荧光探针技术在两亲分子有序组合体研究中的应用

荧光技术具有灵敏度高、可测量参数丰富、扰动小、无破坏性等优点,因而在两亲分子有序组合体的研究方面得到极为广泛的应用。本文介绍了国内外利用各种荧光探针技术测定两亲分子有序组合体的微极性、微粘度、动力学过程、聚集数等微观信息,并对具有表面活性剂结构的荧光探针做了简要介绍,最后对基于荧光探针技术的两亲分子有序组合体的研究进行了展望。     

稳态荧光猝灭法确定胶束聚集数的研究

选用芘作为荧光探针, 二苯酮作为猝灭剂, 以稳态荧光猝灭法测定了十二烷基硫酸钠、十二烷基磺酸钠和十六烷基三甲基演化铵的胶束聚集致, 并对其测定胶束聚集数方法的有效范围进行了讨论. 实验结果表明, 选择的探针-猝灭剂体系适用于稳态荧光猝灭法确定阴离子和阳离子表面活性剂的胶束浓度和聚集数.     

寡聚核苷酸中鸟苷对四甲基罗丹明的荧光猝灭

具有核苷特异性的荧光猝灭技术在生物领域具有广泛应用.为了更好地理解这一过程的机理及其影响因素,研究了核苷对四甲基罗丹明（TMR）染料的分子间猝灭和在同一条寡聚核苷酸链中的分子内猝灭.与以前的研究结果一致,脱氧单磷酸鸟苷（dGMP）可以有效地猝灭TMR,而其他单磷酸腺苷对其的猝灭可以忽略.由斯特恩-沃尔默图获得TMR和dGMP的双分子猝灭常数为Ks=52.3L/mol.将TMR标记在寡聚核苷酸末端,可以观测到其荧光通过光致电子传递有效地被鸟苷猝灭,我们利用荧光相关光谱的方法测定了这一过程的猝灭速率常数.此外,所得的数据还显示鸟苷附近的碱基会对分子内的猝灭过程产生显著的位阻效应.这些结果将有助于设计寡聚核苷酸荧光探针和理解G猝灭过程.     

聚集诱导发光应用研究进展

传统的荧光化合物在聚集态时,会导致荧光猝灭;而聚集诱导发光(AIE)化合物在溶液中单分子状态时呈现弱的荧光,但当形成聚集态时发出强的荧光,这是由于分子内旋转受阻(RIR)和聚集形态的改变所致.综述了2008年以来聚集诱导发光最新应用研究进展,如用以检测离子、气体、有机小分子、爆炸物、蛋白、酶等化学/生物传感器;向传统的聚集引起猝灭化合物引入AIE单元,制备高效固态发光器件等;通过压力、热、溶剂蒸汽等调控聚集态,构建可逆的刺激性多重响应材料;发展与生物体具有良好兼容性的聚集体杂化纳米颗粒(如荧光硅纳米颗粒、聚合物胶束、电解质等),以用于生物体内成像、结构解析及检测等.     

厚朴酚在乙醇中的荧光自猝灭及猝灭机理

系统研究了厚朴酚的荧光光谱和吸收光谱随浓度的变化, 揭示了厚朴酚具有较强的自猝灭特性. 其猝灭包括静态和动态机制: 随着浓度增加, 厚朴酚发生聚集; 同时, 单体和聚集体对荧光的猝灭表现为动态猝灭, 由单体、二聚体、三聚体造成的荧光猝灭速率常数kqm、k qd、k qt值远大于扩散控制的荧光猝灭速率常数. 说明除扩散控制的短程能量转移引起的猝灭外, 厚朴酚还存在长程能量转移导致的猝灭机制.     

