新型4-羟基香豆素衍生物的微波合成及其光谱性质

以4-羟基香豆素(a)为原料微波辐射合成了具有独特的生理活性和荧光性能的3,3′,3″,3′″-亚乙四基-4-羟基香豆素(b)、3,3′-苯亚甲基-双-4-羟基香豆素(c)和4-羟基香豆素-1,4-萘醌(d)系列4-羟基香豆素衍生物, 采用元素分析、红外光谱、核磁共振及质谱表征了产物的结构, 并对其紫外-可见吸收光谱及荧光光谱性质进行了研究, 探索了化合物的微观结构与其光学性能之间的关系. 研究结果表明, 具有“近平面”、大π共轭和对称型结构的化合物b具有较大的摩尔吸光系数及强荧光特性, 且浓度在0.50~1.50×10^-4 mol/L范围时, 其荧光强度随着浓度的降低而呈线性增加; 在pH=1.81~6.09时, 荧光强度随pH降低而减弱, 在pH 8.36~11.98时, 荧光强度随pH升高而减弱. 此外, 牛血清白蛋白(BSA)及脱氧核糖核酸(DNA)可与该化合物发生相互作用, 进而敏化增强该分子的内源荧光.     

4个天然1,7-二芳基庚烷类化合物的合成

合成了4个天然1,7-二芳基庚烷类化合物:1-(4′-羟基-3′-甲氧基苯基)-7-(4″-羟基苯基)-5-羟基-3-庚酮(1),1-(4′-羟基-3′-甲氧基苯基)-7-(4″-羟基苯基)-4-庚烯-3-酮(2),1-(3′,4′-二羟基苯基)-7-(4″-羟基苯基)-5-羟基-3-庚酮(3),1-(3′,4′-二羟基苯基)-7-(4″-羟基苯基)-4-庚烯-3-酮(4).化合物1,2,4为首次合成.     

基于四联苯臂星型小分子凝胶剂的TNT薄膜荧光传感器

基于具有三苯胺中心核、咔唑外围和四联苯连接臂的星型荧光小分子三(4″″-(3, 6-二叔丁基-咔唑-9氢-9-基)-(1, 1': 4', 1″':4″', 1?:4?, 1″″-四苯基)-4-基)胺(N5), 采用溶液旋涂的方法制备了用于检测三硝基甲苯(TNT)饱和蒸汽的高效荧光传感薄膜。 不同于具有单苯连接臂的模型化合物三(4'-(3, 6-二叔丁基-咔唑-9氢-9-基)-(1, 1'-二苯基)-4-基)胺(N2), N5由于长共轭臂的存在, 容易在苯类溶剂中通过π-π相互作用组装形成凝胶。 同时, 其旋涂薄膜具有细小纳米级纤维状的组装形貌, 表面出现一定的多孔结构, 有利于气体分子的渗透。 因此, 应用于TNT蒸汽的检测, 化合物N5薄膜表现出比N2薄膜更快的荧光淬灭响应速度和更高的淬灭效率。 特别是TNT传感特性几乎不受化合物N5膜厚的影响, 当膜厚为94 nm时, 在1和30 min的淬灭程度仍然可以达到44%和90%。     

两种氧氮杂环戊二烯类化合物的紫外和荧光光谱的溶剂效应

前文报道了1,4-二(5-苯基-1,3,4-嚼二唑基-2)苯(PDPDP)紫外、荧光光谱的溶剂效应.为了与PDPDP比较,又合成了1-(5-苯基-1,3,4-噁二唑基-2)-4-(5′-苯基-1′,3′-噁唑基-2′)苯(PDPOP)和1-(5-苯基-1,3,4-噁二唑基-2)-4-(2′-苯基-1′,3′噁唑基-5′)苯(PDPO′P).     

