Te掺杂n型GaAs材料的光致发光研究

对Ｔｅ掺杂ｎ型ＧａＡｓ材料在３００～６０Ｋ之间的辐射复合进行光致发光（ＰＬ）研究。用发射波长为５１０．６ｎｍ和５７８．２ｎｍ的溴化亚铜激光器为激发光源。在所选取的狭缝宽度下谱仪的分辨率约为２ｎｍ。所提供的数据全部经过系统灵敏度校正并进行分峰拟合。对ＰＬ谱中一些主要特征进行讨论，认为Ｔ１，Ｔ２，Ｔ３三个发射带分别对应着导带价带（Ｔ１）和施主受主（Ｔ２，Ｔ３）的跃迁，它们随温度变化的情况与带隙宽度及电子填充状态随温度变化有关。此外，还注意到ＰＬ谱的长波端（～９５０ｎｍ）呈上扬趋势，表明可能在低能区域存在一个与深能级复合有关的宽发射带     

长白山白眉蝮蛇蛇毒精氨酸酯酶1的研究Ⅱ.酶学性质和荧光光谱研究(续I)

测得了长白山白眉蝮蛇毒精氨酸酯酶１的最适反应的ＰＨ范围为７．０－８．０,且与酶反应底物对甲苯磺酰－Ｌ－精氨酸甲酯的反应无明显的最适应反应温度,荧光光谱的研究结果表明：该酶的酪氨酸残基的荧光被色氨酸残基的荧光所掩盖;同步荧光光谱结果表明：当发射波长与激素波长差△λ分别为２０ｎｍ和７５ｎｍ时,精氨酸酯酶１的荧光光谱分别由酪氨酸和色氨酸残基所贡献,且处于亲水性环境中;精氨酸酯酶１的荧光发射强度受溶液酸度     

铁（Ⅲ）—过氧化氢—水杨基荧光酮—溴化十六烷基三甲铵荧光猝灭反应？…

在ｐＨ３．１～５．２的ＨＣｌ－ＮａＡｃ缓冲介质中,溶液中的铁（Ⅲ）与过氧化氢（Ｈ２Ｏ２）,水杨基荧光酮（ＳＡＦ）和溴化十六烷基三发（ＣＴＭＡＢ）反应产生一多元混合络合物,使水杨基荧光酮溶液的荧光明显猝灭,据此建立了测定痕量铁的荧光猝灭分析法,该体系的激发波长λｅｘ＝４３５．８ｎｍ,发射波长λｅｍ＝５４０ｎｍ。铁的浓度在２～１００ｕｇ／Ｌ范围内有良好的线性关系;方法的检出限为０．４１ｕｇ／Ｌ。该方法     

桑色素荧光光度法测定二氯化双(丁氧羰乙基)锡

在ｐＨ３．０的ＨＡｃ－ＮａＡｃ缓冲溶液中和有Ｔｒｉｔｏｎ Ｘ－１００存在下,二氯化双（丁氧羰乙基）锡（简写为Ｒ２ＳｎＣｌ２）与桑色素形成１：１的荧光络合物。络合物的激发波长和发射波长分别为４４３．２ｎｍ和５１４。４ｎｍ。Ｒ２ＳｎＣｌ２中的Ｓｎ浓度在０￣３．０ｍｇ／Ｌ范围内,与络合物荧光强度呈线性关系。方法检出限为７．８１μｇ／Ｌ Ｓｎ,用于ＰＶＣ中间产品和污水中Ｒ２ＳｎＣｌ２的测定,结果满意,相对     

Ru（bipy）2（PIP）（Ⅱ）与DNA相互作用的荧光光谱研究及其分析应用

利用ＤＮＡ对Ｒｕ（ｂｉｐｙ）２（ＰＩＰ）（Ⅱ）的荧光增强作用建立了测定ＤＮＡ的新方法。激发,发射波长分别为４６９ｎｍ和５９０ｎｍ。当Ｒｕ（ｂｉｐｙ）２ＰＩＰ（Ⅱ）的浓度为１．０μｇ／ｍＬ时,体系的荧光强度达到最大。     

