Resonance light scattering spectroscopy study of interaction between gold colloid and thiamazole and its analytical application

In this paper, we used resonance light scattering (RLS) spectroscopy to study the interaction between thiol-containing pharmaceutical-thiamazole and gold colloid. At pH 5.2, the resonance light scattering spectrum of gold nanoparticles has a maximum peak at 555 nm and the RLS intensity is enhanced by trace amount of thiamazole due to the interaction between thiamazole and gold colloid. The binding of colloidal gold to thiamazole results in ligand-induced aggregation of colloidal gold, which was characterized by RLS spectrum, ultraviolet-visible (UV-Vis) spectrum, and transmission electron microscopy (TEM). Based upon the study, we proposed a highly sensitive, gold colloid-based assay using RLS spectrum to detect pharmaceuticals for the first time. The mechanism of binding interaction between Au colloid and thiamazole was also discussed.     

金纳米微粒共振光散射光谱探针测定维生素B_4-水溶性腺嘌呤的研究

建立了一种以金纳米微粒为探针共振光散射(RLS)法测定维生素B4的新方法.在弱酸性介质中(pH 4.2),金纳米微粒在635 nm有一最大共振散射峰.加入微量维生素B4后,金纳米微粒与维生素B4通过静电引力结合.形成了粒径较大的聚集体,导致RLS强度显著增强.研究了体系的共振光散射光谱特征和反应适宜条件,探讨了共振光散射增强的机理.结果表明,维生素B4质量浓度在0.1～5.0μg/mL 时与散射强度(△I)呈线性关系,检出限(3σ)为12.0 ng/mL,相对标准偏差(RSD)为2.2%.该方法已用于片剂中维生素B4的测定.     

Resonance light scattering spectroscopy study of interaction between norfloxacin and calf thymus DNA and its analytical application

The interaction between norfloxacin and calf thymus double-stranded DNA (dsDNA) has been studied by a resonance light scattering (RLS) technique with a common spectrofluorometer. The characteristics of RLS spectra, the effective factors and optimum conditions of the reaction have been investigated. In Britton-Robinson (BR) buffer (pH 5.87), norfloxacin has a maximum peak 405.5 nm and the RLS intensity is remarkably enhanced by trace amount of calf thymus dsDNA due to the interaction between norfloxacin and dsDNA. The binding of norfloxacin to DNA forms large particles, which were characterized by RLS spectrum, scanning electron microscopy (SEM), ultraviolet-visible (UV-vis) spectrum, and fluorescence spectrum. Based on the enhanced RLS intensity, a novel method for sensitive determination of calf thymus dsDNA concentration ranging from 0.02 to 2.3 microg ml(-1) was developed. The determination limit (3 sigma) was 1.2 ng ml(-1). The method is simple, rapid, practical and relatively free from interference generated by coexisting substance, as well as much more sensitive than most of the reported methods. Three synthetic samples of ctDNA were determined with satisfactory results.     

V(Ⅴ)-I~--十六烷基三甲基溴化铵体系共振散射光谱及分析应用

研究了在盐酸介质中,V(Ⅴ)-I--十六烷基三甲基溴化铵(CTMAB)离子缔合物的共振散射光谱。实验发现,当有V(Ⅴ)存在时,V(Ⅴ)与过量的I-反应生成I3-,I3-与CTMAB形成离子缔合物微粒(CTMAB+.I3-)n,使I--CTMAB溶液的共振光散射强度显著增加。在波长563nm处,共振散射光强度最大且光散射强度与钒浓度在2～60ng/mL范围内呈正比,据此建立了测定环境样品中痕量钒的共振散射光谱分析新方法,方法检出限为0.66ng/mL。用拟定的方法测定环境样品中微量钒,相对标准偏差小于7.5%,回收率在97.8%～102.4%。     

Phase separation in polystyrene/poly (vinyl methyl ether) blend revealed by two-dimensional correlation resonance light scattering spectroscopy