芘荧光探针法研究C60-胶束水溶液体系的微环境性质

首次运用芘荧光探针法考察了Ｃ６０－胶束水溶液体系的微环境性质,发现Ｃ６０的介入可以改变非离子表面活性剂所形成胶束的结构而破坏胶束的有序情,从而使胶束的体积变大。Ｃ６０能显著猝灭芘单分子的荧光,而几乎不会破坏芘单体与其激基二聚体的平衡,表明Ｃ６０主要是同芘单分子之间发生ＣＴ作用。同时Ｃ６０对芘单分子荧光的猝灭在有机体系中主要呈现静态猝灭而在胶束体系中则主要呈现动态猝灭。     

能量转移技术及其在溶液分子的微区结构分析中的应用

能量转移现象,即所谓的荧光猝灭和敏化荧光现象。通过观测能量转移现象,可以得到很多信息,特别是可以应用于对溶液中分子的微区结构分析。这一实验技术,可以补偿X-     

罗丹明-B及其烷基衍生物在表面活性剂溶液中探针功能的研究

近十年来,人们除对高度有序的分子晶体进行持续的深入研究外,对另一类有组织的分子集合体的研究也得到了蓬勃发展,特别是利用各种荧光化合物作为探针来研究微组织集合体(micro-organized assembly)的各种特性,更引起人们的光趣。用作荧光探针的化合物有一系列不同的类型,分别适用于不同的研究目的。某些对环境极性、粘度变化非常敏感的分子内电荷转移化合物探针的研究报道较多,对另一类探针化合物,其分子单体与聚集体有不同荧光特征,环境改变能影响探针分子单体与聚集体形成的条件,因此就可通过体系发光特性的变化来推断体系环境的改变,但对这类探针化合物的研究报道不多。已知罗丹明类染料的单体分子与其聚集体的发光行为有较大差别,将亲水性罗丹明化合物联以脂肪长链使之成为具有两亲性质的探针化合物已引起人们的注意,并在某些方面如研究细胞融合过程等取得了成功的应用,然而这类化合物某些基本物化性质的研究尚不够充分。本工作是在这样的背景下对几种带不同脂肪链的罗丹明化合物用作探针时的发光行为进行了比较研究。     

聚集诱导发光分子在公共安全领域中的应用

对于公共安全中存在的安全隐患及时检测和预防有助于保护公民的身体健康和财产安全。荧光检测技术以其优异的选择性、高的灵敏度、快的响应速度引起了广泛的研究。聚集诱导发光(AIE)材料作为一种与聚集导致发光猝灭(ACQ)材料截然相反的新兴有机荧光材料,实现了发光分子在固态或是聚集态下的高荧光量子产率。而独特的AIE特性,使其不必担心由于分子聚集导致的荧光信号的降低或猝灭,同时由于分子聚集程度的增加引起荧光颜色和强度的变化,可以被用来实现对靶标物的定性和定量分析,为荧光分析检测提供了新的思路和方案。目前基于AIE的荧光检测方法及相关技术已经被广泛应用各个领域,其中在公共安全领域的研究表现突出,并取得较高的研究成果。本文分析总结了近几年来AIE分子在公共安全领域中的应用进展,包括爆炸性物质、指纹识别、毒品检测、食品安全等方面,并对目前存在的问题和应用前景进行了总结和展望。     

酪氨酸猝灭Eosin Y的荧光

氨基酸残基对探针分子的荧光猝灭行为可以为生物大分子的结构及构象动力学研究提供重要的信息.本文运用飞秒瞬态吸收光谱和时间相关单光子计数实验系统研究了在水(H₂O)和氘代水(D₂O)溶液中乙酰基取代酪氨酸(AcTyr)对Eosin Y的超快荧光猝灭动力学过程.发现导致AcTyr对Eosin Y荧光猝灭的主要原因是由于它们之间形成了短寿命的基态复合物.我们还发现Eosin Y与AcTyr形成的基态复合物的激发态寿命具有明显的动力学同位素效应,表明AcTyr对Eosin Y的荧光猝灭是通过质子耦合电子转移过程发生的.     

A flow cytometric assay technology based on quantum dots-encoded beads

A flow cytometric detecting technology based on quantum dots (QDs)-encoded beads has been described. Using this technology, several QDs-encoded beads with different code were identified effectively, and the target molecule (DNA sequence) in solution was also detected accurately by coupling to its complementary sequence probed on QDs-encoded beads through DNA hybridization assay. The resolution of this technology for encoded beads is resulted from two longer wavelength fluorescence identification signals (yellow and red fluorescent signals of QDs), and the third shorter wavelength fluorescence signal (green reporting signal of fluorescein isothiocyanate (FITC)) for the determination of reaction between probe and target. In experiment, because of QDs’ unique optical character, only one excitation light source was needed to excite the QDs and probe dye FITC synchronously comparing with other flow cytometric assay technology. The results show that this technology has present excellent repeatability and good accuracy. It will become a promising multiple assay platform in various application fields after further improvement.     

