罗丹明6G荧光猝灭法测定微量硅的研究

研究了酸性介质中，在非离子表面活性剂ＰＶＡ存在下，硅钼杂多酸与罗丹明６Ｇ形成离子缔合物最佳条件，本法灵敏度高，选择性好，操作简便，对钢合金、钢样中硅进行测定，结果满意。     

罗丹明6G催化动力学荧光光度法测定水中氟化物

在弱酸性条件下,NaF对KBrO3氧化罗丹明6G的反应具有催化作用,使罗丹明6G的荧光减弱。基于此建立了测定微量氟化物的催化动力学荧光光度分析新方法。结果表明:罗丹明6G溶液的荧光激发波长和发射波长分别为535nm、556nm,测定的线性范围是0.04~2.8μg/mL,检出限为0.038μg/mL。该法可用于水中微量氟化物的测定。     

罗丹明6G-阴离子表面活性剂体系的共振瑞利散射光谱及分析应用

在pH2．00～3．42的B—R缓冲溶液中,罗丹明6G与十二烷基苯磺酸钠（SD—BS）、十二烷基硫酸钠（SDS）阴离子表面活性剂反应形成离子缔合物,导致共振瑞利散射（RRS）增强,并产生新的RRS光谱,最大RRS峰位于375nm,方法对SDBS、SDS的检出限分别为6ng／mL、5ng／mL,其线性范围分别为0．02～5．6μg／mL、0．02～14．0μg／mL。研究了适宜的反应条件,方法具有较高的灵敏度,用于合成水样和环境水样中阴离子表面活性剂含量的测定,结果满意。     

罗丹明 6G 褪色光度法测定氯酸根

提出了罗丹明６Ｇ褪色光度法测定微量氯酸根离子的新方法,研究了氯酸根在盐酸介质中氧化罗丹明６Ｇ使其褪色的最佳条件。最大吸收波长λｍａｘ在５２５ｎｍ处,其表观摩尔吸光系数ε为１．２２×１０＾５Ｌ·ｍｏｌ＾－１·ｃｍ＾－１,氯酸根的质量浓度在０￣６μｇ／２５ｍＬ范围内符合比耳定律。已用于化学试剂中氯酸根的测定,结果满意。     

罗丹明6G与核酸作用的共振光散射光谱及其分析应用

研究了罗丹明6G（Rh6G）与核酸（ctDNA和yRNA)作用的共振光散光谱（RLS）特征，基于RLS的增强，建立了一种测定核酸的新方法，考察了各种影响因素，在优化条件下确定了RLS强度与ctDNA和yRNA浓度之间的关系，相应的线性范围分别为0.05-37.0μg.mL^-1、0．1－10．0μg.mL^-1，检出限分别为3．0ng.mL^-1和9．5ng.mL^-1。四种合成样品五次平行测定结果的相对标准偏差（RSD）范围为2．0％－3．0％。     

How Graphene Oxide Quenches Fluorescence of Rhodamine 6G

We investigate the fluorescence quenching of Rhodamine 6G (R6G), a well known laser dye with a high fluorescence quantum yield, by as-synthesized graphene oxide (GO) in aqueous solution, which is found to be rather efficient. By means of steady-state and time-resolved fluorescence spectroscopy combined with detailed analysis about the linear absorption variation for this R6G-GO system, the pertinent quenching mechanism has been elucidated to be a combination of dynamic and static quenching. Possible ground-state complexes between R6G and GO during the static quenching have also been suggested. Furthermore, the direction of photoinduced electron transfer between R6G and GO has been discussed.     

CdTe量子点与罗丹明6G间的荧光共振能量转移机理研究

本文在合成水溶性巯基乙酸修饰的CdTe量子点的基础上,研究了CdTe量子点与罗丹明6G之间的荧光共振能量转移.实验结果表明:构建的CdTe量子点(供体)-罗丹明6G(受体)荧光共振能量转移体系在磷酸盐缓冲溶液中有较好的转移效果.当磷酸缓冲溶液pH值为7.4,NaCl浓度为1.0 mol/L时,构建的CdTe量子点-罗丹...     