4,4′-双(4″,4″,4″-三氟代-1″,3″-二氧代丁基)联苯铕配合物的合成及发光性能

合成了2个新的配合物Eu2(btb)3(H2O)4(1)和Eu2(btb)3(phen)2(2)[H2btb=4,4′-双(4″,4″,4″, -三氟代 - 1″,3″-二氧代丁基)联苯, phen=1,10-邻菲罗啉]. 采用元素分析、红外光谱、紫外光谱和快原子轰击质谱表征了2个配合物的结构. 在近紫外光激发下, 配合物1和2都发射出强的铕离子特征红光. 对614 nm 红光进行监控, 其激发光谱在395 nm处具有最大的激发强度, 与InGaN芯片发射的近紫外光激发相匹配. 将配合物1和2与395 nm 发射的InGaN芯片进行组合制备了红色发光二极管. 在配合物和硅树脂的质量比为1∶25的情况下, 2个红色发光二极管的色坐标分别为x1=0.5210, y1=0.2285(配合物1); x2=0.5835和y2=0.2857(配合物 2), 位于标准的国际色坐标红色区域; 器件的发光效率分别为0.65和0.76 lm/W. 研究结果表明, 配合物1和2是制作白光二极管可供选用的红色发光材料.     

一维链状配位聚合物[Zn(tpa)(tripy)]n·nH2O的合成与结构表征

采用水热法合成了新的一维链状锌的配位聚合物[Zn(tpa)(tripy)]_n·nH₂O(tpa=对苯二甲酸,tripy=4′-(4-甲氧基苯基)-2,2′∶6′,2″-三联吡啶),通过红外光谱和元素分析对该配位聚合物进行了结构表征,用Ｘ射线单晶衍射测定了晶体结构。 结果表明,该配位聚合物属单斜晶系,P21/c空间群,a＝0.855 0(2) nm,b＝2.825 0(6) nm,c＝1.096 0(2) nm,β＝107.14(3)°,V＝2.529 7(9) nm³,Z＝4,D_c＝1.541 g/cm³,M_r＝586.88,F(000)＝1 208。 最终偏离因子R₁＝0.100 6,ωR₂＝0.264 8。 该化合物中Zn原子和2个对苯二甲酸酸根中的2个O原子和1个三联吡啶中的3个N原子配位。 相对于配体,该配位聚合物表现出明显增强的荧光发射性质。     

杯[4]芳烃的表面化学组装及其在气态四氢呋喃荧光传感薄膜创制中的应用

挥发性有机化合物(Volatile Organic Compounds,VOCs)是重要的大气污染物,严重地危害着人类健康.本文设计合成了一种末端携带反应活性硅氧烷基团的杯[4]芳烃衍生物,通过自组装和表面化学反应将其共价结合于玻璃基质表面,获得了一种杯[4]芳烃修饰玻璃基质.以此基质物理担载荧光活性物质--芘封端三聚噻吩(Py-3T),得到了一种对气相四氢呋喃具有"turn-on"及快速灵敏(26.7 μg/mL)响应特性的荧光传感薄膜.实验表明:除苯和甲苯之外,其它常见有机溶剂和化学物质蒸汽对该薄膜荧光发射基本没有影响.苯和甲苯也因响应程度小、响应速度慢而难以干扰测定过程.据此,可以预期该荧光薄膜有可能在THF气体传感上获得应用.     

多色发光层状稀土氢氧化物/聚甲基丙烯酸甲酯复合荧光薄膜的组装

本文通过水热法合成了含有3种不同稀土离子的层状稀土氢氧化物(Gd0.5Tb0.5-xEux)2(OH)5NO3.nH2O,并选择有机物水杨酸(HSA)作为敏化剂,通过在水热条件下的离子交换反应,成功将其以有机阴离子形式与层状稀土氢氧化物插层组装获得有机-无机杂化荧光材料(SA--LRHs∶xEu)。荧光性质测定表明,SA-通过有效的能量转移增强了Tb3+的特征绿色荧光发射,随着Eu3+含量的增加,Eu3+的特征红色荧光发射随之增强,而Tb3+的特征绿色荧光发射随之减弱。在此基础上,将发光颜色可调的有机-无机荧光材料与聚甲基丙烯酸甲酯(PMMA)复合组装出透明的荧光薄膜。     

2,2'-二苯并噁唑衍生物的合成和光性能研究

合成了16种2,2-二苯并(口恶)唑衍生物,测定了化合物的熔点、红外光谱、紫外吸收光谱、荧光发射光谱以及荧光量子产率,与1,4-二(苯并(口恶)唑1′,3′-基-2′)苯和1,4-二(苯并(口恶)唑-1′,3′-基-2′)乙烯衍生物进行了比较,讨论了它们之间光谱特性的差异.     

