基于牛血清白蛋白荧光探针的盐酸特拉唑嗪含量测定

对牛血清白蛋白（BSA）与盐酸特拉唑嗪（THD）混合体系进行了荧光发射光谱和同步光谱实验研究。BSA溶液在340 nm处有明显荧光特征峰,当加入THD后导致牛血清白蛋白发生内源荧光猝灭。据此建立了以BSA为探针的THD含量测定方法,通过该方法所得的模型函数相关系数都高于0.99。对所得模型函数进 行了实验验证,其中发射光谱模型函数回收率为96.04%~103.16%,同步光谱模型函数回收率为100.41%~ 105.58%,相对标准偏差分别为3.70%和2.42%。荧光发射光谱和同步光谱方法的检出限分别为0.64×10^-8 mol/L和0.66×10^-8 mol/L,定量限分别为0.21×10^-7 mol/L和0.22×10^-7 mol/L。     

小分子荧光探针的光谱

运用紫外-可见光谱、荧光光谱法研究了以二烯酮为荧光团的1,5-双(4-羟基)-1,4-戊二烯-3-酮探针的光学性质.一系列pH滴定实验表明探针的紫外吸收和荧光光谱随溶液的pH值的改变而变化.同时,探针紫外吸收光谱发生明显的红移,荧光光谱强度也随之变化,在碱性条件下,相对荧光强度浮动较大.解离常数pK<,α>为9.25,...     

以铽离子为荧光探针测定尿样中痕量环丙氟哌酸

详细研究了环丙氟哌酸同稀土离子铽形成的配合物体系的荧光光谱特性及实验条件对荧光强度的影响。在pH为6．0的条件下,配合物荧光体系可发射铽离子强的特征荧光,其最大激发和发射波长为328和545nm。以稀土离子铽为荧光探针,测定尿样中痕量的环丙氟派酸可获得满意结果。     

Interaction of a New Fluorescent Probe with DNA and its Use in Determination of DNA

In this paper we reported a metal complex 1-Zn (2,5-di-[2-(3,5-bis(2-pyridylmethyl)amine-4-hydroxy-phenyl)-ethylene]-pyrazine-Zn) as a fluorescent probe sensing DNA. The result of the competitive experiment of the probe with ethidium bromide (EB) to bind DNA, absorption spectral change and polarization change in the presence and absence of DNA revealed that interaction between the probe and DNA was via intercalation. Ionic strength experiment showed the existence of electrostatic interaction as well. Scatchard plots also confirmed the combined binding modes. The fluorescence enhancement of the probe was ascribed to highly hydrophobic environment when it bound the macromolecules such as DNA, RNA or denatured DNA. The binding constant between the probe and DNA was estimated as 3.13 × 10⁷ mol⁻¹ L. The emission intensity increase was proportional to the concentration of DNA. Based on this, the probe was used to determine the concentration of calf thymus DNA (ct-DNA). The corresponding linear response ranged from 2.50 × 10⁻⁷ to 4.75 × 10⁻⁶ mol L⁻¹, and detection limit was 1.93 × 10⁻⁸ mol L⁻¹ for ct-DNA.     

以牛血清白蛋白为荧光探针的格列吡嗪含量测定方法

在pH=7.40的Tris-HCl缓冲溶液中,牛血清白蛋白(BSA)与格列吡嗪(Glipizide)的相互作用会使BSA荧光有规律地发生猝灭,据此建立了以BSA为探针的Glipizide含量测定方法。Glipizide浓度在0.25～20μmol/L范围内与荧光强度呈现良好的线性关系,方法的检出限为0.071μmol/L。对于片剂中Glipizide含量的测定,平行6次测定的相对标准偏差为1.29%～2.80%,回收率为86.79%～96.43%。     

荧光增强法测定噻菌灵新体系

建立一种测定噻菌灵的荧光分析新方法.铽(Ⅲ)为弱荧光物质,噻菌灵的加入对其荧光强度有显著的增强效应.实验结果表明,荧光增强值△F与噻菌灵的浓度在2-200nmol/L内呈良好的线性关系,r=0.9970,检出限为0.83nmol/L.本法用于实际样本中噻菌灵的测定,结果令人满意.     

Estimation of PAMAM Dendrimers' Binding Capacity by Fluorescent Probe ANS

Dendrimers are globular, hyperbranched polymers which possess a high concentration of surface functional groups and internal cavities. These unique features make them very useful to many biomedical applications, especially as carrier molecules. This study presents results of estimation of polyamidoamine (PAMAM) dendrimers and human serum albumin (HSA) binding capacity of fluorescent probe 1-anilinonaphthalene-8-sulfonic acid (ANS). It has been shown that fluorescent probes can be used for quantitative analysis of dendrimers' binding capacity.     

Two-Photon Fluorescence Lysosomal Bioimaging with a Micelle-Encapsulated Fluorescent Probe

We report two-photon fluorescence microscopy (2PFM) imaging and in vitro cell viability of a new, efficient, lysosome-selective system based on a two-photon absorbing (2PA) fluorescent probe (I) encapsulated in Pluronic® F-127 micelles. Preparation of dye I was accomplished via microwave-assisted synthesis, resulting in improved yields and reduced reaction times. Photophysical characterization revealed notable 2PA efficiency of this probe.     