罗丹明6G荧光猝灭法测定农产品中痕量铁

在稀硫酸溶液中,铁(Ⅲ)与碘化钾反应生成游离碘(以络阴离I-,3 状态存在).所释出的I-,3与罗丹明6G反应生成离子缔合络合物,导致罗丹明 6G 的荧光猝灭.在激发波长 483 nm 及发射波长 551 nm 处测定空白试液及含铁试样溶液的荧光强度F,o及F,s并算得荧光猝灭强度△F.试验结果表明:铁(Ⅲ)的质量浓度在 0.01～0.40 mg·L-1范围内与其相应的荧光猝灭值△F 之问呈线性关系,并测得其检出限(S/N=3)为 0.005 mg·L-1.应用此方法测定了3种农产品试样中的含铁量,并以此试样为基体加入铁(Ⅲ)标准溶液测定了方法的回收率在 95.7%～99.3%之间.     

罗丹明6G的溶液状态和荧光特性的研究

罗丹明6G的荧光性质和它的分子聚集态研究是一个重要的科研领域,所得之k_d值表明水溶液中形成罗丹明6G的双聚体。本文提出用荧光法测定k_d聚合常数,该法用于测定罗丹明6G的溶液状态.实验结果表明罗丹明6G双聚体解聚的某些规律,当单体与双聚体平衡趋于单体时,荧光灵敏度就会增加。     

Metal-organic framework functionalized with deep eutectic solvent for solid-phase extraction of Rhodamine 6G in water and cosmetic products

An NH₂-MIL-53(Al)-DES(ChCl-Urea) nanocomposite was synthesized for extraction and determination of Rhodamine (Rh) 6G from environmental and cosmetic samples. The deep eutectic solvent (DES) was prepared by mixing choline chloride and urea in a mole ratio of 1:2. NH₂-MIL-53(Al)-DES(ChCl-Urea) nanocomposite was synthesized using the impregnation method at a ratio of 60:40 (w/w). The optimum conditions were determined after NH₂-MIL-53(Al)-DES(ChCl-Urea) characterization was performed. The optimum conditions were determined as pH 8, adsorbent amount of 15 mg, total adsorption-desorption time of 6 min, and enrichment factor of 20. The recovery values of the solid-phase extraction method for water and cosmetic samples under optimum conditions were between 95% and 106%. NH₂-MIL-53(Al)-DES(ChCl-Urea) nanocomposite was an economically advantageous adsorbent because of its reusability of 15 times. All analyses were performed using the ultraviolet-visible spectrophotometer. The linear range, limit of detection, and limit of quantification of the method were 100–1000, 9.80, and 32.68 μg/L, respectively. The obtained results showed that the synthesized nanocomposite is a suitable adsorbent for the determination of Rh 6G in water and cosmetic samples. The real sample applications were verified with the high-performance liquid chromatography system.     

Determination of Genistein by Flow‐injection Chemiluminescence Method Based on Ferricyanide Oxidation Sensitized by Rhodamine 6G

A novel flow injection chemiluminescence (FI‐CL) method for the determination of genistein was described. The method was based on the reaction between genistein and potassium ferricyanide in alkaline solution to give weak CL signal, which was dramatically enhanced by rhodamine 6G (Rh G). The CL emission allowed quantitation of genistein concentration in the range 1.0 × 10^?7–4.0 × 10^?5 mol/L with a detection limit (3σ) of 4.2 × 10^?8 mol/L. The relative standard deviation for 11 parallel measurements of 5.0 × 10^?7 mol/L, 4.0 × 10^?6 mol/L and 1.0 × 10^?5 mol/L genistein were 2.59%, 2.40% and 1.48%, respectively. The experimental conditions for the CL reaction were optimized and the possible reaction mechanism was discussed. The method was applied to the determination of genistein in biological fluids.     

Visible light transformation of Rhodamine 6G using tetracarbazole zinc phthalocyanine when embedded in electrospun fibers and in the presence of ZnO and Ag particles

Herein, we report the photocatalytic transformation of Rhodamine 6G (Rh 6G) using tetracarbazole zinc phthalocyanine (TCbZnPc) when alone or when conjugated with ZnO macroparticles (ZnOMPs) and silver nanoparticles (AgNPs), represented as TCbZnPc–ZnOMPs and TCbZnPc–AgNPs, respectively. The photocatalysts were supported onto electrospun polystyrene fibers. The efficiency of TCbZnPc was improved by the presence of both ZnOMPs and AgNPs. HPLC equipped with UV–vis was used to study phototransformation products. The mechanism of transformation was via the N-de-ethylation of Rh 6G.     

