吖啶橙-罗丹明B荧光共振能量转移猝灭法测定砷

研究了利用吖啶橙(AO)-罗丹明B(RB)共振能量转移荧光猝灭法测定痕量砷的方法。在λ_ex/λ_em=470/580 nm,0.016 mol·L-1 H₂SO₄溶液中,十二烷基苯磺酸钠(DBS)存在下,吖啶橙-罗丹明B能够发生有效的能量转移,使罗丹明B的荧光强度大大增强;在酸性条件下,砷与钼酸铵生成砷钼杂多酸使能量转移体系罗丹明B的荧光猝灭。利用吖啶橙-罗丹明B能量转移荧光猝灭法测定痕量砷,砷在0.01～0.25 mg·L-1范围内与罗丹明B荧光猝灭程度呈良好的线形关系,方法检出限为2.56 μg·L-1。该方法用于茶叶中痕量砷的测定,相对标准偏差为0.48%～0.64%,回收率为98%～103%,结果满意。     

罗丹明B荧光猝灭法测定微量溴酸根离子

在盐酸介质中,溴酸根对罗丹明B的褪色作用,且褪色的程度与溴酸根的量有关,从而建立了测定溴酸根的新方法.方法的线性范围为0.00-17.00μg/25mL,检出限为9.05ng/mL,用于化学试剂中微量溴酸根的测定,结果满意.     

氧化石墨烯如何猝灭罗丹明6G的荧光

考察了水相溶液中氧化石墨烯对罗丹明6G的高效荧光猝灭．借助稳态及时间分辨荧光光谱测量,结合对该二元体系线性吸收谱变化的细致分析,澄清了相关荧光猝灭机理,即动态猝灭与静态猝灭的联合猝灭机制．提出在静态猝灭过程中罗丹明6G与氧化石墨烯所形成的可能的基态复合物,并进一步讨论了二者之间的光致电子转移过程．     

罗丹明B荧光猝灭法测定水中痕量亚氯酸根

在有KI存在的乙酸钠-HCl酸性缓冲溶液中,用520 nm光激发罗丹明B(RhB),在580 nm处有一个荧光峰。当有亚氯酸根(ClO-2)存在时,罗丹明B荧光峰发生猝灭。亚氯酸根浓度在0.021 8～0.51 μg·mL-1范围内与荧光猝灭强度成线性关系,据此建立了一个简便灵敏的亚氯酸根荧光分析新方法,用于测定合成水样中(ClO-₂)的分析,结果令人满意。     

吖啶橙-PAR-钒(Ⅴ)能量转移荧光猝灭法的研究及分析应用

在pH 5.5的Na2HPO4-柠檬酸缓冲溶液中,吖啶橙（AO）与PAR-钒（Ⅴ）络合物之间发生有效的能量转移,使吖啶橙526 nm处的荧光猝灭,据此建立了能量转移荧光测定痕量钒的新方法。实验表明,在pH5.5的3.0×10^-5mol.L^-1AO-4.0 mg.L^-1PAR体系中,钒的含量c在0.12-0.5μg.mL^-1范围内与荧光猝灭强度ΔF呈良好线性关系,线性回归方程为ΔF=165.4c＋2.5,方法检出限为0.0045μg.mL^-1,相对标准偏差为0.6%。该荧光猝灭反应15 min内完全,其相对荧光强度在2.5 h内基本保持不变。用该方法测定生物样品中钒的含量,相对误差小于5%,结果满足痕量分析要求。     

吖啶橙-PAR-钒(V)能量转移荧光猝灭法的研究及分析应用

在pH 5.5的Na2HPO4柠檬酸缓冲溶液中,吖啶橙(A0)与PAR-钒(V)络合物之间发生有效的能量转移,使吖啶橙526 nm处的荧光猝灭,据此建立了能量转移荧光测定痕量钒的新方法.实验表明,在pH5.5的3.0×10-5mol·L-2AO-4.0 mg·L-1PAR体系中,钒的含量c在0.12～0.5μg穖l-1范围内与荧光猝灭强度△F呈良好线性关系,线性回归方程为△F=165.4c+2.5,方法检出限为0.004 5.μg穖L-1,相对标准偏差为0.6%.该荧光猝灭反应15 min内完全,其相对荧光强度在2.5 h内基本保持不变.用该方法测定生物样品中钒的含量,相对误差小于5%,结果满足痕量分析要求.     

