the side-chain structure of the molecule, but has rarely been reported for the construction of AIE-active multimodal phototheranostics. Herein, by taking full advantage of the side-chain engineering strategy, an AIE-active multifunctional phototheranostic system (TBFT2 nanoparticles) is successfully constructed by intentionally manipulating the length of side chains. Bearing the longest alkyl chain, all of those three energy dissipation pathways including radiative decay, nonradiative thermal deactivation, and intersystem crossing process of TBFT2 are retained simultaneously and controllably in the aggregate state. In vitro and in vivo evaluations verify that TBFT2 nanoparticles perform well in terms of FLI-guided PDT and PTT synergistic cancer therapy. This study thus provides new insight into the exploration of superior versatile phototheranostics through side-chain engineering. 相似文献
4.
用飞秒脉冲激光,研究了二氢卟吩光敏剂CPD3分子在双光子激发(TPE)下的光物理过程。报道了该分子在四氢呋喃(THF)溶剂中的TPE荧光光谱及其寿命,以及在波长800nm处的双光子吸收(TPA)截面,其中,TPE与单光子激发(OPE)的荧光光谱形状一致,具有相同的荧光发射带,荧光寿命分别为5.1ns和5.7ns;在波长800nm处的TPA截面σ2≈12.5×10-22cm4/GW。本文分析表明:在TPE下,该分子跃迁到激发态S2,经历了无辐射弛豫到达OPE的同一荧光能级,呈现激发Q带所产生的正常的荧光发射;该分子具有大的TPA截面是起源于该分子的刚性平面共轭结构所固有的线性吸收特性和TPA共振增强;CPD3作为光动力治疗(PDT)的光敏剂,又具有长波长的荧光发射、ns级的荧光寿命和大的TPA截面特性,这些双重特性使其有可能成为双光子荧光分子探针,借助于双光子荧光显微和成像技术,在分子水平上揭开PDT光敏药物与细胞器的结合特性和作用靶点等深层次问题。 相似文献
5.
Zheng Zheng Yuchen Yang Pingping Wang Xuexin Gou Junyi Gong Xiaoqian Wu Zhiwei Bao Lijie Liu Jing Zhang Hang Zou Lei Zheng Ben Zhong Tang 《Advanced functional materials》2023,33(35):2303627
The polarity of lipid droplets (LDs) plays an important role in pathological processes associated with abnormal lipid metabolism. Monitoring the variation of LDs polarity in cells and tissues is of great importance in biomedical research and clinical diagnosis. However, developing fluorescent LDs-specific probes with high polarity sensitivity, brightness, and permeability for deep tissue imaging is still challenging. Herein, a push–pull fluorescent luminogen (DPBT) with aggregation-induced emission, strong solvatochromism, large Stokes shift, high solid-state fluorescence efficiency and superior two-photon absorption is facilely developed. The lipophilic DPBT can specifically stain LDs with high biocompatibility and good photostability. The viscosity-enhanced solvatochromic emission property enables DPBT to visualize LDs polarity with high brightness and imaging contrast, and deep penetration depth under two-photon microscopy. DPBT can specifically stain lipids in various mouse tissues (atherosclerotic plaque, liver, and mesenteric adipose tissues) and map their polarity distribution to reflect lipid metabolic states within those tissues. It is found that the lipids deposition as well as their polarity distribution in tissues of hyperlipoidemia mouse are clearly different from the tissues of the normal mouse. Its excellent properties make DPBT a promising candidate for investigating LDs-associated physiological and pathological processes in live biological samples. 相似文献
6.