新荧光试剂双(2-苯并噻唑重氮氨基)-3,3′,5,5′-四甲基联苯的合成及其分析应用

将3,3′,5,5′-四甲基联苯胺和苯并噻唑类试剂结合, 并引入杂环三氮烯结构, 合成了新荧光试剂双(2-苯并噻唑重氮氨基) 3,3′,5,5′-四甲基联苯(BBTDTMB), 其结构经红外光谱、 核磁共振谱和元素分析证实. 研究结果表明, 在碱性介质中, 该试剂在λex/λem=342 nm/420 nm处产生强荧光, 并且Ag(Ⅰ)对其荧光有很好的猝灭作用, 因而建立了BBTDTMB测定Ag(Ⅰ) 的新荧光分析方法. 该方法的线性范围为1.0～240 μg/L, 检测限为 0.5 μg/L, 应用于人发、 茶叶中的Ag(Ⅰ) 的测定, 结果令人满意.     

Fluorescence-based Artemisinin Sensing Using a Pyronin B-doped Cellulose Film Reconstituted from Ionic Liquid

In this work, the first use of a cellulose hydrogel film reconstituted from ionic liquid (IL) 1-butyl-3-methylimidazolium chloride for the fluorescent determination of a plant antimalarial endoperoxide artemisinin is reported. The sensing material was fabricated by noncovalent co-immobilization of the fluorescent cationic dye pyronin B and complex of Mn(II) with anionic surfactant sodium dodecyl sulfate into the film prepared by dissolution and regeneration of microcrystalline cellulose in ionic liquid. Artemisinin determination in a concentration range of 0.25–8?µM is based on the dynamic quenching of pyronin B fluorescence (emission wavelength/excitation wavelength of 581/355?nm) that is accelerated by the above-indicated complex. The developed disposable cellulose film exhibits a high sensitivity toward artemisinin (limit of detection of 30?nM), sufficient selectivity for pharmaceutical analysis, a rapid response time (30?s), and a strong stable fluorescent signal for over a month. The applicability of the cellulose film was demonstrated by analyzing a dietary supplement with an extract from the traditional Chinese herb Artemisia annua. The accuracy of the fluorescent determination of artemisinin in the dietary supplement was supported by a liquid chromatography–mass spectrometry technique. The developed fluorescent cellulose film is a biocompatible and easy to handle sensing material that makes it suitable for wide variety applications in pharmaceutical analysis.     

三联噻吩衍生物功能化SiO2反蛋白石光子晶体荧光薄膜的制备及应用

将单分散聚苯乙烯微球乳液与SiO₂溶胶均匀混合后, 于恒温恒湿条件下, 竖直沉积共组装制备得到蛋白石型光子晶体薄膜, 然后利用牺牲模板法制得SiO₂反蛋白石光子晶体薄膜. 该薄膜依次经过浓硫酸与过氧化氢混合液、 3-氨丙基三甲氧基硅烷的甲苯溶液、 三联噻吩的三氯甲烷溶液和硼氢化钠的甲醇溶液处理后, 得到三联噻吩衍生物功能化的SiO₂反蛋白石光子晶体. 结果表明, 制备得到的光子晶体薄膜在512 nm处有荧光发射, 经紫外辐射后荧光猝灭, 甲醛气氛下458 nm处又出现新的荧光发射峰. 在甲醛气氛下20 s即可观察到荧光发射, 空气氛围下可恢复, 10次循环仍可保持强的荧光发射, 可重复性良好. 以无反蛋白石光子晶体结构的三联噻吩衍生物的平滑膜与甲醛作用的体系作为参比, 以330和400 nm聚苯乙烯微球为模板制备的三联噻吩功能化反蛋白石光子晶体, 在甲醛气氛中发射的荧光分别增强47.5和78.6倍. 这是由于光子晶体光子禁带的红带边和蓝带边与荧光发射波长相重叠, 产生了慢光子效应, 极大地增强了发射的荧光强度.     

