共查询到19条相似文献,搜索用时 306 毫秒
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《影像科学与光化学》2017,(6)
三苯基膦(简称PPh3)是一种重要的有机物质并有独特的亲核性和还原性,广泛应用于有机及有机金属物质的合成。PPh3的广泛使用不可避免地导致对环境的污染,给人类的健康带来危害,因此,亟需一种简单高效的检测手段实现对三苯基膦的检测识别。在本工作中,我们效仿Staudinger连接反应设计合成了一个具有高选择性和高灵敏度的荧光增强型探针用以检测三苯基膦。探针的设计思想是使用荧光素的邻叠氮苯乙酯衍生物与PPh3反应,通过生成的氮杂叶立德,经由分子内酰基转移释放荧光团。该探针在含0.5%的DMSO水溶液中显示对PPh3的高选择性响应,可望在线性范围1×10-7 mol/L至8×10-7 mol/L之间实现对PPh3的定量检测,其检测极限达到10nmol/L。对PPh3的灵敏检测可达到在水溶液中肉眼可视。 相似文献
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三苯基膦(简称PPh3)是一种重要的有机物质并有独特的亲核性和还原性,广泛应用于有机及有机金属物质的合成.PPh3的广泛使用不可避免地导致对环境的污染,给人类的健康带来危害,因此,亟需一种简单高效的检测手段实现对三苯基膦的检测识别.在本工作中,我们效仿Staudinger连接反应设计合成了一个具有高选择性和高灵敏度的荧光增强型探针用以检测三苯基膦.探针的设计思想是使用荧光素的邻叠氮苯乙酯衍生物与PPh3反应,通过生成的氮杂叶立德,经由分子内酰基转移释放荧光团.该探针在含0.5%的DMSO水溶液中显示对PPh3的高选择性响应,可望在线性范围1×10-7 mol/L至8×10-7 mol/L之间实现对PPh3的定量检测,其检测极限达到10 nmol/L.对PPh3的灵敏检测可达到在水溶液中肉眼可视. 相似文献
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螺旋桨结构的三苯胺荧光团既能作为强的电子供体,又能作为潜在的聚集诱导发光(AIE)骨架.同时,三苯胺衍生物很容易通过简单的反应进行结构修饰,如醛基、氨基、硼酸基、卤素、乙炔基等取代的三苯胺能够发生缩合反应或偶联反应等,进一步功能化.因此,功能性三苯胺类化合物被广泛用于太阳能电池、荧光染料、固态发光材料和荧光探针的分子设计中.根据三苯胺基荧光探针的检测对象,将其分为阳离子、阴离子和中性小分子荧光探针三类,并从分子的结构和性能出发,重点综述了近五年来国内外三苯胺基荧光探针在分子设计、合成与检测应用方面的最新进展.展望未来,构建近红外发光和高量子效率的AIE荧光探针值得关注. 相似文献
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近年来,荧光成像技术为人们研究活体细胞及组织内的化学生物学过程提供了有效的研究工具,可以无损、实时、原位地以高时空分辨率实现对目标物进行生物荧光成像与分析。荧光成像技术在生物学、环境监测、临床诊断和药物发现等诸多研究领域发挥着越来越重要的作用。生物荧光成像技术的最新进展对发展新型小分子荧光染料及探针提出了更高的要求。激发和发射波长位于近红外光区(600~900 nm)的荧光染料及探针由于具有光毒性低、生物分子自发荧光干扰小、光散射低、组织穿透能力强等优点,非常适合用于生物荧光成像领域。通过将罗丹明分子中O桥原子用Si代替,得到了一类新型的探针分子--硅杂蒽类荧光探针。这类染料分子在保留了氧杂蒽荧光染料优越的光学性质的同时,光谱发生明显红移,满足了近红外荧光检测的要求,具有良好的生物相容性。本文综述了近年来基于硅杂蒽及其衍生物荧光探针的合成及在金属离子、pH值、小分子、生物酶等检测方面的研究进展,并且简要阐述了基于硅杂蒽类探针分子的识别检测机理以及其在生物成像等方面的应用。 相似文献
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金属配合物因其优异的光物理性质,如配位结构可调、好的光稳定性、大的斯托克位移、高的荧光量子产率与长的荧光寿命等, 在生物成像、分子探针、医学影像等领域中备受关注。与单光子吸收相比,双光子吸收的金属配合物因其具有更加优秀的深度分辨率以及低光损伤性等优点,近些年被广泛应用于生物分子的荧光探针和细胞器染料等。本文综述了近年来具有双光子吸收的金属配合物对生物分子(如pH、O2、HClO、NO、SO2、GSH、DNA等)的响应检测用于疾病的诊断,以及作为细胞器(如线粒体、溶酶体、脂滴、细胞核等)染料探针用于细胞内动态行为和演化过程的实时示踪研究。最后,针对金属配合物在生物分子探针以及细胞器染料等方面的应用前景进行了分析和探讨。 相似文献
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《化学通报》2015,(12)
金属离子广泛存在于自然界中,一些离子如Cu2+、Fe3+、Al3+等在生命过程中有着重要作用,而另一些离子如Hg2+、Pb2+等重金属离子即使在低浓度时也会对环境和生物体具有极强的毒性,故高选择性和高灵敏度的离子检测的研究意义重大。荧光分子探针在表达分子间识别行为以及复杂的环境、生命体系的内状态信息方面具有优异的性能,已被广泛深入地用于构建新型功能性探针分子。本文综述了近年来基于若丹明的金属阳离子如Hg2+、Cu2+、Fe3+等荧光分子探针的研究进展,包括探针的结构特征、检测机理、检测水平,更重要的是其在环境检测、生物成像、分子器件等方面的新应用,并对荧光探针所面临的问题和发展前景作了分析。 相似文献
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Klymchenko AS Stoeckel H Takeda K Mély Y 《The journal of physical chemistry. B》2006,110(27):13624-13632
Development of fast-response potentiometric probes for measuring the transmembrane potential Vm in cell plasma membranes remains a challenge. To overcome the limitations of the classical charge-shift potentiometric probes, we selected a 3-hydroxychromone fluorophore undergoing an excited-state intramolecular proton transfer (ESIPT) reaction that generates a dual emission highly sensitive to electric fields. To achieve the highest sensitivity to the electric field associated to Vm, we modified the fluorophore by adding two rigid legs containing terminal polar sulfonate groups to allow a deep vertical insertion of the fluorophore into the membrane. Fluorescence spectra of the new dye in lipid vesicles and cell membranes confirm the fluorophore location in the hydrophobic region of the membranes. Variation of Vm in lipid vesicles and cell plasma membranes results in a change of the intensity ratio of the two emission bands of the probe. The ratiometric response of the dye in cells is approximately 15% per 100 mV, and is thus quite large in comparison with most single-fluorophore, fast-response probes reported to date. Combined patch-clamp/fluorescence data further show that the ratiometric response of the dye in cells is faster than 1 ms. Analysis of the