Two-dimensional (2D) correlation resonance light scattering (RLS) spectroscopy has been successfully applied to investigate phase separation of polystyrene (PS)/poly (vinyl methyl ether) (PVME) film by using a conventional spectrofluorimeter. 2D synchronous correlation RLS spectrum indicates that the RLS peak intensity drastically increases with a rise in temperature due to aggregation of chromophores (i.e. phenyl rings) in PS particles in the course of phase separation. In addition, as concluded by 2D asynchronous correlation RLS spectrum, RLS has higher sensitivity than conventional light scattering. For RLS, the closer to the absorption band, the more sensitive it is to the aggregation during phase separation. By means of moving-window two-dimensional (MW2D) correlation spectrum based on autocorrelation calculations, the cloud point (370 K) was determined, which is in good agreement with the literature. On the other hand, time evolution of RLS intensity at various temperatures distinctly shows that phase separation of PS/PVME film involves two mechanisms, i.e. spinodal decomposition (SD) and nucleation and growth (NG). Accordingly, 2D correlation RLS proves to be a very simple and sensitive method to monitor phase separation in polymer blends and might supplement the existing characterization tools.     

Study on naringenin-CTMAB-DNA system by resonance light scattering technique and its analytical application

A new high-sensitivity determination method of deoxyribonucleic acid (DNA) with detection limit at nanogram levels was proposed. Based on the measurement of resonance light scattering (RLS), it was found DNA could combine with naringenin and cetyltrimethylammonium bromide (CTMAB) in basic Tris-HCl buffer and produce enhanced RLS signal. The optimum conditions for this system were studied in detail. The enhanced intensity of RLS of naringenin-CTMAB at 353 nm was directly proportional to the concentration of DNA in the range of 0.017-1.7 μg mL(-1). The detection limit was 5.06 ng mL(-1). Using the proposed method, the synthetic samples were analyzed with satisfactory results, the recovery was 99.3-105.0% and RSD was 0.7-3.7%.     

共振光散射方法研究钙存在下十二烷基苯磺酸钠的聚集行为

利用共振光散射技术在不引入探针的条件下,建立了室温下直接测定十二烷基苯磺酸钠(SDBS)的临界胶束浓度(CMC)的方法.研究发现:在室温下,SDBS水溶液的共振光散射强度(RLS)随SDBS浓度的增加而增强;且当SDBS接近其临界胶束浓度时,RLS强度增强显著,共振光散射峰分别位于330和396 nm.396 nm处的RLS强度与SDBS浓度关系曲线呈S型曲线,本文将曲线突升起点处两条切线的交点对应的SDBS浓度,确定为SDBS的临界胶束浓度(CMC),这与荧光芘探针和电导率等方法测定结果基本一致.并利用此方法分别研究了Ca2+浓度对SDBS及其SDBS-聚乙二醇辛基苯基醚(OP)复配体系聚集行为的影响.结果表明,SDBS与OP以1∶ 3复配时,增强了体系的抗钙能力.     

Resonance light scattering of 1-hydroxypyrene-ethyl violet-anionic surfactant system and its analytical application.

A novel method for the rapid and sensitive analysis of 1-hydroxypyrene (1-OHP) in human urine has been developed that uses a resonance light scattering (RLS) technique. The assay was based on the interaction of ethyl violet (EV) with 1-hydroxypyrene to form an ion-associate complex, which resulted in the enhancement of RLS intensity and the appearance of new RLS spectra. In the presence of anionic surfactant, the maximum RLS peak of the system was located at 396 nm at pH 8.0. Under the optimum conditions, it was found that the enhanced RLS intensity was directly proportional to the concentration of 1-hydroxypyrene in the range of 4.0 - 982 microg l(-1). The detection limit was 1.2 microg l(-1) and the recoveries of 1-hydroxypyrene were 92.8 - 102.3% (n = 6). The proposed method was successfully applied to the analysis of human urine samples. The results of 1-hydroxypyrene were in agreement with those obtained by the method of high-performance liquid chromatography.     