Fluorescence emission from PAMAM and PPI dendrimers

A strong fluorescence emission from poly(amido amine) (PAMAM) dendrimers with different terminal groups or a poly(propylene imine) (PPI) dendrimer was studied under different conditions by varying experimental parameters such as pH value, aging time, temperature, and concentration. The increase of fluorescence intensity was fast at low pH or high temperature but linear with respect to dendrimer concentration. It was reasonable that the formation of a fluorescence-emitting moiety had a close relation to protonated tertiary amine groups in PAMAM or PPI dendrimers. Furthermore, oxidation of the tertiary amines was confirmed to play an important role, which was evidently caused by oxygen in air. The results of fluorescence decay indicated that the deactivation of luminescence was raised with increasing temperature. Dendrimers emitted blue photoluminescence along fiber chain templates on a fluorescent microscope.     

A fluorescent dosimeter for formaldehyde determination using the Nash reagent in silica gel beads

Based on the Nash reagent embedded in silica gel beads as a recognition element, a fluorescent dosimeter for formaldehyde determination is established. The system can act as a fluorescent off–on switch for the qualitative detection of formaldehyde. The fluorescence emission of the Nash reagent-loaded silica gel beads is “switches off” (or very low) before exposure to formaldehyde, while fluorescence can be switched on when the beads are contacted with formaldehyde. The slope of fluorescence time scan spectra changes with formaldehyde concentration, which constitutes the basis of quantitative determination of formaldehyde concentration. The formaldehyde can also be semi-quantitatively measured in a naked-eye-detectable fashion. No response of this dosimeter to primary alcohols, ketones and other common substances was observed. The dosimeter is sensitive, inexpensive, a disposable, and simple in operation.     

基于ZnS纳米粒子的有机凝胶荧光薄膜的制备及其传感性能

本文首先采用油水界面法制备发光纳米ZnS粒子,再通过物理混合法,将其分散在溶有小分子胶凝剂的有机溶液中,流延于玻璃基质表面,得到ZnS荧光薄膜。实验结果表明,ZnS纳米粒子的平均粒径大小约为200 nm,具有立方晶型结构,并且在杂化薄膜中具有良好的分散性;胶凝剂形成的网络结构对ZnS纳米粒子具有良好的限域效应,表现为稳定的发光性能;气敏实验表明,该杂化膜对挥发性有机单胺和二胺具有灵敏的选择性传感作用;且其灵敏度随着杂化薄膜中ZnS担载量的增大逐渐提高;可逆性实验表明该薄膜对乙二胺蒸汽具有良好的可逆响应性。     

Tuning Fluorescent Response of Nanoscale Film With Polymer Grafting

An effective method for tuning fluorescent response of an ultrathin (5 nm) polymer film, which can be used for generation of sensing arrays, is reported. This method is distinctive in that the modification of the optical response is achieved with polymer grafting of a non‐fluorescent polymer to a fluorescent film. Using this approach, a number of films demonstrating different fluorescent emission when exposed to solvent vapors were synthesized.     

Julolidine-labelled fluorinated block copolymers for the development of two-layer films with highly sensitive vapochromic response

