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91.
Synthesis and Design of Aggregation‐Induced Emission Surfactants: Direct Observation of Micelle Transitions and Microemulsion Droplets 下载免费PDF全文
Dr. Weijiang Guan Dr. Wenjuan Zhou Prof. Dr. Chao Lu Prof. Dr. Ben Zhong Tang 《Angewandte Chemie (International ed. in English)》2015,54(50):15160-15164
The direct visualization of micelle transitions is a long‐standing challenge owing to the intractable aggregation‐caused quenching of light emission in the micelle solution. Herein, we report the synthesis of a surfactant with a tetraphenylethene (TPE) core and aggregation‐induced emission (AIE) characteristics. The transition processes of surfactant micelles and the microemulsion droplets (MEDs) formed by the surfactant with a TPE core were clearly visualized by a high‐contrast fluorescence imaging method. The fluorescence intensity of the MEDs decreased as the size of MEDs increased as a result of weakening of the restriction of intramolecular rotation (RIR). The results of this study deepen our understanding of micelle‐transition processes and provide solid evidence in favor of the hypothesis that the AIE phenomenon has its origin in the RIR of fluorophores in the aggregate state. 相似文献
92.
Rare Earth Ion Mediated Fluorescence Accumulation on a Single Microbead: An Ultrasensitive Strategy for the Detection of Protein Kinase Activity at the Single‐Cell Level 下载免费PDF全文
Xiaobo Zhang Prof. Dr. Chenghui Liu Honghong Wang Hui Wang Prof. Dr. Zhengping Li 《Angewandte Chemie (International ed. in English)》2015,54(50):15186-15190
A single microbead‐based fluorescence imaging (SBFI) strategy that enables detection of protein kinase activity from single cell lysates is reported. We systematically investigated the ability of various rare earth (RE) ions, immobilized on the microbead, for specific capturing of kinase‐induced phosphopeptides, and Dy3+ was found to be the most prominent one. Through the efficient concentration of kinase‐induced fluorescent phosphopeptides on a Dy3+‐functionalized single microbead, kinase activity can be detected and quantified by reading the fluorescence on the microbead with a confocal fluorescence microscope. Owing to the extremely specific recognition of Dy3+ towards phosphopeptides and the highly‐concentrated fluorescence accumulation on only one microbead, ultrahigh sensitivity has been achieved for the SBFI strategy which allows direct kinase analysis at the single‐cell level. 相似文献
93.
High‐contrast Noninvasive Imaging of Kidney Clearance Kinetics Enabled by Renal Clearable Nanofluorophores 下载免费PDF全文
Dr. Mengxiao Yu Dr. Jinbin Liu Xuhui Ning Prof. Dr. Jie Zheng 《Angewandte Chemie (International ed. in English)》2015,54(51):15434-15438
Noninvasive imaging of kidney clearance kinetics (KCK) of renal clearable probes is key to studying unilateral kidney function diseases, but such imaging is highly challenging to achieve with in vivo fluorescence. While this long‐standing challenge is often attributed to the limited light penetration depth, we found that rapid and persistent accumulation of conventional dyes in the skin “shadowed” real fluorescence signals from the kidneys and prevented noninvasive imaging of KCK, which, however, can be addressed with renal clearable nanofluorophores. By integrating near infrared emission with efficient renal clearance and ultralow background interference, the nanofluorophores can increase kidney‐contrast enhancement and imaging‐time window by approximately 50‐ and 1000‐fold over conventional dyes, and significantly minimize deviation between noninvasive and invasive KCK, laying down a foundation for translating in vivo fluorescence imaging in preclinical noninvasive kidney function assessments. 相似文献
94.