钙黄绿素蓝荧光法测定食品中的微量锌（Ⅱ）

本文研究了在ＣＴＭＡＢ存在下，用钙黄绿素蓝荧光法测定食品中的微量锌（Ⅱ）的实验条件。在本实验条件下，Ｚｎ（Ⅱ）与钙黄绿素蓝生成１：１的配合物使钙黄绿素蓝的荧光增强，最大激发波长和最大发射波长分别为３５３ｎｍ和４４０ｎｍ。     

槲皮素-锡(Ⅳ) 荧光光度法的研究及其应用

研究了槲皮素－锡（Ⅳ）荧光体系的形成条件,建立了测定了槲皮素的荧光度法。在０．００８ｍｏｌ／ＬＨＣｌ介质中,形成ｎ（槲皮素）：ｎ「锡（Ⅳ）」＝２：１的荧光络合物。ＴｒｉｔｏｎＸ－１００对体系有强烈的增敏作用,激发波长为４４３ｎｍ。发射波长为４９５ｎｍ。     

锆—氟—7—碘—8—羟基喹—5—磺酸—EDTA—表面活性剂体系的荧光光度研究

在ＰＨ５．５－７．０的ＨＡｃ－ＮａＡｃ缓冲溶液中，锆与氟、７－碘－８－羟基喹啉－５磺酸、ＥＤＴＡ及十六烷基溴化铵形成五元荧光络合物，其组成为Ｚｒ（Ⅳ）：Ｆ：Ｈ２ＱＳＩ：ＥＤＴＡ：ＣＴＭＡＢ＝１：２：１：１：４。络合物的最大激发波长（λｅｘ）为３６５ｎｍ，最大发射波长为５００ｎｍ。     

3,5—二溴—4—氨基苯基荧光酮荧光熄灭法测定纯铅中微量铟的研究

详细研究了在阳离子表面活性ＣＴＭＡＢ存在下，３，５－二溴－４－氨基苯基荧光酮（ＤＢＡＰＦ）与铟形成络合物荧光熄灭法测定微量铟的实验条件。在ｐＨ６．２的ＨＡｃ－ＮａＡｃ缓冲溶液中，当激发波长λｅｘ＝５２３ｎｍ，荧光发射波长λｅｘ＝５５２ｎｍ时，铟含量在０￣３００μｇ／Ｌ范围内与体系的荧光熄灭程度成线性关系；检测限为１．７×１０＾－５ｇ／ｌ，试验了十多种离子干扰情况，选择性较好；已用于分析纯铅中微量铟     

5′—硝基水杨基荧光酮荧光熄灭法测定微量钨

本文基于Ｗ（Ⅵ）－５′－硝基水杨基荧光酮（５′－Ｎ－ＳＡＦ）－Ｔｗｅｅｎ－８０体系的荧光熄来效应，提出一种测定微量钨的荧光方法，在０．２～１．０ｍｏｌ／Ｌ的硫酸介质中，在Ｔｗｅｅｎ－８０存在下，５′－Ｎ－ＳＡＦ存在两个激发峰，其激发波分别为λｅｘ１＝４７５ｎｍ，λｅｘ２＝５０５ｎｍ发射波长为λｅｍ＝５２５ｎｍ。Ｗ（Ⅵ）与５′－Ｎ－ＳＡＦ形成１：３的配合物，钨浓度在每２５ｍＬ０．２５～２．５μｇ范围     

两种不同光谱类型的R-藻红蛋白的荧光性质研究

红藻中的R-藻红蛋白(R-PE)依照其吸收光谱可分为两种不同的光谱类型,即“双峰型”和“三峰型”。本文通过对不同pH条件下的R-PE的荧光光谱及荧光寿命的研究,发现“三峰型”R-PE的pH稳定范围较“双峰型”R-PE大。在R-PE浓度对荧光光谱的影响实验中,随着蛋白浓度的增加,荧光峰位置逐渐红移。荧光寿命逐渐增大,荧光强度先行增加而后减弱。用碘离子对其荧光进行猝灭,随着碘离子浓度的增大,荧光强度逐渐降低,荧光寿命逐渐缩短,并服从Stem-Volmer规则。     

