光谱法研究山奈酚与ct-DNA的相互作用

利用紫外-可见吸收光谱和荧光光谱研究了黄酮类化合物山奈酚与小牛胸腺DNA（ct-DNA）之间的相互作用。随着DNA的加入,山奈酚的吸收光谱逐渐发生明显的红移和减色效应,通过双倒数法拟合分析,得到山奈酚与ct-DNA的结合常数为1.2×10^4。山奈酚自身荧光很弱,与DNA结合后其荧光明显增强,表明山奈酚可以作为荧光探针来开展与生物大分子相互作用的研究。     

石油开采和冶金行业污水中矿物油的荧光和红外光谱法分析

针对建立测定水中矿物油含量的荧光光谱法,选择了来自石油开采和冶金行业的4个典型企业,分别提取了所排放污水的三维荧光光谱及荧光特征峰,并分析两个行业污水矿物油含量与它们荧光光谱数据之间的对应关系,结果表明石油开采行业污水中的矿物油含量要高于冶金行业.同时国标法的红外光谱法也佐证了这一结果.因此,荧光光谱法可在一定范围内应...     

农药荧光寿命测试系统的原理与设计

介绍荧光的产生、荧光寿命的产生机理以及荧光寿命测量的基本原理。设计了一种利用直接记录法(光子计数法)测量农药荧光寿命的测试系统。该系统针对待测样品的特性，选用了相应的脉冲光源、光学元件和半导体探测器等器件，优化了各器件的工作参数，进行了简易而又科学的模块化设计，并对西维因农药的荧光寿命在无激励光干扰情况下进行了实际测试，测得了西维因溶液在500μg／L浓度时的荧光衰减曲线和荧光寿命(0.30～0.40ns)。结果表明，该系统具有结构简易、操作方便的优点，能测量100ps级的荧光寿命，适合于对能发荧光的农药进行荧光寿命的定量测量。     

色氨酸和酪氨酸的三维荧光光谱特征参量提取

氨基酸是维持生命活动的重要物质,而色氨酸和酪氨酸又是天然氨基酸中重要的发光组分,应用荧光光谱法对其进行测量和分辨具有重要的意义。文章用美国Pekin-Elmer LS55型荧光分光光度计,对色氨酸和酪氨酸的三维荧光光谱进行了测量。将测量的数据用激发-发射-荧光强度的三维坐标表示,得到三维荧光谱图,但色氨酸和酪氨酸存在共性峰,通过波峰位置简单地来辨别两种混叠的物质很有难度。以数理统计概念为基础,提取该三维荧光光谱的特征参数,得到两种物质荧光光谱中最相关的信息,可以解决两种物质光谱混叠的分辨问题。结果表明,色氨酸和酪氨酸的三维荧光光谱平均值、标准差、原点矩、混合中心矩等参数差值百分比分别为330.37%, 102.86%, 329.16%, 329.63%,区别较大;而边际分布、相关系数值差值百分比仅为10.61%和2.40%。因而平均值、标准差、原点矩、混合中心矩可作为敏感特征参数,用其分辨谱图混叠的色氨酸和酪氨酸是可行的。这种“数学预提取”的三维光谱分析法可以找出组分之间的敏感特征参量,能够取代传统的三维荧光光谱分析法。     

Fluorescence Decay of Natural Organic Matter (NOM)—Influence of Fractionation, Oxidation, and Metal Ion Complexation

Time-resolved fluorescence measurements of aquatic natural organic matter (NOM) derived from different origins were performed using the time-correlated single-photon counting technique. The obtained experimental data were analyzed with nonlinear least-squares (NLLS) algorithms. The results of a global analysis with three exponential decay terms were compared with the results obtained in a distribution analysis (exponential series method; ESM). Fulvic acid fractions from a bog lake water, from a brown coal production effluent, and from a soil seepage water as well as NOM from a municipal waste water were investigated. The influence of the emission wavelength on the NOM fluorescence decay was monitored. Furthermore, the influence of fractionation using size exclusion chromatography, of ozonation, and of metal ion complexation on the fluorescence decay of the NOM samples was investigated.     

Fluorescence of jet-cooled naphthalene: Emission spectra, lifetimes and quantum yields

Fluorescence spectra of naphthalene, C₁₀H₈, were obtained in the laboratory under conditions which provide an appropriate simulation of the cometary conditions: super-cooled gas phase molecules in a collision-free environment. Five spectra were recorded, the excitation energies ranging from 1422 to 5293 cm⁻¹ above the first electronic state S₁ at 32 020 cm⁻¹. A comparison with previous jet-cooled naphthalene fluorescence spectra obtained by Beck et al. [1] and Hermine [2] shows that the former results are not consistent with the present ones. Spectra obtained by Beck et al. show weaker intensities at greater wavelengths compared to those obtained by Hermine and ourselves. We also measured the fluorescence lifetimes by recording the fluorescence decay as a function of time after the excitation of the molecules by monochromatic lasers and deduced the fluorescence quantum yields. A synthetic emission spectrum under solar irradiation is obtained for astrophysical implications.     