Shiyuan Hua Shuhan Zhong Hamed Arami Jian He Danni Zhong Dongxiao Zhang Xiaoying Chen Jun Qian Xinyang Hu Min Zhou 《Advanced functional materials》2021,31(24):2100468
Stem cell therapy has been used as a potential approach for the treatment of myocardial infarction (MI) over the last two decades. Imaging cellular behaviors of the transplanted stem cells with deep tissue penetration and high precision imaging modalities is crucial for the clinical translation of stem cell therapy approaches for MI. Herein, a gold nanostar (Au-Star) based second near-infrared window (NIR-II) fluorescence/surface enhanced Raman scattering dual-modal imaging probe (gold nanostar-3.3′-diethylthiatricarbocyanine iodide-silver sulfide nanoparticles, Au-Star-DTTC-Ag2S NPs, GDS NPs) is designed for labeling and precise tracking of the stem cells. The Ag2S compartment generates strong NIR-II emission, which compensates for the deficiencies of bioluminescent imaging and enables the dynamic observation of in vivo cellular behavior. Subsequently, the specific Raman signal of Au-Star-DTTC compartment enables high-resolution imaging, which could effectively delineate stem cells from the surrounding normal tissues, even at a single-cell resolution. Using this imaging and tracking approach, it is able to track stem cells in hypodermic and MI models, with high resolution and depth-independent imaging capabilities, which have not been reported in any other cell tracking platform. This two-armed imaging toolkit offers new opportunities for a wide range of mechanistic stem cell therapy investigations in different organs. 相似文献
7.
Caixia Sun Xiaofei Sun Peng Pei Haisheng He Jiang Ming Xuan Liu Minchao Liu Yuntong Zhang Yan Xia Dongyuan Zhao Xiaomin Li Yang Xie Fan Zhang 《Advanced functional materials》2021,31(23):2100656
Medical implants are widely used in clinical practice, such as cardiovascular stenting, maxillofacial surgery, and orthopedics. However, most of the traditional implant operations are open and invasive, resulting in massive dissection of soft tissue and interruption of blood supply. The accurate navigation for the implant operations is considered as one of the most effective ways to reduce the damage, which is urgently desired in clinic. Herein, a biocompatible NIR-II J-aggregates labelled mesoporous implant for imaging-guided osteosynthesis with minimal invasion is reported. Mesoporous silica layer with vertical channels is grown on the surface of titanium plate, which can provide the confining space for the formation of the FD-1080 J-aggregates. Both the absorption and fluorescence peaks of the FD-1080 J-aggregates are located in NIR-II window (beyond 1300 nm), which are ideal for high resolution and real time surgical navigation in deep tissue. NIR-II imaging can clearly display the location and outline of the implant both in vitro and in vivo. This NIR-II imaging-guided osteosynthesis can effectively reduce the surgical wound and operational duration, which is crucial for the implant surgeries. 相似文献
8.
Zhuqing Sun;Tuanwei Li;Feng Wu;Tingfeng Yao;Hongchao Yang;Xiaohu Yang;Hongqiang Yin;Yajuan Gao;Yejun Zhang;Chunyan Li;Qiangbin Wang; 《Advanced functional materials》2024,34(14):2311622
Photothermal therapy (PTT) is considered a promising treatment strategy for solid tumors. However, local hyperthermia (over 45°C) during PTT can cause severe side effects in neighboring healthy tissues. PTT with accurate temperature feedback is a compelling strategy to ablate tumors and reduce side effects, but it still faces challenges. Here, a new kind of phototheranostic nanoparticle, namely 17-RF@Ag2Se is developed, enabling in vivo NIR-II fluorescence tracking, PTT and fluorescence nanothermometry as well as synergistic heat-shock protein (HSP) inhibition. Precise PTT with high spatiotemporal resolution is achieved with the help of the designed NIR-II fluorescence imaging-photothermal therapy linkage apparatus. Upon intravenous injection, 17-RF@Ag2Se is specifically accumulated in tumors targeted by the overexpressed integrin αvβ3, which is monitored by NIR-II fluorescence imaging of Ag2Se QDs. Further, the release of HSP inhibitor, tanespimycin (17-AAG), enhances the thermosensitivity of tumor cells. Subsequently, the internal temperature of the tumor is precisely monitored and adjusted during PTT via the temperature-dependent NIR-II fluorescence feedback of Ag2Se QDs and the linkage apparatus calibration, thereby achieving efficient and safe tumor PTT. Also, the results present a new method for accurate temperature monitoring and control in vivo, which can be applied to other biomedical studies. 相似文献
9.