The Contrasting Recognition Behavior of β‐Cyclodextrin and Its Sulfobutylether Derivative towards 4′,6‐Diamidino‐2‐phenylindole 下载免费PDF全文
Meenakshi N. Shinde Dr. Achikanath C. Bhasikuttan Dr. Jyotirmayee Mohanty 《Chemphyschem》2015,16(16):3425-3432
The noncovalent interactions between 4′, 6‐diamidino‐2‐phenylindole (DAPI) and sulfobutylether β‐cyclodextrin (SBE7β‐CD) are evaluated by using photochemical measurements and compared with that of native β‐CD. Contrasting recognition behavior and intriguing modulations in the photochemical behavior of DAPI were observed. In particular, a large enhancement in the fluorescence emission and excited‐state lifetime were seen upon binding to SBE7β‐CD, with the SBE7β‐CD inclusion complex being approximately 1000 times stronger than that of β‐CD. The ensuing fluorescence “turn on” was demonstrated to be responsive to chemical stimuli, such as metal ions and adamantylanmine (AD). Upon addition of Ca2+/AD, nearly quantitative dissociation of the complex was established to regenerate the free dye and result in fluorescence “turn off”. The SO3? groups are believed to be critical for the strong and selective binding of the chromophore and the stimuli‐responsive tuning. This is as an important design criterion for the optimization of host–guest properties through supramolecular association, which is relevant for drug‐delivery applications. 相似文献
95.
Effect of Controlled Deposition of ZnS Shell on the Photostability of CdTe Quantum Dots as Studied by Conventional Fluorescence and FCS Techniques
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The effect of one and two monolayers of ZnS shells on the photostability of CdTe quantum dots (QDs) in aqueous and nonaqueous media has been studied by monitoring the fluorescence behavior of the QDs under ensemble and single‐molecule conditions. ZnS capping of the CdTe QDs leads to significant enhancement of the fluorescence brightness of these QDs. Considerable enhancement of the photostability of the shell‐protected QDs, including the suppression of photoactivation, is also observed. Fluorescence correlation spectroscopy measurements reveal an increase in the number of particles undergoing reversible fluorescent on–off transitions in the volume under observation with increasing excitation power; this effect is found to be more pronounced in the case of core‐only QDs than for core–shell QDs. 相似文献
96.
Iron(III)‐Selective Chelation‐Enhanced Fluorescence Sensing for In Vivo Imaging Applications 下载免费PDF全文
Lin E. Guo Xin Yi Liu Huan Wang Qiu Ling Chen Guang Ke Wang Prof. Kaijun Luo Qi Li Mi Prof. Ying Zhou Jun Feng Zhang 《化学:亚洲杂志》2015,10(9):1898-1902
A “turn‐on” pattern Fe3+‐selective fluorescent sensor was synthesized and characterized that showed high fluorescence discrimination of Fe3+ over Fe2+ and other tested ions. With a 62‐fold fluorescence enhancement towards Fe3+, the probe was employed to detect Fe3+ in vivo in HeLa cells and Caenorhabditis elegans, and it was also successfully used to elucidate Fe3+ enrichment and exchange infected by innexin3 (Inx3) in hemichannel‐closed Sf9 cells. 相似文献
97.
Dual Functioning Thieno‐Pyrrole Fused BODIPY Dyes for NIR Optical Imaging and Photodynamic Therapy: Singlet Oxygen Generation without Heavy Halogen Atom Assistance 下载免费PDF全文
Dr. Ryan L. Watley Dr. Samuel G. Awuah Dr. Moses Bio Robert Cantu Habtom B. Gobeze Dr. Vladimir N. Nesterov Dr. Sushanta K. Das Prof. Dr. Francis D'Souza Prof. Dr. Youngjae You 《化学:亚洲杂志》2015,10(6):1335-1343
We discovered a rare phenomenon wherein a thieno‐pyrrole fused BODIPY dye (SBDPiR690) generates singlet oxygen without heavy halogen atom substituents. SBDPiR690 generates both singlet oxygen and fluorescence. To our knowledge, this is the first example of such a finding. To establish a structure–photophysical property relationship, we prepared SBDPiR analogs with electron‐withdrawing groups at the para‐position of the phenyl groups. The electron‐withdrawing groups increased the HOMO–LUMO energy gap and singlet oxygen generation. Among the analogs, SBDPiR688, a CF3 analog, had an excellent dual functionality of brightness (82290 m ?1 cm?1) and phototoxic power (99170 m ?1 cm?1) comparable to those of Pc 4, due to a high extinction coefficient (211 000 m ?1 cm?1) and balanced decay (Φflu=0.39 and ΦΔ=0.47). The dual functionality of the lead compound SBDPiR690 was successfully applied to preclinical optical imaging and for PDT to effectively control a subcutaneous tumor. 相似文献
98.