聚丙烯酸与核酸相互作用的共振光散射光谱研究及其分析应用

研究了聚丙烯酸(PAA)与脱氧核糖核酸(DNA)相互作用的共振光散射(RLS)光谱.实验结果表明,在pH=2.0的B-R缓冲溶液中,PAA与DNA自身的共振光散射峰均较弱,但当二者发生静电作用形成复合物后,体系的共振光散射峰增强,散射增强程度则各不相同,其相对散射强度的顺序是fsDNA＞ctDNA＞yRNA.在一定范围...     

Resonant-Mie-scattering of aggregates of phosphomolybdate and papaverine for measuring activities and screening inhibitors of cyclic nucleotide phosphodiesterase isozymes

A resonant-light-scattering (RLS) method was proposed to quantify phosphate for screening inhibitors of isozymes of cyclic nucleotide phosphodiesterase (PDE). In acidified mixtures of phosphate, papaverine and molybdate, there were aggregates exhibiting micrometre sizes, no absorbance peaks over 360 nm but strong RLS peaks at 392 nm; Mie scattering thus accounted for the RLS signals. When papaverine was added before molybdate to acidified samples of phosphate, RLS signals at 392 nm were stable from 5 to 25 min since the addition of molybdate; after optimization, phosphate from 0.40 to 3.60 μM was quantifiable. This RLS method tolerated 60 mg L⁻¹ proteins besides common PDE inhibitors and dimethyl sulfoxide in acidified samples of phosphate; the integration of this RLS method with the coupled action of a phosphomonoesterase on PDE product was thus rational to measure PDE activities without the removal of proteins in samples. By quantifying activities of a truncated mutant of human PDE4B2 via this RLS method, Michaelis–Menten constant, inhibition constants of rolipram, papaverine and theophylline varied over three magnitudes and were consistent with those estimated by an improved malachite green assay of phosphate, respectively. Hence, this novel RLS method was promising for screening inhibitors of PDE isozymes.     

A new way to detect the interaction of DNA and anticancer drugs based on the decreased resonance light scattering signal and its potential application

A novel assay has been developed to detect the interaction of DNA and anticancer drugs based on the decreased resonance light scattering (RLS) technique. The proposed method can be used to study those drugs which do not produce a RLS-signal after binding to DNA. RLS was used to monitor the interaction of five anticancer drugs with DNA. The reaction between anticancer drugs and DNA took place in BR buffer solution. From the RLS assay, the sequence of five anticancer drugs activities was as follows: CTX < MTX < Pt < MMC < 5-Fu. Mammary cancer cell DNA (mcDNA) was involved to validate the RLS assay. The results showed that the sensitivities of the five anticancer drugs targeting both mcDNA and ctDNA increased in the same order. However the sensitivity of each drug to mcDNA was higher than that to ctDNA It is a significant innovation of the RLS method to detect the interaction of DNA and anticancer drugs and to obtain drug sensitivity, which provides new strategies to screen DNA targeted anticancer drugs.     

A study on photochemical behavior of lysozyme-bromophenol blue complex and its analytical application

It was found that macromolecular complexes were formed between lysozyme and bromophenol blue (BPB) with the electrostatic attraction in acetate medium (pH 6.5). The binding constant and the number of binding site for lysozyme-BPB complex were obtained, and the thermodynamic parameters were given. In addition, a remarkable enhancement of resonance light scattering (RLS) intensity for the macromolecular complex was observed with a scattering peak at 336 nm. And the increment of RLS intensity was proportional to the concentration of lysozyme in the range of 5 ng ml(-1) to 10.0 microg ml(-1). The influence of experimental conditions including pH, BPB concentration, and ionic strength on RLS system were tested, especially the effect of temperature was examined in detail. The proposed method was successfully applied to determine lysozyme in human saliva and tear samples without any special pretreatment. Compared with other methods the proposed method is of higher sensitivity and wider linear range.     