Zheng Lv Zhongwei Man Hongtu Cui Zhenzhen Xu Huanhuan Cao Shuai Li Qing Liao Qihua He Lemin Zheng Hongbing Fu 《Advanced functional materials》2021,31(10):2009329
Lysosomes and mitochondria play an important role in maintaining cell homeostasis. Visualizing the long-term activities of lysosomes and mitochondria on the nanometer scale in live cells is essential for further understanding their functions but remains challenging due to the limitations of existing fluorescent probes, such as aggregation-caused quenching (ACQ) effect, limited signal-to-noise ratio from fluorescence “always on” in the process of targeting organelle and poor photobleaching resistance. Herein, two efficient red-emitting aggregation-induced emission (AIE) luminogens are reported, which showed “off-on” fluorescence characteristic and specific lysosomes as well as mitochondria targeting capability. Owing to their AIE characteristics, a Stokes’ shift larger than 100 nm, good biocompatibility, and excellent photostability, the AIE luminogens have been successfully utilized for high fidelity imaging of lysosomes and mitochondria. By virtue of these two probes, stimulated emission depletion (STED) images of dynamic lysosomal fusion and mitochondrial fission with a high resolution of 65.6 nm are obtained. Furthermore, the interactions between lysosomes and mitochondria in the process of mitophagy are recorded. This study also provides practical guidance for designing specific organelle targeting probes to support live cell dynamic super-resolution imaging. 相似文献
10.
双光子荧光（two-photon fluorescence,TPF）显微成像技术借助荧光探针实现样品中被标记成分的特异性成像,具有天然的三维层析能力、高成像深度与空间分辨率、以及更小的光漂白与光损伤,已经发展成为化学、医药学和生命科学领域的一项重要研究工具。文中通过分析高斯光束复振幅在空间中的分布,推导出TPF信号的纵向与径向分布公式,以此估算出文中的TPF显微成像系统的横向分辨率为453 nm,纵向分辨率为2.087 μm。使用飞秒激光器作为激发光源,搭建了TPF显微成像系统。在800 nm波长的飞秒脉冲激发下,测量了罗丹明B溶液的TPF光谱,从而选择636~703 nm作为显微成像的荧光探测窗口。随后开展了对罗丹明B染色的小鼠大脑切片的TPF显微成像实验研究,利用断层扫描成像的方式获得了小鼠大脑切片在0~14 μm深度内的荧光强度分布。通过三维重构完成了对生物样品的三维立体成像,获得了小鼠大脑中灰质与白质在不同深度的分布情况,实验结果证明了搭建的显微成像系统具有优异的成像深度与空间分辨能力。 相似文献
11.
Yuanyuan Li Jianquan Zhang Shunjie Liu Chen Zhang Clarence Chuah Youhong Tang Ryan T. K. Kwok Jacky W. Y. Lam Hanlin Ou Dan Ding Ben Zhong Tang 《Advanced functional materials》2021,31(29):2102213
Although organic materials with near infrared (NIR)-II fluorescence and a photothermal effect have been widely investigated for the accurate diagnosis and treatment of tumors, optimizing the output signals of both remain challenging. Here, a strategy by “enlarging absorption reservoir” to address this issue, since an increase in photon absorption can naturally enhance output signals, is proposed. As a proof-of-concept, a large π-conjugated diketopyrrolopyrrole (DPP) unit is selected to fabricate strong light-absorbing systems. To enhance solid-state fluorescence, highly twisted alkylthiophene–benzobisthiadiazole–alkylthiophene and triphenylamine rotor are introduced to restrict the strong intermolecular π–π interactions. Moreover, the number of DPP units in molecules is engineered to optimize photophysical properties. Results show that TDADT with two DPP units possesses an exceptionally high molar absorptivity of 2.1 × 105 L mol−1 cm−1 at 808 nm, an acceptable NIR-II quantum yield of 0.1% (emission peak at 1270 nm), and a sizeable photothermal conversion efficiency of 60.4%. The excellent photophysical properties of the TDADT nanoparticles are particularly suitable for in vivo NIR-II imaging-guided cancer surgery and NIR-I photothermal therapy. The presented strategy provides a new approach of designing highly efficient NIR-II phototheranostic agents. 相似文献
12.