结构匹配酞菁缔合物红区荧光探针在纳克级肝素测定中的应用

肝素是一种聚阴离子生物活性多糖,具有重要的临床价值,简便快速、特异性高的分析方法的研发一直受到重视。基于分子缔合作用原理,构建了酞菁离子缔合物荧光探针,并籍此建立了肝素高特异、高灵敏的荧光分析新方法,分析浓度可达纳克级。发射强红色荧光的四磺基铝酞菁（AlS₄Pc）是一种带负电的金属酞菁荧光化合物,研究发现,母体结构相同、荷电相反的阳离子铜酞菁化合物阿利新蓝（Alcian blue 8 GX）对AlS₄Pc具有高效荧光猝灭作用。由于二者均具有大平面的酞菁母体,但电性相反,分子结构有着高度的匹配性,易于通过静电作用、平面疏水作用等分子间力而形成强的缔合作用,生成近乎无荧光的缔合物。据此现象构建了AlS₄Pc-Alcian blue 8 GX缔合物荧光探针。进一步的糖类物质考察、筛选实验显示,具有强负电性的阴离子生物多糖可以使AlS₄Pc-Alcian blue 8 GX缔合体系的荧光发生不同程度的恢复,重新发出AlS₄Pc的荧光,其中尤以肝素存在下的荧光恢复行为最为显著,且恢复程度与肝素的浓度呈正相关。这是因为肝素带有大量磺酸根阴离子,对AlS₄Pc构成强的竞争结合（Alcian blue 8GX）的作用,导致AlS₄Pc从缔合体系中游离出来,体系荧光得以恢复。基于这一发现,研究建立了一种高灵敏、高特异性测定肝素的荧光增强分析法。考察了体系的分子光谱（荧光光谱和吸收光谱）行为以探讨缔合物形成和反应体系荧光恢复的作用机理;对反应参数（包括pH、反应温度、反应时间、AlS₄Pc以及Alcian blue 8 GX的用量等）进行了优化;在最佳条件下,方法的线性回归方程y=1.08x+58.62,工作曲线线性区间为6.0～600.0 ng·mL-1,检测限为5.7 ng·mL-1;提出了简便实用的样品前处理方法（极性有机溶剂沉淀分离法）以解决实际样品测定时存在偏差的问题;此外,较为全面地考察了多种类物质（常见阴、阳离子、小分子、表面活性剂及生物大分子）对肝素测定的干扰行为;本法应用于实际样品（肝素钠注射液）的测定,取得了较为满意的结果。开拓了酞菁类化合物作为分子光谱探针在分析科学中的应用。     

快速简便的杂交检测DNA

Southern杂交作为黄金标准,已广泛运用于DNA的检测上。但是,经典的southern杂交和近年来一些DNA检测方法存在放射性污染,操作繁琐,耗时,对实验仪器设备要求高等问题。本文利用异硫氰酸荧光素(FITC)标记的dUTP合成DNA探针建立了快速检测DNA的液相杂交方法。该方法包括探针制备、液相杂交、电泳分离和信号检测四个步骤,并在此基础上对FITC-双链和FITC-单链探针的杂交效果作了比较。结果显示,使用FITC标记的两种探针都能取得良好的实验结果,但单链探针较双链的检测灵敏度高;双链DNA探针可以检测出0.8 μg(3.64×10-13 mol)的质粒,而单链DNA探针可以检测出0.38 μg(1.82×10-13 mol)的质粒DNA,在检出效率上是前者的2.1倍。整个检测过程操作简便,可在3 h内完成,可较好地解决了其他DNA检测方法存在的费时费力的问题。     

荧光探针法研究有机溶剂对DNA行为构象的影响

以溴化乙锭为荧光探针,考察了醇类、丙酮、乙腈等部分常见有机溶剂对DNA构象变化的影响,通过对荧光光谱,Scatchard图,DNA热变性曲线,并结合紫外吸收光谱等研究表明,有机溶剂使DNA的构象由B型向A型转变,但DNA并不发生解旋或降解。本实验为进一步研究的有机溶剂条件下DNA与非水溶性抗癌药物的相互作用机理提供了前提条件,同时也将有助于对某些生命生理现象的理解。     

A Fluorescent Probe for Diacetyl Detection

A water-soluble fluorescent probe, rhodamine B hydrazide (RBH), was prepared and its properties for recognition of diacetyl were studied. The method employs the reaction of diacetyl with RBH, a colorless and non-fluorescent rhodamine B spiro form derivative to give a pink-colored fluorescent substance. In weakly acidic media, RBH reacts more selectively with diacetyl than with other carbonyls, causing a large increase in fluorescence intensity and thereby providing an easy assay for the determination of diacetyl.     