Mechanistic Insights into the Fluorescence Quenching of Rhodamine 6G by Graphene Oxide

The fluorescence quenching of Rhodamine 6G (R6G) by graphene oxide (GO) was interrogated by R6G fluorescence measurements using a set of controlled GO samples with varied C/O ratios as the quencher.The carbonyl groups on the GO nanosheet turned to play a dominant role in quenching the R6G fluorescence.The quenching in the static regime can be described by the "sphere of action" model.The significant absorption of the R6G fluorescence by the ground-state complex formed between R6G and GO was identified to be responsible for the static quenching.This work offers helpful insights into the fluorescence quenching mechanisms in the R6G/GO system.     

Ag/Si-NPA基底上共吸附R6G和CV的表面增强拉曼散射

以硅纳米孔柱阵列(Si-NPA)为基底, 采用浸渍沉积技术制备了具有较高表面增强拉曼散射(SERS)活性的Ag/Si-NPA衬底, 并采用扫描电子显微镜和透射电子显微镜对其表面形貌和结构进行了表征. 在此基础上, 选择罗丹明6G(R6G)和结晶紫(CV)2种生物染料分子并采用不同的混合吸附程序对其共吸附状态下的SERS光谱进行了探测. 结果表明, 当2种分子的溶液浓度均为10^-7 mol/L时, 无论采用何种浸渍吸附程序, 其SERS谱中CV的特征拉曼峰都被R6G完全掩盖. 对溶液采用错级配置(R6G和CV的浓度分别为10^-9和10^-7 mol/L)后, 所测SERS谱上获得了分别对应于R6G和CV的分离良好、相对强度匹配、分辨率高的2个SERS特征峰组, 从而有利于简化现实混合探测过程中对SERS特征峰的指认和判断.     

Nanostructured Hybrid Systems with Rhodamine 6G

We synthesized hybrid materials by sol-gel process, using: methyltriethoxysilane, tetraetylorthosilicate and vinyltriethoxysilane, in the presence of Rhodamine 6G. It was synthesized as well organic-inorganic hybrids with addition of tetraisopropyl orthotitanate and maleic anhydride UV-VIS spectra of dye show two absorption peaks at 499 nm (dimer) and 530 nm (monomer). Evaluating FTIR spectra of hybrid films, it was observed a band at 1077 cm^?1, characteristic of the asymmetric Si-O-Si stretching vibration in oligomer. Fluorescence spectra show that tetraisopropyl orthotitanate presence in the composites modifies the nature of the inorganic matrix and affects the interaction with the added dye.     

Characterisation of a new sol-gel precursor for a SiO<Subscript>2</Subscript>-rhodamine 6G hybrid class II material

The entrapment of organic dyes in inorganic solids offers several advantage for solid-state laser applications with respect to the use of liquid or polymer hosts. Among the various inorganic hosts, silica is preferred for its superior mechanical, thermal and optical properties. Organic dyes, such as Rhodamine 6G (Rh6G), can be immobilised in SiO₂ both physically (materials of class I), and by covalent bonds (class II materials). In the past years Rh6G-SiO₂ class I hybrids were prepared. In this work we propose, for the first time, a Rh6G-SiO₂ class II hybrids. We describe the preparation of a suitable sol-gel Rh6G precursor verified by FT-IR analysis and report the characterization of the hybrid materials by means of thermal and porosimetric analysis and optical spectroscopy measurements. The precursor is thermally stable up to ∼250°C, and its optical characteristics (UV-VIS absorbance and photoluminescence, PL) do not change with respect to those of the pristine dye molecule. The PL spectra of the final hybrids show that they are promising candidates for applications in solid state dye lasers.     