Luminescent Nanofibers Fabricated from Phenanthroimidazole Derivatives by Organogelation: Fluorescence Response towards Acid with High Performance 下载免费PDF全文
Jiang Peng Dr. Jingbo Sun Peng Gong Dr. Pengchong Xue Zhenqi Zhang Gonghe Zhang Prof. Ran Lu 《化学:亚洲杂志》2015,10(8):1717-1724
Nanofibers based on phenanthroimidazole derivatives PCC , PDC , and PSC were fabricated by organogelation processes, and their fluorescence sensory properties towards acid were investigated. It was found that the emission of PCC in the nanofiber‐based film could be quenched significantly upon exposure to gaseous TFA due to the formation of protonated PCC , in which ICT (intramolecular charge transfer) would occur. On the other hand, TFA vapor led to the emitting colors of PDC and PSC in the nanofiber‐based films to turn to yellow and green from sky blue and blue, respectively. Additionally, we found that the decay times of PCC were 0.1 s and 1.9 s in probing the saturated vapor of TFA in nanofiber‐based film and in spin‐coated film, respectively. The results suggested that the high surface‐to‐volume ratio and large interspace in the nanofiber‐based networks favored the enhanced adsorption, accumulation, and diffusion of gaseous molecules, resulting in such a high performance. 相似文献
99.
Xu Zhang Lei Zhang Meng‐Jie Wang Kou‐Lin Zhang 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(9):776-782
Two new coordination polymers (CPs) formed from 5‐iodobenzene‐1,3‐dicarboxylic acid (H2iip) in the presence of the flexible 1,4‐bis(1H‐imidazol‐1‐yl)butane (bimb) auxiliary ligand, namely poly[[μ2‐1,4‐bis(1H‐imidazol‐1‐yl)butane‐κ2N3:N3′](μ3‐5‐iodobenzene‐1,3‐dicarboxylato‐κ4O1,O1′:O3:O3′)cobalt(II)], [Co(C8H3IO4)(C10H14N4)]n or [Co(iip)(bimb)]n, (1), and poly[[[μ2‐1,4‐bis(1H‐imidazol‐1‐yl)butane‐κ2N3:N3′](μ2‐5‐iodobenzene‐1,3‐dicarboxylato‐κ2O1:O3)zinc(II)] trihydrate], {[Zn(C8H3IO4)(C10H14N4)]·3H2O}n or {[Zn(iip)(bimb)]·3H2O}n, (2), were synthesized and characterized by FT–IR spectroscopy, thermogravimetric analysis (TGA), solid‐state UV–Vis spectroscopy, single‐crystal X‐ray diffraction analysis and powder X‐ray diffraction analysis (PXRD). The iip2− ligand in (1) adopts the (κ1,κ1‐μ2)(κ1, κ1‐μ1)‐μ3 coordination mode, linking adjacent secondary building units into a ladder‐like chain. These chains are further connected by the flexible bimb ligand in a trans–trans–trans conformation. As a result, a twofold three‐dimensional interpenetrating α‐Po network is formed. Complex (2) exhibits a two‐dimensional (4,4) topological network architecture in which the iip2− ligand shows the (κ1)(κ1)‐μ2 coordination mode. The solid‐state UV–Vis spectra of (1) and (2) were investigated, together with the fluorescence properties of (2) in the solid state. 相似文献
100.
Enhanced Fluorescence Imaging and Photodynamic Cancer Therapy Using Hollow Mesoporous Nanocontainers
《化学:亚洲杂志》2017,12(14):1700-1703
Here we show that “off‐on” type of photodynamic therapy agents could be developed using hollow mesoporous silica nanoparticles (HMSNPs), which can be used not only for enhancing delivery of photosensitizers to cancer cells but also for enabling switchable optical properties of the photosensitizers. Fluorescence and singlet oxygen generation of the photosensitizer‐loaded HMSNP are turned off in its native state. In vitro cell studies showed that this HMSNP‐based “off‐on” agent may have potential utility in selective fluorescence detection and photodynamic therapy of cancers. 相似文献