2,6-Dansyl Azide as a Fluorescent Probe for Hydrogen Sulfide

A second-generation sulfonyl azide-based fluorescent probe, 2,6-DNS-Az, has been developed for the quantitative detection of H₂S in aqueous media such as phosphate buffer and bovine serum. Compare to the first-generation 1,5-DNS-Az probe, this probe shows both high sensitivity in phosphate buffer without the need for addition of surfactant and selectivity for sulfide over other anions and biomolecules, and thus can be used as a useful tool for detection of H₂S in the biological system.     

一种可用于细胞内汞离子可视化检测的荧光探针

将硫代罗丹明6G酰肼(R6GS)应用于水溶液和活细胞内汞离子的荧光成像检测.在测试体系中,R6GS本身溶液无色,荧光非常弱;加入汞离子后,溶液立刻变为粉红色且荧光显著增强,而对其他离子则没有响应,表明该探针分子对汞离子有较高的选择性和较高的灵敏性.荧光光谱显示R6GS对0-1.0×10-5mol/L的汞离子有较好线性关系,检出限为6.25×10-7mol/L.最后,该探针被成功用于官颈癌细胞中Hg2+的荧光成像研究.     

Use of FITC as a Fluorescent Probe for Intracellular pH Measurement

Fluorescein Isothiocyanate (FITC) is widely used in biology and medicine as a fluorescent marker for labeling various proteins. Particularly fluorescence marking of antibodies could not be imagined without FITC. However, at the same time FITC displays pH-indicative properties. This paper evaluates the limits of the use of FITC as a pH indicator in biological material, namely, for intracellular and intraorganellar pH measurement.     

Detecting H_2S Gas Concentration by 1,8-Naphthalimides Fluorescent Probe

针对传统硫化氢检测方法灵敏度低的问题,以1,8-萘酰亚胺为荧光基团,基于H₂S的还原性,通过在荧光分子结构上引入具有氧化性的硝基,合成一种可与硫化氢气体发生氧化还原反应生成有荧光响应的小分子荧光探针。该探针本身荧光十分微弱,且荧光峰值在λ=467 nm和λ=522 nm处。与H₂S反应之后,522 nm处的荧光效应消失,467 nm处的荧光效应显著增强。测定小分子荧光探针在通入H₂S气体前后的荧光光谱,分析467 nm处的荧光强度与气体浓度关系。结果表明：荧光光谱法检测出的H₂S气体浓度与荧光强度之间存在很强的线性关系,相关系数为0.979 3,最低可检测极限可达0.88×10-6 mol·L-1量级。表明基于1,8-萘酰亚胺衍生物的荧光光谱检测法可为油气田H₂S气体浓度的的快速测定提供参考。     

荧光探针法研究百草枯与DNA的相互作用

以中性红（NR）为分子探针,应用紫外光谱法和荧光光谱法研究了除草剂百草枯（PQ）与小牛胸腺DNA（ctDNA）之间的相互作用。在pH7.3的Tris-HCl（5×10-2mol.L-1）缓冲溶液中,NR分子主要以嵌插方式结合到ctDNA双螺旋结构上,百草枯的加入抑制了NR与ctDNA之间的结合,用Stern-Volmer方程进行数据处理,表明百草枯对ctDNA-NR的荧光猝灭不是单纯的静态或动态猝灭方式,属于混合型的。综合紫外光谱、离子强度等研究证实,在该实验条件下,百草枯与DNA之间存在静电和嵌插两种作用。     

稀土配合物分子印迹荧光探针的制备及检测孔雀石绿的残留

孔雀石绿是一种人工合成的三苯甲烷类化合物.孔雀石绿的常规检测方法前期处理复杂、耗时长、需要使用大型仪器等缺点导致不能及时的对其进行检测.所以研究出一种能够高效、便捷、快速的检测孔雀石绿残留的方法具有十分重要的意义.分子印迹聚合物(M IPs)是一种多孔隙材料,具有特定的识别位点,可以对特定的目标分子进行识别和吸附.稀土...     

Bioimaging of Peroxynitrite in MCF-7 Cells by a New Fluorescent Probe Rhodamine B Phenyl Hydrazide

Peroxynitrite is a potent oxidizing and nitrating agent which has detrimental effects on cells by altering the structure and function of biomolecules present within. A fluorescent probe rhodamine B phenyl hydrazide (RBPH) has been proposed for peroxynitrite (ONOO^?) imaging in MCF-7 cells based on its oxidation property, which converts RBPH to pink colored and highly fluorescent rhodamine B. The fluorescence emission intensity of the rhodamine B produced in the above process is linearly related to the concentration of peroxynitrite. The method obeys Beer’s law in the concentration range 2–20 nM and the detection limit has been found to be 1.4 nM. The possible reaction mechanism of peroxynitrite with RBPH to produce rhodamine B has been discussed with spectroscopic evidence. The Probe is selective to the peroxynitrite in the pH range 6–8 which is near physiological pH. Fluorescence microscopic studies suggest that the probe is cell permeable and hence peroxynitrite was imaged in MCF-7 cells.