Performance of amidocoumarins as probes for monitoring of cationic photopolymerization of monomers by fluorescence probe technology

The performance of 7‐benzamido‐4‐methylcoumarin ( B ) and 7‐acetamido‐4‐methylcoumarin ( C ) as fluorescent probes for monitoring of progress of cationic photopolymerization of monomers by fluorescence probe technology has been evaluated in comparison with 7‐diethylamino‐4‐methylcoumarin ( A ). It has been found that the probes B and C do not cause such a delay of the polymerization start as the probe A does, but in the case of B and C , the cure monitoring using the fluorescence intensity ratio at two wavelengths as an indicator of the polymerization progress is not applicable. An alternative monitoring parameter has been applied successfully and a method for compensation of the effects of probe photolysis is proposed. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

香豆素类荧光探针对硫化氢检测的研究进展

硫化氢(H2S)是目前人们发现的第三类生物内源性“气体信使分子”。其及时检测对人类的健康有着非常大的意义。随着荧光探针技术的发展,有机小分子荧光探针受到广大学者的关注。其中,香豆素因其结构简单,荧光量子产率高以及易于功能化而备受青睐。本文根据探针的识别机理综述近三年来报道的香豆素类H2S荧光探针代表性研究成果,并对其进行了展望,为后续设计开发更具实用价值的H2S荧光探针提供一点有益的参考。     

荧光染料探针分子对变异细胞的识别

介绍了变异细胞的结构特征、细胞识别与荧光标记技术以及荧光染料探针分子标记细胞的方式。简述了荧光染料探针分子用于变异细胞组织的标记与识别的研究新进展。并针对目前荧光染料探针分子的应用现状,分析了未来的发展趋势,包括增强荧光染料探针分子与人体组织的相容性、靶向性,提高其灵敏度,降低毒性等的方法和途径。简述了固相合成分离技术用于探针分子的制备与纯化的优越性。     

Application of Single—labelled Probe—primer in PCR Amplification to the Detection of Hepatitis B Virus DNA

A new method based on the incorporation of a single-lablled probe-primer into polymerase chain reaction(PCR) for the detection of PCR-amplified DNA in a closed system is reported.The probeprimerc consists of a specific probe sequence on the 5‘‘‘‘‘‘‘‘-end and a primer sequence on the 3‘‘‘‘‘‘‘‘-end.A flurophore is located at the 5‘‘‘‘‘‘‘‘end.The primeR-quencher is an oligonucleotide,which is complementary to the probe sequence of probe-primer and labelled with a quencher at the 3‘‘‘‘‘‘‘‘-end.In the duplex formed by probe-primer and primer-quencher.the fluorophore and quencher are kept in close proximity to each other.Therefore the fluorescence is quenched.During PCR amplificatio,the specific probe sequence of probeprimer binds to its complement within the same strand of DNA,and is cleaved by Taq DNA polymerase,resulting in the restoration of fluorescence.This system has the same energy transfer mechanism as molecular beacons,and a good quenching effciency can be ensured.Following optimization of PCR conditions,this method was used to detect hepatitis b virus(HBV) dna in patient sera.This technology eliminates the risk of carry-over contamination,simplifies the amplification assay and opens up new possibilities for the real-time detection of the amplified DNA.     

CD20靶向Cy7-Rituximab分子探针的制备及在小鼠活体荧光成像中的应用

以B淋巴细胞表面CD20抗原靶向的单克隆抗体Rituximab为载体, 通过共价键偶联荧光基团菁染料Cy7, 获得了新型荧光分子探针Cy7-Rituximab. 利用全光谱紫外-可见分光光度仪、SDS-聚丙烯酰胺凝胶电泳和基质辅助激光解析电离飞行时间质谱等对该探针结构进行表征, 并通过激光共聚焦显微镜观察了其在弥漫大B细胞淋巴瘤(DLBCL)细胞中的摄取情况. 选用BALB/C裸鼠为模型, 尾静脉注射 Cy7-Rituximab, 通过活体荧光成像系统观察了其在小鼠体内的分布情况. 研究结果表明, 修饰后的Cy7-Rituximab保持了原有抗体的免疫活性. 活体荧光成像结果表明, 在CD20高表达的脾脏部位监测到该分子探针的特异性浓集.     