共振瑞利散射法对普萘洛尔特效适配体系的手性分析

本文提出了对于手性药物普萘洛尔手性识别和手性分析的新方法。 该方法引用基于氧化石墨烯的指数富集配体系统进化筛选技术(GO-SELEX),经过10轮优化筛选出对心血管药物普萘洛尔有高度亲和力的特效适配体。 然后通过共振瑞利散射光谱法(RRS)对反应体系进行特效性检测,实验表明S-普萘洛尔和R-普萘洛尔有迥然不同的光谱差异,S-普萘洛尔与特效适配体结合后的RRS显著增强,而R-普萘洛尔与适配体结合后的RRS几乎没有变化。 据此可以对心血管药物手性普萘洛尔进行有效的手性识别。 在考察反应体系和实验条件的基础上,可对S-普萘洛尔进行实验检测,同时对外消旋体中的R-普萘洛尔进行计算分析。 实验对S-普萘洛尔的线性范围为5~275 nmol/L,检测限为0.5 nmol/L。 方法应用于外消旋药片的分析检测,结果令人满意。 实验表明,RRS检测特效适配体结合的手性靶标体系会彰显不同的光谱差异,从而可对手性对映体进行手性识别,尤其是可利用其光谱差异实现同时测定的手性分析,方法可在特殊情形下不经分离而同时测定手性对映体,具有推广应用价值。     

Determination of a cationic surfactant with naphthalene black 12B by the resonance light scattering technique

A new determination method for a cationic surfactant, zephiramine (Zeph), was developed with resonance light scattering (RLS) technique, based on the interaction of naphthalene black 12B with Zeph. The resonance light scattering (RLS) and UV characteristics of interaction between naphthalene black 12B and Zeph were studied. The RLS intensity of naphthalene black 12B at 363 nm was greatly enhanced in the presence of Zeph at pH 6.0. The enhanced RLS is proportional to the concentration of Zeph in the range of 3.20 x 10(-7) - 1.44 x 10(-5) mol L(-1). The limit of detection was 8.8 x 10(-8) mol L(-1). The proposed method was applied to the determination of Zeph in synthetic and spiked water samples with the recovery of 96.2-104% and RSD of 1.1-2.5%.     

A novel method for quantitative determination of tea polysaccharide by resonance light scattering

A new method for the determination of tea polysaccharide (TPS) in green tea (Camellia sinensis) leaves has been developed. The method was based on the enhancement of resonance light scattering (RLS) of TPS in the presence of cetylpyridinium chloride (CPC)-NaOH system. Under the optimum conditions, the RLS intensity of CPC was greatly enhanced by adding TPS. The maximum peak of the enhanced RLS spectra was located at 484.02 nm. The enhanced RLS intensity was proportional to the concentration of TPS in the range of 2.0-20 μg/ml. It showed that the new method and phenol-sulfuric acid method give some equivalent results by measuring the standard compounds. The recoveries of the two methods were 96.39-103.7% (novel method) and 100.15-103.65% (phenol-sulfuric acid method), respectively. However, it showed that the two methods were different to some extent. The new method offered a limit of detection (LOD) of 0.047 μg/ml, whereas the phenol-sulfuric acid method gives a LOD of 1.54 μg/ml. Interfered experiment demonstrated that the new method had highly selectivity, and was more suitable for the determination of TPS than phenol-sulfuric method. Stability test showed that new method had good stability. Moreover, the proposed method owns the advantages of easy operation, rapidity and practicability, which suggested that the proposed method could be satisfactorily applied to the determination of TPS in green tea.     

A sensitive rutin assay using a simple probe manganese sulfate based on its novel resonance light scattering decrease phenomenon

A novel resonance light scattering (RLS) decrease method was developed to determine rutin with a simple probe manganese sulfate. At pH 7.5, the strong RLS intensity of manganese sulfate was remarkably decreased by the addition of rutin with the maximum peak located at 389.0 nm. Under the optimum conditions, a good linear relationship between the changes of RLS intensities of manganese sulfate with and without rutin and the concentrations of rutin was obtained over the range of 0.49-24.4 microg ml(-1) and a low detection limit (3sigma) 0.42 microg ml(-1) was achieved in the mean time. Based on this approach, a novel method for quantitative analysis of rutin is proposed in this paper. The method proposed was also applied successfully to the determination of rutin in commercial pharmaceutical preparations of compound rutin tablets and human urine samples. The assay is sensitive, rapid, inexpensive, practical and relatively free from interference generated by coexisting substances.     