Laser-induced Fluorescence Spectroscopy of NiO between 510 and 650 nm

Laser-induced fluorescence excitation spectra of NiO have been recorded in the wavelength region of 510-650 nm under supersonic molecular beam conditions. More than fifty bands have been observed and rotationally analyzed to determine the molecular constants. The excited states exhibit highly irregular variations in terms of isotopic shifts, vibrational intervals, and rotational constants. Twenty-six bands attributed to [Ω=0, 1]-X3∑o transitions have been tentatively grouped into five vibrational progressions. Furthermore, dispersed fluorescence and lifetimes of the strong bands have also been measured.     

Correcting for Spectral Cross‐Talk in Dual‐Color Fluorescence Cross‐Correlation Spectroscopy

Dual‐color fluorescence cross‐correlation spectroscopy (dcFCCS) allows one to quantitatively assess the interactions of mobile molecules labeled with distinct fluorophores. The technique is widely applied to both reconstituted and live‐cell biological systems. A major drawback of dcFCCS is the risk of an artifactual false‐positive or overestimated cross‐correlation amplitude arising from spectral cross‐talk. Cross‐talk can be reduced or prevented by fast alternating excitation, but the technology is not easily implemented in standard commercial setups. An experimental strategy is devised that does not require specialized hardware and software for recognizing and correcting for cross‐talk in standard dcFCCS. The dependence of the cross‐talk on particle concentrations and brightnesses is quantitatively confirmed. Moreover, it is straightforward to quantitatively correct for cross‐talk using quickly accessible parameters, that is, the measured (apparent) fluorescence count rates and correlation amplitudes. Only the bleed‐through ratio needs to be determined in a calibration measurement. Finally, the limitations of cross‐talk correction and its influence on experimental error are explored.     

芳杂环推拉型大分子的多光子上转换荧光性质

用Wittig反应和Heck反应制备了2个新的芳杂环推-拉型荧光大分子聚[(2,5-二苯撑-1,3,4-噁二唑)-4,4'-乙烯撑-交替-N,N'-二(4-苯乙烯撑)]苯胺(P1)和聚[(2,5-二苯撑-1,3,4-噁二唑)-4,4'-乙烯撑-交替-N-乙基-3,6-咔唑乙烯撑](P2). P1和P2的分解温度分别为373和412 ℃, 热稳定性良好. 电化学性能用循环伏安法测定. P1和P2的最高占有分子轨道(HOMO)能级分别为-5.39和-5.81 eV, 最低未占有分子轨道(LUMO)能级分别为-2.81和-3.09 eV. 用飞秒Ti:Sapphire激光器测定了P1和P2的三光子和双光子上转换荧光光谱. 在1250 nm波长激发下, 在四氢呋喃溶液中P1和P2的三光子荧光发射峰分别位于510和491 nm. 在800 nm波长激发下, 在四氢呋喃溶液中P1和P2的双光子荧光发射峰分别位于511和495 nm. 在四氢呋喃溶液中大分子P1和P2单光子荧光发射峰分别位于503 和475 nm, P1和P2的荧光量子产率分别为0.80和0.31. 研究了多光子荧光发射过程的溶剂效应. 结果表明, 溶剂极性增大, P1和P2的多光子荧光发射波长明显红移.     

两种新型F-荧光化学传感器的合成及其性质研究

本文设计合成了N⁶-对甲苯磺酰胺腺嘌呤(I)和邻苯二对甲苯磺酰胺(Ⅱ)两种主体化合物.通过对其与阴离子物种之间相互作用的研究发现,它们在乙腈溶液中和Cl^-、Br^-、NO₃^-、NO₂^-、HSO₄^-、Ac^-、F^-几种阴离子相互作用时,仅对F^-具有专一的选择性识别作用.F^-离子可使I和Ⅱ主体的荧光吸收猝灭并发生红移.通过试验证明,F^-离子和I、Ⅱ主体的识别作用机理是因形成了激基缔合物.     

