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在pH 8.0的缓冲体系中,肝素使得罗丹明6G的荧光发生明显猝灭,罗丹明6G的荧光猝灭程度在一定范围内与肝素的浓度成正比,据此建立了荧光猝灭法测定痕量肝素的方法,并对体系的荧光猝灭机理进行了讨论。体系的激发波长为482 nm,发射波长为560 nm,线性范围为0.05~3.0 mg/L,检出限为6.1μg/L。方法已应用于肝素钠注射液中肝素含量的测定。 相似文献
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罗丹明6G荧光猝灭法测定农产品中痕量铁 总被引:1,自引:0,他引:1
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. 相似文献
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在HAc-NaAc缓冲溶液中,罗丹明类染料罗丹明6G(Rh6G)、罗丹明B(RhB)和丁基罗丹明(b-RhB)分别在553,582和589 nm处产生一个较强的荧光峰。加入异烟肼(INH)后,由于异烟肼分别与Rh6G,RhB和b-RhB发生作用,从而使得3种体系的荧光均发生猝灭。在最佳实验条件下,异烟肼浓度分别在0. 10~20μg/mL,0. 10~25μg/mL和0. 50~22μg/mL范围内与各体系的荧光强度改变值(!F)之间呈良好的线性关系,且3种体系的检出限分别为9. 04,21. 7和20. 4 ng/mL。据此,建立了一种荧光猝灭法测定药物中异烟肼含量的分析方法。 相似文献
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罗丹明6G荧光猝灭法测定微量硅的研究 总被引:4,自引:0,他引:4
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。 相似文献
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荧光光度法测定痕量过氧化氢——基于对罗丹明6G的荧光猝灭效应 总被引:2,自引:0,他引:2
高甲友 《理化检验(化学分册)》2008,44(2):189-190
过氧化氢是一种强氧化剂,可作为漂白剂、消毒剂、脱氧剂等使用,大气及雨水中的过氧化氢还与酸雨的形成有密切的关系. 相似文献
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Nucleotide-specific fluorescence quenching in fluorescently labeled DNA has many applications in biotechnology. We have studied
the inter- and intra-molecular quenching of tetramethylrhodamine (TMR) by nucleotides to better understand their quenching
mechanism and influencing factors. In agreement with previous work, dGMP can effectively quench TMR, while the quenching of
TMR by other nucleotides is negligible. The Stern-Volmer plot between TMR and dGMP delivers a bimolecular quenching constant
of K
s
= 52.3 M−1. The fluorescence of TMR in labeled oligonucleotides decreases efficiently through photoinduced electron transfer by guanosine.
The quenching rate constant between TMR and guanosine was measured using fluorescence correlation spectroscopy (FCS). In addition,
our data show that the steric hindrance by bases around guanosine has significant effect on the G-quenching. The availability
of these data should be useful in designing fluorescent oligonucleotides and understanding the G-quenching process. 相似文献
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The fluorescence behaviour of the flavins riboflavin, flavin mononucleotide (FMN), flavin adenine dinucleotide (FAD), and lumiflavin in aqueous solution at pH 8 in the presence of the reducing agents β-mercaptoethanol (β-ME), dithiothreitol (DTT), and sodium nitrite (NaNO2) is studied under aerobic conditions. The fluorescence quantum yields and fluorescence lifetimes are determined as a function of the reducing agent concentration. For all three reducing agents diffusion controlled dynamic fluorescence quenching is observed which is thought to be due to photo-induced reductive electron transfer. For DTT additionally static fluorescence quenching occurs. 相似文献
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以3-巯基丙酸作为稳定剂,在水溶液中合成了CdTe量子点;采用荧光光谱法初步研究了栀子甙对巯基丙酸稳定的CdTe量子点的荧光淬灭作用,考察了量子点浓度、pH、反应时间等多种因素对量子点-栀子甙体系荧光强度的影响,确定了测定栀子甙的最佳实验条件;并初步探讨了栀子甙与该量子点相互作用的可能反应机理.结果表明,在最佳实验条件下,巯基丙酸稳定的CdTe量子点对栀子甙检测的线性范围为2×10-7~4×10-6 mol/L,检出限为1.4×10-7 mol/L,相对标准偏差为0.355%;且常见的金属阳离子、糖类和氨基酸对栀子甙的测定无显著影响.总体而言,该方法可用于人体体液中栀子甙的检测,且两者的作用过程可初步推断为动态淬灭过程. 相似文献
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M. V. Kvach S. V. Gontarev I. A. Prokhorenko I. A. Stepanova V. V. Shmanai V. A. Korshun 《Russian Chemical Bulletin》2006,55(1):159-163
Synthesis of a phosphoramidite reagent for the preparation of oligonucleotides labeled at the 5′-end with a fluorescent dye,
3,3,3′,3′-tetramethyl-2,2′-indodicarbocyanine, is described. The efficiency of this reagent is confirmed by the synthesis
of several labeled oligonucleotides.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 154–158, January, 2006. 相似文献