瑞利光散射技术用于药物中盐酸米多君的测定

建立快速、准确、灵敏的检测药物中盐酸米多君的瑞利光散射(RLS)新方法。在pH 4.55 Tris-盐酸溶液和十六烷基溴化吡啶鎓溶液中,盐酸米多君与坚绿FCF 反应生成三元离子缔合物,使体系的RLS信号显著增强并产生具有2 个强散射峰的新RLS 光谱。在最大RLS 峰364 nm 处,盐酸米多君的质量浓度在0.004~0.35 mg·L^-1范围内与缔合物的RLS 增强强度(ΔIRLS)呈线性关系,检出限(3Sb/S)为0.0031 mg·L^-1。加标回收率和相对标准偏差(RSD)(n=5)分别为98.3%~102% 和1.0%~1.3%。该法用于药物中盐酸米多君含量的测定,结果满意。     

Determination of methylene blue by resonance light scattering method using silica nanoparticles as probe

A simple and novel method was developed to determine methylene blue(MB) by resonance light scattering(RLS) using silica nanoparticles(SiO_2NPs) as the probe.It was found that MB could enhance the RLS intensity of SiO_2NPs.Moreover,the increase in RLS intensity was linear with the concentration of MB over the range of 0.01-3.0 μg mL~(-1).The limit of detection(LOD) was as low as 4.36 ng mL~(-1)(3σ) and the relative standard deviation(RSD) was 2.4%(n=6).Under the optimum experimental conditions,this proposed method was successfully applied for the determination of MB in aquaculture samples with recoveries between 96.3% and 107%.Possible mechanisms for the RLS enhancement of SiO_2NPs in the presence of MB were also discussed.     

DNA对Ru(bpy)_2(dppx)~(2+)-SDS体系共振光散射的猝灭作用及其应用

研究了Ru(bpy)2(dppx)2+-SDS-DNA(bpy=2,2′-联吡啶,dppx=7,8-二甲基-吡啶并[3,2-a:2′,3′-c]吩嗪)体系的共振光散射光谱。结果表明,在阴离子表面活性剂十二烷基硫酸钠(SDS)预胶束聚集体存在下,Ru(bpy)2(dppx)2+-SDS体系具有很强的共振光散射,DNA的加入使其共振散射光猝灭。探讨了反应机理。基于DNA对Ru(bpy)2(dppx)2+-SDS体系共振光散射的猝灭作用,建立了共振光散射法测定DNA的新方法。在最佳实验条件下,体系在393nm处的共振光散射猝灭程度与DNA的浓度呈线性关系,线性范围为0.01～1.2mg/L,检出限为1.5μg/L。     

A resonance light scattering ratiometry applied for binding study of organic small molecules with biopolymer

Resonance light scattering (RLS) technique is a creative application of light scattering signals detected by using a common spectrofluorometer, but it has drawbacks such as the fluctuation of signals caused by poorly quantified or variable factors. Herein we develop a RLS ratiometry to overcome the drawbacks of the technique and apply to measure the binding nature of organic small molecules (OSM) with biopolymer using the binding of cation porphyrins with heparin (HP) as an example. In near neutral solution, cationic porphyrins meso-tetrakis [(trimethylammoniumyl) phenyl] porphyrin (TAPP) and meso-tetra (4-methylpyridy) porphyrin (TMPyP-4) interact with heparin, resulting in hypochromatic effect, and enhanced RLS signals. Linear relationship could be established between the ratio of enhanced RLS signals at two wavelengths, where the maximum and minimum are available in the ratio curve of UV-vis spectrum of porphyrin to that of heparin-porphyrin complex, and the logarithm of heparin concentration, and thus a wide dynamic range detection method of biopolymers could be developed. In comparison with RLS method, this RLS ratiometric one is less affected by environmental conditions such as pH, ionic strength. The mechanism of these interactions was investigated based on the charge density distribution of the two porphyrin molecules and it could be concluded that the enhanced RLS intensity is proportionally promoted by the charge capacity of components in the complex. Additionally, the binding number and binding constant were measured scientifically by Scatchard plot.