双光子荧光显微成像技术具有较低的光漂白与光损伤、较佳的成像对比度、较深的穿透深度等优点。采用结扎大鼠冠状动脉左前降支的方法建立急性心肌缺血模型,通过双光子荧光显微成像技术获得不同结扎时间下大鼠左心室前壁心肌组织的双光子荧光图像。从中分析了不同结扎时间下心肌组织的形态学变化,实现对心肌组织损伤范围的确定;并对双光子荧光图像进行快速傅里叶变换(FFT),使用方向指数这一参数对心肌缺血的程度进行初步的量化评估。结果表明,双光子荧光显微成像技术结合FFT分析技术,有望在心肌缺血性疾病的诊断和治疗中实时、快速、准确地判断心肌缺血的范围和评估其损伤程度。 相似文献
13.
近年来,神经细胞中快速荧光信号的随机三维成像成为研究的热点问题,对双光子荧光显微成像系统中轴向扫描速度提出了更高的要求。本文设计一种快速轴向扫描系统,通过电致位移驱动器件,驱动显微物镜中靠近样品端的聚焦透镜组,实现物镜前焦点在轴向的快速扫描。系统中由少数透镜组成的聚焦透镜组与主透镜组之间为近平行光路,适应大范围扫描;聚焦透镜组质量轻、驱动器负载小、扫描速度快。用ZEMAX软件对系统进行仿真分析,结果表明:当扫描深度从0～500 μm变化时系统MTF曲线变化很小。聚焦透镜组重量仅有0.1 g,以压电陶瓷作为位移驱动元件可达到千赫兹量级的扫描频率,能够满足神经功能成像的大范围和快速轴向扫描要求。 相似文献
14.
Chao Yin Hua Zhang Bo Sun Shangyu Chen Xinyue Jiang Xiaofei Miao Pengfei Sun Wenbo Hu Quli Fan Wei Huang 《Advanced functional materials》2021,31(47):2106575
Exploration of high-efficiency agents for near-infrared-II fluorescence imaging (NIR-II FI) promotes the development of NIR-II FI in life science. Despite the extensive use of organic semiconducting nanomaterials for NIR-II FI, the fluorescence efficiency is barely satisfying, and the molecular guideline to improve the imaging quality has not been clarified yet. This contribution designs self-brightened organic semiconducting polymers (OSPs) for improved NIR-II phototheranostics of cancer. The amplification of NIR-II brightness is realized by incorporating a weak electron-donating unit (5,5′-dibromo-4,4′-didodecyl-2,2′-bithiophene, DDB) into the semiconducting backbone with strong electron donor–acceptor alternated structure, which exhibits 6.3-fold and 25-fold fluorescence enhancement compared with the counterpart OSP at the same optical concentration and mass concentration, respectively. The broadband femtosecond transient absorption spectra experimentally elucidate the DDB doping-induced suppression of vibrational relaxation as the underlying reason for the NIR-II fluorescence amplification. Biocompatible nanoparticles fabricated from the optimal OSP12 exhibit excellent NIR-II phototheranostic performance both in vitro and in vivo. Our research not only reveals the mechanistic insights for fluorescence enhancement of the designed OSPs from the essential view but also highlights an effective molecular methodology to guide the rational design of imaging agents with enhanced NIR-II brightness for improved phototheranostics in living subjects. 相似文献
15.
Sitong Wu;Zhichao Yang;Chenguang Ma;Xun Zhang;Chao Mi;Jiajia Zhou;Zhiyong Guo;Dayong Jin 《光电进展（英文版）》2023,6(4):220105-1-220105-9
Fluorescence imaging through the second near-infrared window (NIR-II,1000–1700 nm) allows in-depth imaging. However, current imaging systems use wide-field illumination and can only provide low-contrast 2D information, without depth resolution. Here, we systematically apply a light-sheet illumination, a time-gated detection, and a deep-learning algorithm to yield high-contrast high-resolution volumetric images. To achieve a large FoV (field of view) and minimize the scattering effect, we generate a light sheet as thin as 100.5 μm with a Rayleigh length of 8 mm to yield an axial resolution of 220 µm. To further suppress the background, we time-gate to only detect long lifetime luminescence achieving a high contrast of up to 0.45 Ιcontrast. To enhance the resolution, we develop an algorithm based on profile protrusions detection and a deep neural network and distinguish vasculature from a low-contrast area of 0.07 Ιcontrast to resolve the 100 μm small vessels. The system can rapidly scan a volume of view of 75 × 55 × 20 mm3 and collect 750 images within 6 mins. By adding a scattering-based modality to acquire the 3D surface profile of the mice skin, we reveal the whole volumetric vasculature network with clear depth resolution within more than 1 mm from the skin. High-contrast large-scale 3D animal imaging helps us expand a new dimension in NIR-II imaging. 相似文献
16.