血清白蛋白与小分子化合物相互作用的荧光光谱研究

以牛血清白蛋白-Triton X-100和牛血清白蛋白-盐酸西布曲明两个体系为实例,考察了以血清白蛋白和小分子化合物为荧光检测对象所获得的相互作用信息的差异。发现两种方法获得的分子间结合常数差异显著,说明在以血清白蛋白为检测对象的传统荧光光谱法中,以色氨酸基团的荧光光谱所表达的信息来代表整个蛋白分子的相互作用信息是不准确的。文章提出了以荧光小分子化合物为检测对象的改进荧光光谱方法和荧光背景扣除方法,前者能全面表达相互作用过程中分子的整体信息,后者实现了荧光光谱交叠体系的荧光光谱法相互作用分析。     

苹果汁中吡虫啉农药残留荧光检测研究

根据有机物受激发射荧光的基本原理,研究了杀虫剂吡虫啉的荧光特性。利用荧光光谱仪对吡虫啉及苹果汁-吡虫啉混合体系进行了研究,得到了苹果汁中不同农药含量下的荧光谱图,分析了荧光强度与农药含量的关系。实验表明：当234 nm作为激发波长时,苹果果汁几乎没有荧光峰出现,而吡虫啉有很强的荧光,荧光峰值在373 nm左右。向果汁中逐量添加吡虫啉药液后,得到苹果汁中吡虫啉含量最佳预测模型,决定系数达到0.996 74,预测准确率高于90%。研究结果表明,利用荧光光谱法直接对苹果果汁中农药残留检测是快速和可行有效的。     

Synthesis of Fluorescent Silica Nanoparticles and Their Applications as Fluorescence Probes

This paper presents the synthesis of organic dye molecules embedded silica nanoparticles by Stöber method and their applications as fluorescence probes in cell imaging. By modifying the surface of fluorescent silica nanoparticles (FSNs) with amino, biologically functionalized and monodisperse FSNs can be obtained. In this work, FSNs were conjugated with monoclonal anti-Carcinoembryonic Antigen (anti-CEA) antibody via covalent binding. The antibody-conjugated FSNs can be used to label the SPCA-1 cells successfully, demonstrating that the application of FSNs as fluorescence probes in fluorescence imaging and bioassay would be feasible.     

土壤中有机农药荧光检测研究

根据有机物受激发荧光的基本原理,研究了氨基甲酸酯类有机杀虫剂西维因的荧光特性。利用荧光光谱对西维因及其水解物的溶液进行了研究,获得了不同浓度条件下的荧光谱图,考察了荧光强度与浓度的关系。结果表明,西维因及其水解物在一定的土壤环境中受紫外光激发时也能够发出很强的荧光,而且在溶剂中和土壤中的荧光光谱基本相同。它们的荧光光谱波长都位于可见光区的400～750 nm波段之间,波形平滑,分辨率高,适于农药的定性定量分析。实验证明利用荧光光谱法对土壤中的有机农药进行直接或间接的检测分析是可行的。     

奥硝唑对映体与牛血清白蛋白的相互作用研究

利用荧光光谱法分别研究了S-奥硝唑(S-ONZ)和R-奥硝唑(R-ONZ)与牛血清白蛋白(BSA)相互作用机制。结果表明S-ONZ和R-ONZ均能猝灭BSA的荧光,属于静态猝灭。根据Stern-Volmer方程和结合反应方程式分别计算出了反映药物与BSA作用机制的参数:猝灭常数KSV,结合常数KA,结合位点数n。由求得的热力学参数(ΔH、ΔS和ΔG)判断了药物与BSA之间作用力主要类型为静电作用。此外,本文同时考察了溶液pH值和异丙醇对药物和BSA之间作用力类型及作用强度的影响。实验方法简便、快速,实验结果初步阐明药物与BSA作用机制,有助于解释奥硝唑不同对映体的药效差异。     

多环芳烃时间分辨荧光光谱特性研究

利用时间分辨荧光光谱技术,研究了菲、荧蒽、芴、蒽、芘等五种多环芳烃的荧光时间分辨发射光谱特性。以289 nm受激拉曼光作为激发光源,研究了289 nm激发光作用下五种多环芳烃的延时特性和门宽特性。并以多环芳烃随延时时间的荧光峰强度衰减关系曲线,得到菲、荧蒽、芴、芘的荧光寿命分别为37.0, 32.7, 10.9, 147.0 ns。不同荧光物质具有特定的荧光光谱特性,多环芳烃时间分辨荧光光谱特性的研究可以为复杂水体中不同种类多环芳烃的诊断提供依据。     

甲醇和乙醇的三维荧光光谱特性研究

为阐明甲醇和乙醇的光谱学特性,建立两者快速的辨析方法。采用三维荧光光谱,对甲醇和乙醇的荧光特性进行了研究。分析结果显示,甲醇的三维荧光光谱中出现了两个特征荧光峰,其荧光强度在甲醇体积浓度小于15%时与其浓度成正相关,乙醇的三维荧光光谱中出现了一个完整的特征荧光峰,其荧光强度在乙醇体积分数小于50%时与乙醇浓度成相关,甲醇比乙醇具有更高的荧光效率,以甲醇为有机溶剂研究化合物的荧光特性时,需要考虑甲醇的本底荧光。甲醇和乙醇的特征荧光峰位置差别较大,前者特征荧光峰出现在225/35 0nm和250/375nm处,而后者特征荧光峰位于240/310nm,据此可以有效辨析两种醇。     