A functionalized gold nanoparticles and Rhodamine 6G based fluorescent sensor for high sensitive and selective detection of mercury(II) in environmental water samples

A gold-nanoparticles (Au NPs)-Rhodamine 6G (Rh6G) based fluorescent sensor for detecting Hg (II) in aqueous solution has been developed. Water-soluble and monodisperse gold nanoparticles (Au NPs) has been prepared facilely and further modified with thioglycolic acid (TGA). Free Rh6G dye was strongly fluorescent in bulk solution. The sensor system composing of Rh6G and Au NPs fluoresce weakly as result of fluorescence resonance energy transfer (FRET) and collision. The fluorescence of Rh6G and Au NPs based sensor was gradually recovered due to Rh6G units departed from the surface of functionalized Au NPs in the presence of Hg(II). Based on the modulation of fluorescence quenching efficiency of Rh6G-Au NPs by Hg(II) at pH 9.0 of teraborate buffer solution, a simple, rapid, reliable and specific turn-on fluorescent assay for Hg(II) was proposed. Under the optimum conditions, the fluorescence intensity of sensor is proportional to the concentration of Hg(II). The calibration graphs are linear over the range of 5.0 × 10⁻¹⁰ to 3.55 × 10⁻⁸ mol L⁻¹, and the corresponding limit of detection (LOD) is low as 6.0 × 10⁻¹¹ mol L⁻¹. The relative standard deviation of 10 replicate measurements is 1.5% for 2.0 × 10⁻⁹ mol L⁻¹ Hg(II). In comparison with conventional fluorimetric methods for detection of mercury ion, the present nanosensor endowed with higher sensitivity and selectivity for Hg(II) in aqueous solution. Mercury(II) of real environmental water samples was determined by our proposed method with satisfactory results that were obtained by atomic absorption spectroscopy (AAS).     

吖啶橙-罗丹明6G荧光共振能量转移及其罗丹明6G荧光猝灭法测定蛋白质

研究了吖啶橙(AO)与罗丹明6G(R6G)之间能量转移的最佳条件。在pH=7．20的Tirs-HCl缓冲溶液,十二烷基苯磺酸钠介质中,AO-R6G能够发生有效能量转移,使R6G荧光增强。蛋白质的加入使R6G荧光猝灭,以此建立了利用AO-R6G荧光共振能量转移间接测定蛋白质的新方法。牛血清白蛋白、人血清白蛋白工作曲线线性范围分别为1．0～31和1．0—30mg／L;检出限分别为0．32和0．33mg／L;平行6次测定相对标准偏差为1．1％～2．0％;回收率为96．7％～103．2％。此方法的稳定性好,选择性高,用于人血清试样中总蛋白含量的测定,与常用的双缩脲法基本一致。     

Classification of single-molecule surface-enhanced resonance Raman spectra of Rhodamine 6G from isolated Ag colloidal particles by principal component analysis

Surface enhanced resonance Raman (SERR) spectra of Rhodamine 6G are measured from single isolated Ag particles and analyzed by using a chemometrics technique, principal component analysis (PCA). The Ag particles are incubated with various amounts of R6G yielding the ratio of Ag particles to R6G molecules from 1:1 to 1:1000. Acquired SERR spectra are considered due to a single or very few R6G molecules. PCA is used to determine the number of chemically distinguishable species that contribute to the measured SERR spectra. A simple clustering tool, score bi-plot, is then inspected on grouping of the SERR spectra. The spectra are found to be largely similar except for the variability in the intensity and position of the bands that is believed to be correlated with the lifetime of the strong enhancement at specific places on an Ag surface. The spectra from four different Ag particles carrying more than 1000 R6G molecules are, however, unambiguously separated. Different aspects of the applied data analysis method and physicochemical perspective of the results are discussed.     

光致电子转移对Rhodamine 6G基态分子结构影响的非共振Raman光谱研究

基于非共振Raman 光谱和量子化学计算, 研究了在纯电子给体N,N-二乙基苯胺(DEA)溶剂中Rhodamine 6G (Rh6G⁺)基态分子结构的变化, 这有利于理解该体系中的光致分子间电子转移(PIET). 与PIET相耦合的所有振动模式已被确定和指认. 结果表明: 对应于氧杂蒽环且位于675 cm^-1处最主要的振动模式对PIET 有着至关重要的贡献; 通过与电荷转移复合物(Rh6G/DEA⁺)的发色团芳香族环的C―C伸展振动模式作比较, C=C伸展振动对PIET的影响更敏感. 本文的研究工作能为具有合适电子转移特性的光伏器件中分子结构或溶剂环境的设计提供新颖的观点.