十二烷基苯磺酸钠胶束中吖啶橙与罗丹明6G间的能量转移机理研究

以吖啶橙(AO)与罗丹明6G(R6G)为例讨论了胶束介质中碱性荧光染料间相互作用的机理。在十二烷基苯磺酸钠水溶液中,吖啶橙与罗丹明6G染料分子间相互作用发生有效能量转移。在不同温度下,通过对能量转移体系研究,初步证明吖啶橙与罗丹明6G间发生能量转移引起吖啶橙的荧光猝灭为静态猝灭过程。通过热力学参数的计算,得出能量转移体系的结合力主要为静电引力。同时也对转移体系的能量转移效率,结合位点数和结合距离进行了计算。     

CdTe量子点-罗丹明B荧光共振能量转移猝灭法测定金银花中的微量铜

研究CdTe量子点(供体)和罗丹明B(受体)之间荧光共振能量转移的最佳条件,建立了荧光共振能量转移猝灭法测定金银花中微量铜的新方法.采用十六烷基三甲基溴化铵,在pH 6.00的Tris-HCl缓冲液中,Cu2+能对能量转移体系中罗丹明B荧光峰强猝灭从而测定铜的含量.Cu2+浓度在1.3×10-4～3.1×10-2 μg...     

罗丹明B同步荧光猝灭法测微量磷的条件研究

本文研究了罗庆明Ｂ－磷钼杂多酸离子缔合物体系的荧光特性及测定方法，对实验条件进行了优化选择，并引入非离子表面活性剂ＯＰ对体系增敏，增稳。本法用于黑色食品中磷的测定，结果满意。     

罗丹明-四苯硼钠体系反荧光猝灭法测定盐酸西替利嗪

四苯硼钠对罗丹明B具有荧光猝灭作用,使荧光信号强度减弱甚至消失,而盐酸西替利嗪对罗丹明B-四苯硼钠体系具有反猝灭作用,又能使该体系荧光信号增强,且荧光信号增强程度与药物浓度成线性关系.该文以491 nm为激发波长,以610 nm作发射波长,测量空白液与试液荧光强度之差△F=F1-F0,根据△F值与溶液中的盐酸西替利嗪浓...     

PAR-吖啶黄能量转移荧光猝灭法测定痕量铁(Ⅱ)的研究

对 4 (2 吡啶偶氮 ) 间苯二酚 (PAR)与吖啶黄间荧光能量转移进行了探讨 ,研究了其能量转移的最佳条件 ,并应用该体系测定痕量铁 (Ⅱ ) ,由此建立了能量转移荧光测定痕量铁的新方法。在λex/em =46 5nm/5 0 5nm ,十二烷基硫酸钠 (SDS)作用下 ,pH =9 2时 ,吖啶黄与PAR 铁 (Ⅱ )络合物间能发生有效能量转移 ,使吖啶黄的荧光猝灭。铁的量在 0～ 10 μg·L-1范围内呈良好的线性关系。最低检出限 0 0 6 μg·L-1。该方法用于水样、发样中痕量铁的测定 ,结果满意。     

Fluorescence resonance energy transfer between acridine orange and rhodamine 6G and analytical application in micelles of dodecyl benzene sodium sulfonate

A new method for the determination of erythromycin by energy transfer fluorescence quenching of acridine orange (AO)—rhodamine 6G (R6G) in micelles solution studied and established. It was found that the effective energy transfer could occur between AO and R6G in the dodecyl benzene sodium sulfonate at and Britton-Robinson buffer (BR, pH=5.72). The fluorescence intensity of R6G had been increased sharply. Erythromycin diminished the fluorescence intensity of R6G. The detection limit was up to 0.316 mg l⁻¹. The range of determining concentration of erythromycin was 0.75-15 mg l⁻¹. The relative standards deviation were 0.66-1.38% for six parallel determinations of erythromycin. The recoveries of erythromycin were 96.95-101.41%. The measurement was applied to the determination of capsules of erythromycin with good results.     