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The fluorescence spectra of polysilanes can be quenched by halohydrocarbons. The quenching processes are not simple diffusion-controlled processes but involve both dynamic and static quenching processes. The fluorescence of some electron-accepting compounds can be quenched by polysilanes. The quenching mechanism is mainly caused by charge transfer interaction between fluorophores and quenchers. All the results proved that the rapid energy migration along the polysilane main chain does really exist in the excited state whether it is homopolymer or copolymer. 相似文献
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Roksana Markiewicz Jagoda Litowczenko Jacek Gapiski Anna Wo
niak Stefan Jurga Adam Patkowski 《Molecules (Basel, Switzerland)》2022,27(3)
Measurement of the nitric oxide (NO) concentration in living cells in the physiological nanomolar range is crucial in understanding NO biochemical functions, as well as in characterizing the efficiency and kinetics of NO delivery by NO-releasing drugs. Here, we show that fluorescence correlation spectroscopy (FCS) is perfectly suited for these purposes, due to its sensitivity, selectivity, and spatial resolution. Using the fluorescent indicators, diaminofluoresceins (DAFs), and FCS, we measured the NO concentrations in NO-producing living human primary endothelial cells, as well as NO delivery kinetics, by an external NO donor to the immortal human epithelial living cells. Due to the high spatial resolution of FCS, the NO concentration in different parts of the cells were also measured. The detection of nitric oxide by means of diaminofluoresceins is much more efficient and faster in living cells than in PBS solutions, even though the conversion to the fluorescent form is a multi-step reaction. 相似文献
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Photoinduced electron-transfer system of anthracene-N,N-di-ethylaniline (DEA) was studied in the oil in water (O/W) mi-croemulsions formed by SDS (sodium dodecyl sulfate),BA (benzyl alcohol) and H2O.The time-resolved fluorescence study showed that the fluorescence quenching of the excited anthracene by DEA occurs at the interface of the O/W mi-croemulsions.Besides as the quencher of the excited anthracene,N,N-diethylaniline could act as a cosurfactant to change the structures of the microemulsions,just as BA did.The quenching rate constants for the different structures of the system were determined. 相似文献
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Escaja N Gómez-Pinto I Viladoms J Rico M Pedroso E González C 《Chemistry (Weinheim an der Bergstrasse, Germany)》2006,12(15):4035-4042
We have investigated the molecular interaction between cyclic and linear oligonucleotides. We have found that short cyclic oligonucleotides can induce hairpinlike structures in linear DNA fragments. By using NMR and CD spectroscopy we have studied the interaction of the cyclic oligonucleotide d with d, as well as with its two linear analogs d(GTCCCTCA) and d(CTCAGTCC). Here we report the NMR structural study of these complexes. Recognition between these oligonucleotides occurs through formation of four intermolecular Watson-Crick base pairs. The three-dimensional structure is stabilized by two tetrads, formed by facing the minor-groove side of the Watson-Crick base pairs. Overall, the structure is similar to those observed previously in other quadruplexes formed by minor-groove alignment of Watson-Crick base pairs. However, in this case the complexes are heterodimeric and are formed by two different tetrads (G:C:A:T and G:C:G:C). These complexes represent a new model of DNA recognition by small cyclic oligonucleotides, increasing the number of potential applications of these interesting molecules. 相似文献
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