Chenlu Wang Hongxin Lin Xiaoguang Ge Jing Mu Lichao Su Xuan Zhang Meng Niu Huanghao Yang Jibin Song 《Advanced functional materials》2021,31(16):2009942
Detection of glutathione (GSH) in the body is essential to accurately map the redox state of cells and real-time visualization of physiological and pathological conditions in vivo. However, traditional fluorescence (FL) imaging in the near-infrared I region (NIR-I, 650–900 nm) is difficult to quantitively visualize GSH in vivo due to the tissue autofluorescence background and disastrous photon scattering. Herein, a NIR-IIb (1500–1700 nm) nanoprobe consisting of 4-nitrophenol-Cy7 (NPh) conjugated lanthanide-based downconversion nanoparticles (DCNP@NPh-PEG) is developed for in vivo ratiometric imaging of GSH. In the presence of GSH, NPh shows responsively enhanced FL emission at 808 nm, thus enhancing FL signal at 1550 nm of DCNPs excited by 808 nm (F1550, 808Ex) through non-radiative energy transfer (NRET) effect, while the fluorescence of DCNP at 1550 nm excited by 980 nm laser (F1550, 980Ex) is stable because no NRET occurred. The ratiometric F1550, 980Ex/F1550, 808Ex value exhibits a linearship with GSH concentration ranged from 0–24 mm with detection limit of 0.3 mm . The NIR-IIb nanoprobe has excellent performance in detecting and imaging GSH in both subcutaneous tumor and orthotopic colon tumor in vivo with high accuracy and resolution. The design strategy of the ratiometric NIR-II FL nanoprobe based on the activated FERT effect provides a reliable tool for the development of NIR-II nanoprobes for accurate biosensing in vivo. 相似文献
17.
Weiguo Qiao Teng Ma Shuangshuang Wang Longjie Li Miao Liu Hao Jiang Yuzhou Wu Jintao Zhu Zhong'an Li 《Advanced functional materials》2021,31(45):2105452
Development of ratiometric fluorescent hypochlorite probes with strong long wavelength fluorescence in aqueous medium, high resistance to photobleaching, high sensitivity and selectivity, and low biological toxicity remains a challenge. In this work, a molecular design strategy is proposed that can transform the traditional squaraine dyes (SQs) with aggregation-caused quenching character into aggregation-induced emission (AIE)-active luminogens by functionalizing the end-groups with tetraphenylethylene units and further introducing hydrophilic sulfonate group as the side chains. The resulting TPE-SQ5 not only emits strong deep-red fluorescence with a high quantum yield of 11.0% and high photostability, but more encouragingly can serve as a ratiometric fluorescent hypochlorite probe with high selectivity and sensitivity (detection limit: 5.6 nm ), which indeed is the first report for SQs. The detailed sensing mechanism study demonstrates that the oxindole product with sulfonate substitution is responsible for the ratiometric fluorescent response. Furthermore, TPE-SQ5 nanoparticles with high biocompatibility and low cytotoxicity are successfully used for ratiometrically imaging exogenous and endogenous hypochlorite in living cells. 相似文献
18.