excitation and emission shifts further suggests that the probe responds to changes in Vm by a mechanism based on electrochromic modulation of its ESIPT reaction. Thus, for the first time, the ESIPT reaction has been successfully applied as a sensing principle for detection of transmembrane potential, allowing to couple classical electrochromic band shifts with changes in the relative intensities of the two well-separated emission bands. The fast two-band ratiometric response as well as the relatively high sensitivity of the new probe are the key features that make it useful for rapid detection of Vm changes in cell suspensions and single cells. Moreover, the new design principles proposed in the present work should allow further improvement of the probe sensitivity. 相似文献
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Libo Hu 《Tetrahedron》2007,63(38):9387-9392
The effect of microwave irradiation on the selectivity, especially stereoselectivity, is one of the most important issues in microwave-assisted organic reactions. The diastereoselectivity in Staudinger reactions involving the representative ketenes and the corresponding matched imines has been used as a probe to investigate carefully the existence of the specific nonthermal microwave effects. The results indicate that the microwave irradiation-controlled stereoselectivity in the Staudinger reaction is in fact the contribution of temperature. No specific nonthermal microwave effect was found in the Staudinger reaction. 相似文献
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A highly selective fluorescent probe (OHBT) was designed and synthesized by linking the ESIPT fluorophore N-(3-(benzo[d]thiazol-2-yl)-4-(hydroxyphenyl) benzamide) (HBTBC) to the palladium specificity response group, allyl group, for the detection of palladium species in aqueous solution. The allyl group can be hydrolyzed by Pd0 species through the Pd0-catalyzed Tsuji–Trost reaction and thus release the fluorophore HBTBC, which shows two emission bands. The maximum emission spectra originated from the enol and keto forms at 415 and 555 nm respectively and with no overlap, which implies the high resolution of the palladium detection. The palladium species can also be detected by paper strip because of the solid-state fluorescence of probe HOBT catalyzed by palladium. This method was successfully applied in the palladium related Suzuki–Miyaura coupling reaction and the detection limit is lower than 1 μM. 相似文献
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Highly sequence specific and sensitive detection systems for DNA or RNA in vivo would be of great use in biology and medicine for monitoring gene expression and diagnosing diseased cells. Herein we describe a new nucleic acid-triggered fluorescent probe system that is activated by a biocompatible and chemoselective Staudinger reaction. 相似文献
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Junyang Zhuang Libing FuMingdi Xu Huanghao YangGuonan Chen Dianping Tang 《Analytica chimica acta》2013
Methods based on metal nanotags have been developed for metallobioassay of nucleic acids, but most involve complicated labeling or stripping procedures and are unsuitable for routine use. Herein, we report the proof-of-concept of a novel and label-free metallobioassay for ultrasensitive electronic determination of human immunodeficiency virus (HIV)-related gene fragments at an ultralow concentration based on target-triggered long-range self-assembled DNA nanostructures and DNA-based hybridization chain reaction (HCR). The signal is amplified by silver nanotags on the DNA duplex. The assay mainly consists of capture probe, detection probe, and two different DNA hairpins. In the presence of target DNA, the capture probe immobilized on the sensor sandwiches target DNA with the 3′ end of detection probe. Another exposed part of detection probe at the 