Fluorinated block copolymers composed of a polystyrene (S_x) first block and a polyacrylate second block carrying hydrophobic/lipophobic perfluorohexyl side chains (AF) were prepared by atom transfer radical polymerization (ATRP). Fluorescence emission properties were imparted to the copolymers by incorporation in the second block of a julolidine-based fluorescent molecular rotor (JCBF). The synthesized block copolymers were used as the fluorescent low-surface energy thin top-layer onto a polystyrene bottom-layer to produce novel two-layer film vapochromic sensors. Contact angle and X-ray photoelectron spectroscopy (XPS) measurements revealed that the two-layer film surfaces were hydrophobic and lipophobic at the same time and highly enriched in fluorine content as a result of the effective segregation of the perfluorinated tails to the polymer-air interface. The fluorescence intensity of the two-layer films decreased significantly when they were exposed to vapours of organic solvents, including tetrahydrofurane, chloroform, and trifluorotoluene. However, an AF content-dependent sensing behaviour was also observed, with the two-layer films containing the copolymer with the shorter fluorinated block giving a more rapid and almost quantitative decrease in fluorescence variation. Fluorescence emission of the films was also proved to vary with temperature. Both the vapochromic and thermochromic responses were reversible after successive solicitation cycles. The fluorescence variation of the two-layer films was much more marked than that of the corresponding PS/JCBF blend, thus providing a system potentially applicable as highly sensitive volatile organic compound (VOC) sensor, thanks to the active role of the fluorinated block in promoting the migration of the fluorophore to the outermost surface layers.     

5,5-二乙烯基-2,2-联吡啶:可能的新型锌离子荧光探针(英文)

生物体系里微量元素锌在发育、新陈代谢和疾病的发生等多个领域扮演了重要的角色,定性和定量测量锌的含量将帮助我们理解锌的生物学意义。我们偶然发现5,5-二乙烯基-2,2-联吡啶(DVBP)在二氧六环里对锌离子呈现出类似比例计量型荧光探针的特性:即有2个荧光发射峰而且长波长峰随锌离子的增加按比例增长。但DVBP难溶于水而且2个荧光发射峰距离太近从而相互干扰,我们尝试利用硅氢反应将DVBP固定在多孔硅上制备感应锌离子的光极,我们发现多孔硅固相载体上的联吡啶通过与锌离子的螯合后荧光增强约8倍,比DVBP在溶液里与锌离子螯合后的荧光增强(约4.5倍)还要多,联吡啶对锌离子的荧光响应是一个值得继续探索的领域。     

六苯基硅烷-聚乙烯醇荧光复合薄膜的制备及传感性能

以聚乙烯醇(PVA) 高分子凝胶薄膜为基质, 将有机小分子发光染料六苯基硅烷(HPS) 纳米粒子掺杂到PVA薄膜内, 利用HPS的聚集诱导发射效应和凝胶薄膜的基质效应制备得到一种新型荧光薄膜. 扫描电子显微镜观察发现该薄膜具有典型的三维网络结构; 静态荧光光谱监测表明, 薄膜荧光性能稳定, 且荧光发射来自于无定形态和结晶态的HPS纳米粒子, 其中无定形态发射居多; 传感实验表明, 该薄膜对芳香族化合物气体表现出了灵敏的传感性, 灵敏度和猝灭效率取决于有机溶剂的挥发速度和薄膜的表面结构; 结合荧光寿命测定结果和HPS纳米粒子的发光机理, 推测芳香族化合物对薄膜荧光的猝灭源自其对HPS聚集体的解聚集作用; 实验还表明, 该薄膜对此类气体的传感呈现出良好的可逆性.     

Ratiometric fluorescent detection of acidic pH in lysosome with carbon nanodots

It is significant for cell physiology to keep the homeostasis of p H, and it is highly demanded to develop ratiometric fluorescent sensors toward p H. In this work, under mild condition, through the electrostatic interaction between carbon nanodots(CDs) and organic molecules, two novel ratiometric fluorescence hybrid nanosensors were fabricated for sensing acidic p H. These nanohybrid systems possess dual emission peaks at 455 and 527 nm under a single excitation wavelength of 380 nm in acidic p H condition.With the increasing of p H, the fluorescence of the 1,8-naphthalimide derivative completely quenches,while the blue fluorescence of CDs keeps constant. Furthermore, the CDsàorganic molecular nanohybrids exhibit excellent anti-disturbance ability, reversible p H sensing ability, and a linear response range in wide p H range respectively. Besides the ability to target lysosome, with one of the nanosensor, stimulated p H change has been successfully tracked in a ratiometric manner via fluorescence imaging.