The use of naphthalene fluorescence probes to study the binding sites on cyclodextrin polymers formed from reaction of cyclodextrin monomers with epichlorohydrin

Three naphthalene-based fluorescence probes were used as guest molecules to study host/guest binding with cyclodextrin (CD) polymer hosts prepared by treating -,-, or -cyclodextrin monomers with epichlorohydrin. The fluorescence data indicate that the binding interaction is much stronger for the probes with the CD polymers than with the CD monomers. Moreover, the fluorophore binding site on the CD polymers is also more hydrophobic than that on the CD monomers. Fluorescence lifetime data from one of the bound probes (2-(N-methylanilino) naphthalene-6-sulfonic acid) suggest that more than one type of binding site may exist on the CD polymers with this probe. A comparison of fluorescence data using different molecular weight ranges of the CD polymers appear to rule out the possibility of a 12 host/guest complex, where the two CD units come from the same polymer chain.     

荧光共轭聚合物在生物大分子检测中的应用*

共轭聚合物因其具有π-电子体系及共轭离域结构,一般都具有优异的发光性能,其发光强度和发射波长会随被检测化合物结构的不同而发生特异性响应,特别是在与被检测物相互作用过程中所产生电荷和能量能够沿共轭分子链进行有效传递,成倍放大这种作用,从而有效提高了检测灵敏度,这比相应的小分子化合物更具有优越性。目前共轭聚合物已被用于开发新型化学、生物传感器,尤其是在生物分子检测方面的应用得到迅速的发展。本文总结了近年来荧光共轭聚合物在生物传感方面的研究进展,主要讨论共轭聚合物在蛋白质、核酸及毒素检测中的应用。     

含羧基中药成分荧光标记方法的建立及优化

用荧光标记技术对含羧基类中药成分进行标记,探索中药成分荧光标记方法,提高其检测灵敏度、为中药药代动力学研究奠定基础。以荧光试剂8-氨基芘-1,3,6-三磺酸三钠盐(APTS)和绿原酸组成研究体系,对标记条件进行优化。反应体系中加入1-乙基-3-(3-二甲氨丙基)碳二亚胺盐酸盐(EDC.HCl)与N-羟基丁二酰亚胺(NHS)可使衍生反应在室温下进行。APTS标记绿原酸的较优反应条件为:绿原酸与APTS的浓度比为1∶5,EDC的浓度为5 mmol/L,NHS的浓度为0.33 mmol/L。以0.1mol/L、pH5.50的NaH2PO4-Na2HPO4为缓冲溶液,绿原酸首先与EDC、NHS避光反应4 h,再与APTS反应4h,即可达到较好的标记效果。此标记方法操作简便,灵敏度高,可以用于含羧基类中药成分的荧光标记研究。     

Circumvention of fluorophore photobleaching in fluorescence fluctuation experiments: a beam scanning approach.

Photobleaching is a fluorophore-damaging process that commonly afflicts single-molecule fluorescence studies. It becomes an especially severe problem in fluorescence fluctuation experiments when studying slowly diffusing particles. One way to circumvent this problem is to use beam scanning to decrease the residence time of the fluorophores in the excitation volume. We report a systematic study of the effects of circular beam scanning on the photobleaching of fluorescent particles as observed in single-photon excitation fluorescence fluctuation experiments. We start by deriving a simple expression relating the average detected fluorescence to the photobleaching cross section of the fluorophores. We then perform numerical calculations of the spatial distribution of fluorescent particles in order to understand under which conditions beam scanning can prevent the formation of a photobleaching hole. To support these predictions, we show experimental results obtained for large unilamellar vesicles containing a small amount of the fluorescent lipophilic tracer DiD. We establish the required scanning radius and frequency range in order to obtain sufficient reduction of the photobleaching effect for that system. From the detected increase in fluorescence upon increase in scanning speed, we estimate the photobleaching cross section of DiD.     

中草药有效成分橙皮甙的固体表面延迟荧光法研究

本文以层析聚配角安膜为基质，用乙酸锂作增强剂，建立了测定痕量中草药有效成分橙皮甙的固体表面延荧光法。该法取样量少，线性范围宽，灵敏度高，操作简便快速。