吖啶橙荧光探针法测定人体尿液中的DNA

因吖啶橙(Acridine Orange,简称AO)在十二烷基苯磺酸钠(Dodecylbenzene Sulfonic Acid Sodiumsalt以下简称SDBS)介质中存在形态之间的平衡,而DNA(deoxyribonucleic acid)的加入所起作用也象表面活性剂一样起到有序化介质的作用,即DNA的加入可使AO的平衡发生移动,导致体系荧光增强,其荧光强度与DNA的浓度在一定的范围内呈线性关系,从而建立了测定DNA的新的灵敏方法。本法的荧光激发波长为506 nm,发射波长为529 nm,激发和发射狭缝均为5 nm。对于鱼精子DNA(Fish sperm DNA以下简称fsD-NA),线性范围为0-10 μg·mL-1,方法的最低检出限为0.088μg·mL-1,本法成功应用于人体尿液中DNA的临床测定。     

氧化石墨烯猝灭罗丹明6G荧光的机理研究

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.     

Homogeneous Detection of Specific DNA Sequences by Fluorescence Quenching and Energy Transfer

The use of fluorescence quenching and energy transfer in DNA hybridization assays is reviewed. Placement of DNA probe labels within interacting distances by hybridization of DNA probes to target DNA or to one another allows rapid homogeneous analysis of specific DNA sequences. Due to the inherently lower sensitivity relative to heterogeneous assays, the fluorescence assays have been coupled with DNA amplification methods such as PCR to provide highly sensitive, clinically relevant homogeneous assays which can be performed in closed systems.     

基于银纳米三角片与罗丹明6G的荧光共振能量转移法检测钴离子

以罗丹明6G和牛血清白蛋白的复合物为荧光探针,银纳米三角片为猝灭剂,研究了银纳米三角片与荧光复合物的荧光共振能量转移现象,建立了测定钴离子的荧光分析法。研究发现,一定浓度的荧光复合物与银纳米三角片混合后,由于荧光复合物在银纳米三角片上吸附而发生荧光共振能量转移,荧光猝灭达到80%左右。当钴离子存在时,银纳米三角片与罗丹明6G荧光共振能量转移被破坏,荧光逐渐恢复。随着钴离子浓度的增加,体系荧光值的恢复率(I/I₀)与钴离子的浓度(c_Co2+)有良好的线性关系,线性回归方程为I/I₀=1.054+21.72 c_Co2+,相关系数r2为0.996 2。通过对自然水样进行加标回收检测,实现了钴离子的定量检测,回收率在90.4%～115.1%之间。建立了一种可靠的选择性检测钴离子的荧光分析方法。     

维生素B12与牛血清白蛋白相互作用的荧光法研究

用荧光光谱法和紫外吸收光谱法研究了生理条件下维生素B12与牛血清白蛋白之间的相互作用。结果表明,维生素B12对牛血清白蛋白的荧光有猝灭作用,其猝灭过程属于静态猝灭。通过计算得出维生素B12与牛血清白蛋白的结合常数及结合位点数。根据Foerster非辐射能量转移理论,测得维生素B12与牛血清白蛋白的能量转移效率E=0.1091,维生素B12与牛血清白蛋白的结合位置距离212位的色氨酸残基为6.29nm。同时采用同步荧光光谱法研究了维生素B12对牛血清白蛋白构象的影响。     

Competition Between Energy Transfer Quenching and Chelation Enhanced Fluorescence in a Cu (II) Coordinated Conjugated Polymer System

An investigation of the mechanism of the fluorescence quenching by Cu²⁺ for a conjugated polymer system initially designed as a fluorescence “turn-on” chemosensor based on chelation enhanced fluorescence (CHEF) is described in this paper. Unlike all other metal cations tested, the polymer/Cu²⁺ hybrid system with a 1:1 ratio between the receptor and Cu²⁺ has only weak fluorescence with λ_max = 490 nm and a quantum yield of 0.004 in THF at room temperature. In solvent glasses at 77 K the fluorescence remained quenched suggesting that the quenching mechanism was due to energy transfer between the Cu²⁺ and the conjugated polymer backbone. The energy transfer quenching competes effectively with the electron transfer involved in the CHEF resulting in a more selective chemosensory system. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.