5′ end opens two alternating DNA hairpins in turn, and propagates a chain reaction of hybridization events to form a nicked double-helix. Finally, numerous silver nanotags are immobilized onto the long-range DNA nanostructures, each of which produces a strong electronic signal within the applied potentials. Under optimal conditions, the target-triggered long-range DNA nanostructures present good electrochemical behaviors for the detection of HIV DNA at a concentration as low as 0.5 fM. Importantly, the outstanding sensitivity can make this approach a promising scheme for development of next-generation DNA sensors without the need of enzyme labeling or fluorophore labeling. 相似文献
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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(40):12285-12289
We report a fast Staudinger reaction between perfluoroaryl azides (PFAAs) and aryl phosphines, which occurs readily under ambient conditions. A rate constant as high as 18 m −1 s−1 was obtained between methyl 4‐azido‐2,3,5,6‐tetrafluorobenzoate and methyl 2‐(diphenylphosphanyl)benzoate in CD3CN/D2O. Furthermore, the iminophosphorane product was stable toward hydrolysis and aza‐phosphonium ylide reactions. This PFAA Staudinger reaction proved to be an excellent bioothorgonal reaction. PFAA‐derivatized mannosamine and galactosamine were successfully transformed into cell‐surface glycans and efficiently labeled with phosphine‐derivatized fluorophore‐conjugated bovine serum albumin. 相似文献
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《中国科学:化学(英文版)》2017,(5)
Functional nucleic acids(FNAs)-based biosensors have shown great potential in heavy metal ions detection due to their low-cost and easy to operate merits. However, in most FNAs based fluorescence probes, the ingenious designs of double-labeled(fluorophore and quencher group) DNA sequence, not only bring the annoyance of organic synthesis, but also restrict its use as a robust biosensor in practical duties. In this paper, we design a simple AIEgens functional nucleic acids(AFNAs) probe which consists of only fluorogen but no quencher group. With the help of duplex-specific nuclease(DSN) enzyme based target recycling, high fluorescence signal and superior sensitivity towards Hg~(2+) are achieved. This robust assay allows for sensitive and selective detection of Hg~(2+) in real water samples and mapping of intracellular Hg~(2+), without double-labeling of oligonucleotide with a dye-quencher pair, nor the multiple assay steps. 相似文献
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A nanogold-quenched fluorescence duplex probe has been developed for lighting up homogenous hybridization assays. This novel
probe is constructed from two strands of different lengths, and labeled by nanogold and a fluorophore at the long-strand 5′-end
and the short-strand 3′-end, respectively. The two tags are in close contact, resulting in complete quenching of the probe
fluorescence. If perfectly complemented to the nanogold-labeled strand, a long target oligonucleotide would displace the short
fluorophore-labeled strand, and as a result, restore the fluorescence. By using nanogold in the probe, an extremely high quenching
efficiency (99.1%) and removal of free fluorophore-labeled strand is achieved. The signal-to-noise ratio and the detection
limit (50 pmol L−1) of homogenous assays are therefore improved significantly, in comparison with similar probes using organic acceptors. Moreover,
the probe has a great inhibition effect on hybridization to a mismatched oligonucleotide. This effect provides the assay with
a high specificity, and particularly the assay has great potential in applications for discriminating variations in sequences.
The assay sensitivity could be markedly enhanced by using fluorescent materials in the signal strand that are brighter and
not quenched by nucleobases. 相似文献