The fluorescence spectra of pharmaceutical compounds under two-photon excitation

Spectra of two-photon-excited fluorescence in pharmaceutical crystalline compounds were obtained and studied as functions of the pump power and delay time. Stimulated fluorescence was observed in polycrystalline Novocaine under high-power pumping. The spectra of two-photon-excited fluorescence in pharmaceutical compounds are localized within the wavelength range of 270–480 nm. The most intense fluorescence was observed in the Novocaine polycrystals. The therapeutic effect of diphenylhydramine and sulfanilamide is attributed to the fact that the energy of optical quanta of the fluorescence emission in these substances is higher than the energy of excited π-electrons in tryptophan and nucleotides. The data obtained for the spectra of the pharmaceutical substances studied can be used to solve analytical problems related to identification of the composition and properties of composite pharmaceutical substances.     

鲜红斑痣光动力治疗的荧光光谱监测

应用荧光光谱技术监测了鲜红斑痣(PWS)光动力治疗(PDT)中的光敏剂血药浓度与光产物生成。以532 nm倍频Nd∶YAG激光器作为PDT照射光源与荧光激发光源,以光谱仪与ICCD采集荧光光谱。在系统验证实验中,构建含有血卟啉单甲醚(HMME)的小鼠正常皮肤的荧光基本光谱,通过最小二乘光谱拟合区分HMME荧光(624 nm)与光产物荧光(652 nm)。含有PSD-007的病人患区荧光光谱拟合采用相同基本光谱,获得不同病人个体具有显著差异的光敏剂血药浓度曲线与光产物生成漂白曲线。所建立的荧光光谱监测系统与光谱拟合方法可为PDT精确量化剂量学方法的建立提供技术手段,所得结果有利于制定个性化的PDT治疗方案。     

Fluorometric Determination of Bopindolol and Celiprolol in Pharmaceutical Preparations and Biological Fluids

Two sensitive fluorometric methods were developed for the determination of both bopindolol malonate (BOP) and celiprolol HCl (CLP) based on measuring their native fluorescence in methanol and acetonitrile, respectively. For BOP, the fluorescence was measured at 316?nm after excitation at 278?nm. The proposed method was successfully applied to the assay of commercial tablets as well as content uniformity testing. For CLP, the fluorescence was enhanced by the addition of carboxymethylcellulose solution and measured at 455?nm after excitation at 339?nm. The method was successfully applied to the analysis of CLP in tablets and biological fluids. In both methods, interference likely to be introduced from co-formulated, co-administered, or chemically related drugs was studied. The results were statistically compared with those obtained by reference methods and were found to be in good agreement.     

Flow cytometric discrimination of phytoplankton classes by fluorescence emission and excitation properties

The ataxonomic discrimination of phytoplankton species on the basis of fluorescence data obtained by multiwavelength excitation in combination with wavelength selective detection in flow cytometry is demonstrated. The discrimination is based on differences in pigment composition between the species, which are reflected in their spectral characteristics. Classification can be done both by making use of the absolute fluorescence intensities and with fluorescence parameter ratios. The latter approach has the advantage that size-related effects and instrument fluctuations are reduced to a large extent. Photoadaptation does influence the absolute as well as the ratioed parameters that are obtained but does not impede the classification into major ataxonomic groups.     

铽配合物荧光及在农用光波长转换塑料薄膜中的应用

选择荧光效应强的稀土元素铽,以磺基水杨酸作为第一配体,以聚乙烯醇、聚乙二醇2000等为协配体,对乙醇溶液和水溶液两个体系中形成的配合物荧光进行了研究。试验确定了铽、磺基水杨酸以及聚乙烯醇、聚乙二醇2000为优良协配体的最佳用量。进一步研究发现,表面活性剂的加入对不同配合物的荧光均会产生增强效果,十二烷基磺酸钠效果最好;同时探索了酸度对体系荧光强度的影响。对于获得的铽-磺基水杨酸-聚乙烯醇配合物,其荧光激发波长为342 nm,而荧光发射波长为545 nm,将该配合物以适当比例掺加到农用塑料薄膜中,制备出可以使太阳光的紫外部分转换为作物光合作用需要的绿光的稀土光转换膜。     

光谱法研究甲氨喋呤与牛血清白蛋白的相互作用

用荧光和紫外吸收光谱法,研究了抗癌药物甲氨喋呤(MTX)与牛血清白蛋白(BSA)的相互作用。结果表明：在生理条件下,甲氨喋呤对牛血清白蛋白荧光有较强的猝灭作用,其猝灭方式为静态猝灭。根据猝灭结果,求出了不同温度下反应的结合常数及反应热力学参数,并据此确定了它们相互作用的主要形式。