Fluorescence probes for investigation of epoxy systems and monitoring of crosslinking processes

The fluorescence behavior of 1,1′‐dimethyl‐2,2′‐carbocyanine and p‐N,N‐dimethylamino‐styryl‐2‐ethylpyridinium was investigated in several epoxy systems. Time‐correlated single photon counting was used for all fluorescence measurements to obtain the rate constant for viscosity or mobility‐dependent nonradiative processes of the probe. Microviscosity effects were discussed on the basis of a model describing the microfriction between matrix and probe molecules. The probes investigated are able to detect the glass‐transition temperature of the materials investigated. These compounds also show a dependence on the mobility in the glassy state. The probes applied in this work also can be used to monitor the crosslinking process of several epoxy systems containing 4,4′‐diaminodiphenylmethane (DDM) as curing agent. The epoxides used for the crosslinking process were 2,2′‐[(1‐methylethylidene)bis(4,1‐phenyleneoxymethylene)bis‐oxiranemethaneamine] [common name, diglycidyl ether of bisphenol A (DGEBA)], N‐oxiranylmethyl‐N‐phenyl‐oxiranylmethane [common name, diglycidyl aniline (DGA)], and epoxy novolacs of different functionality. The networks obtained have a different morphology, which was studied by the fluorescence probe technology. The structure of the epoxy compound has an important influence on the probe behavior because both network density and size of the free volume influence the photochemical behavior of the probe. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 1367–1386, 1999     

能量色散X射线荧光探针用于古陶瓷的工艺与产地研究

利用能量色散X射线荧光(EDXRF)探针技术,研究了旧县坪遗址出土的一件青瓷样品的制造工艺与产地。从青瓷样品的器壁部,用切割法取下一个断面,用探针进行线性扫描分析。结果表明:在胎釉间存在的白色层状物的化学成分介于胎釉之间,断定其应为在烧制过程中经一系列理化反应而形成的反应层。经对该青瓷样品胎釉化学成分的聚类分析,发现其与宋代河南临汝窑青瓷的胎釉化学成分基本一致。并且,该样品与临汝窑青瓷在釉色和装饰风格上都相近。因此,旧县坪遗址的这件青瓷样品应为临汝窑制品。     

Fiber-optic chlorine probe based on fluorescence decay of N-(6-methoxyquinolyl)acetoethyl ester

A fiber-optic probe for measuring chlorine in aqueous solution is evaluated. The probe uses a microporous gas-permeable membrane to trap a small volume of aqueous internal solution made of N-(6-methoxyquinolyl)acetoethyl ester (MQAE) in front of a fiber-optic assembly. The working principle of this probe is based on a combination of fluorescence quenching and redox reaction of MQAE by chloride ion and chlorine, respectively. While the magnitude of total fluorescence decay is independent of the sample concentration, the initial rate of decrease in fluorescence intensity is linearly proportional to the chlorine concentration over the range from 8.4 to 418 microM. Once the probe is exposed to a chlorine sample, the probe tip must be refilled with a fresh aliquot of the internal solution before the next measurement. In this mode, the probe displays excellent reproducibility; the relative standard deviation of the initial rate of fluorescence decay (n = 3) is only 1 percent. This probe can also be used for the measurement of hypochlorous acid (HOCl) in aqueous solution. The response properties are identical to those of the chlorine probe.     

特异性识别半胱氨酸荧光探针的合成及细胞成像研究

基于光诱导电子转移(PET)机制,利用Cys亲核性较强,能够与探针分子发生亲核取代反应,使丙烯酰基离去,使探针分子体系内PET过程失效,合成了一种特异性识别半胱氨酸的荧光探针。当向探针溶液分别加入多种测试物时,除与Cys结构类似的Hcy和GSH会引起探针溶液微弱的荧光变化外,其他氨基酸均不会引起探针溶液荧光强度的变化,该探针对Cys具有良好的选择性和灵敏度,可在生理条件下检测Cys,并且区分Hcy和GSH。同时,该探针成功实现了细胞内Cys的荧光成像,为在生物学及医学中的实际应用建立了一种特异性识别Cys的分析方法。