Guowei Chen Jianghui Wang Wen-Cheng Chen Yarong Gong Ning Zhuang Hui Liang Longjiang Xing Yuan Liu Shaomin Ji Hao-Li Zhang Zujin Zhao Yanping Huo Ben Zhong Tang 《Advanced functional materials》2023,33(12):2211893
Multiple-resonance (MR) thermal activated delayed fluorescence (TADF) emitters have attracted increasing attention in organic electroluminescence devices, owing to their superior quantum efficiency and narrowband emission for high color purity. However, MR-TADF materials often suffer from severe aggregation-caused quenching (ACQ) and efficiency roll-off problems due to their rigid planar structures and the lack of sufficient charge-transfer (CT) characters with inefficient reverse intersystem crossing (RISC). Herein, by attaching electron-rich triphenylamine (TPA) with twisted spatial conformation to the MR framework, two efficient narrowband MR-TADF emitters, namely BNCz-pTPA and BNCz-mTPA , are developed. The TPA substituent endows the new emitters with aggregation-induced emission enhancement (AIEE) for ACQ suppression. The unprecedented AIEE-MR-TADF emitters exhibit CT character in high-lying triplet excited states for faster RISC, while the locally-excited (LE) character of the first singlet excited state is retained for narrowband emission with high emission efficiency. An organic light-emitting diode (OLED) based on BNCz-pTPA exhibits a maximum external quantum efficiency of 27.3% with slow efficiency roll-off, demonstrating much higher performances than those of the BNCz -based OLED. This study may provide a simple but effective approach to constructing high-performance emitters for wide-color-gamut OLED displays. 相似文献
19.
Ji-Yu Zhu Alexander Mikhailovsky Samuel Chan Jun Wei Alex Moreland Jakkarin Limwongyut Nekane Guarrotxena Guillermo C. Bazan 《Advanced functional materials》2023,33(42):2305962
Conjugated oligoelectrolytes (COEs) comprise a class of cell-membrane intercalating molecules that serve as effective optical reporters. However, little is known about the photophysical properties of COEs in biological environments such as buffers, cell membranes, and intracellular organelles, which is critical to optimize performance. Herein, how COE self-assembly depends on the dielectric environment (polarity and ion content) is explored based on the representative molecule 6-ring phenylenevinylene (PV) conjugated oligoelectrolyte (COE-S6), and its optical properties within mammalian cells are subsequently studied. Two-photon fluorescence lifetime imaging microscopy (FLIM), confocal laser scanning microscopy, and optical properties in solutions are brought together to obtain information about the location, accumulation, and characteristics of the local surroundings. FLIM imaging lifetime phasor plots, decays, and fluorescence spectra on stained mammalian cells provide evidence of successful COE-S6 internalization via endocytosis. The fluorescence lifetime of COE-S6 is identical when in A549 mammalian cells and in giant unilamellar vesicle model membranes, thereby providing a correlation between living system and artificial constructs. 相似文献
20.
Hyung Jong Kim Hyunchul Kang Ji-Eun Jeong Su Hong Park Chang Woo Koh Chai Won Kim Han Young Woo Min Ju Cho Sungnam Park Dong Hoon Choi 《Advanced functional materials》2021,31(33):2102588
Ultra-deep-blue aggregation-induced delayed fluorescence (AIDF) emitters (TB-tCz and TB-tPCz) bearing organoboron-based cores as acceptors and 3,6-substituted carbazoles as donors are presented. The thermally activated delayed fluorescence (TADF) properties of the two emitters are confirmed by theoretical calculations and time-resolved photoluminescence experiments. TB-tCz and TB-tPCz exhibit fast reverse intersystem crossing rate constants owing to efficient spin–orbit coupling between the singlet and triplet states. When applied in solution-processed organic light-emitting diodes (OLEDs), the TB-tCz- and TB-tPCz-based nondoped devices exhibit ultra-deep-blue emissions of 416–428 nm and high color purity owing to their narrow bandwidths of 42.2–44.4 nm, corresponding to the Commission International de l´Eclairage color coordinates of (x = 0.16–0.17, y = 0.05–0.06). They show a maximum external quantum efficiency (EQEmax) of 8.21% and 15.8%, respectively, exhibiting an unprecedented high performance in solution-processed deep-blue TADF-OLEDs. Furthermore, both emitters exhibit excellent device performances (EQEmax = 14.1–15.9%) and color purity in solution-processed doped OLEDs. The current study provides an AIDF emitter design strategy to implement high-efficiency deep-blue OLEDs in the future. 相似文献