盐酸平阳霉素与核酸相互作用的共振Rayleigh散射光谱及其分析应用

用共振Rayleigh散射(Resonance Rayleigh scattering, RRS)光谱结合吸收光谱和荧光光谱研究了盐酸平阳霉素(BleomycinA₅, BLMA₅)与核酸的相互作用. 在pH 2.2左右的酸性介质中, BLMA5能够与核酸结合形成复合物, 引起RRS显著增强, 并产生新的RRS光谱, 具有特征吸收波长红移和分子吸收增色效应, 能观察到BLMA₅的荧光猝灭. 不同核酸的RRS光谱特征略有差异, 最大散射波长分别位于301 nm(ctDNA和sDNA), 370 nm(hsDNA)和310 nm(RNAtypeⅢ和RNAtypeⅥ), 散射增强的程度各不相同, 其中DNA的增强程度比RNA大. 讨论了BLMA₅和核酸反应的最佳反应条件及影响因素, 并对BLMA5与核酸的结合模式、反应机理进行了讨论. 建立了一种以BLMA₅为探针用RRS法测定DNA的高灵敏度、简单、快捷的分析方法. 该方法的检出限(3σ )分别为5.7 ng·mL^-1(ctDNA), 7.4 ng·mL^-1 (sDNA), 9.2 ng·mL^-1 (hsDNA), 能用于痕量DNA的测定.     

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。     

铁纳米粒子共振光散射测定纳克级核酸

核酸作为生物遗传的物质基础,对其进行分析化学研究一直备受关注.当前,微流控分析技术的快速发展为核酸的高灵敏检测展示了新的前景.     

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...     

甲基紫6B与核酸作用的共振光散射光谱及其分析应用

将三苯甲烷类碱性染料甲基紫6B用于核酸的共振光散射测定。在pH10.8的缓冲液中 ,核酸的加入导致甲基紫6B在386nm处共振光散射的增强 ,其强度与核酸的质量浓度呈线性关系 ,据此建立了一种测定核酸的共振光散射法。fsDNA与 yRNA的线性范围分别为0.083～1.0mg·L -1和0.076～0.8mg·L -1,检出限分别为82.6和75.3μg·L -1。将该法用于混合样品中核酸的测定 ,结果令人满意。     

用四氨基铝酞菁共振光散射技术测定纳克级核酸

痕量核酸对四氨基铝酞菁的共振散射光产生增强作用,且增强程度与核酸浓度之间有良好的线性关系.据此建立了测定核酸的高灵敏共振散射光增强分析方法.在pH=6.0、最大散射波长400nm处,测定小牛胸腺DNA(CTDNA)、鲑鱼精子DNA(SMDNA)和酵母RNA(YeastRNA)的线性范围分别是0～250ng/mL,0～200ng/mL和0～400ng/mL,检测限分别为1.4ng/mL,1.4ng/mL和2.7ng/mL.该法简单,灵敏度高,用于实际样品中核酸含量的测定,所得结果与紫外吸收法一致.     

氯金酸-罗丹明S缔合纳米微粒体系的共振散射增强与荧光猝灭研究

在0．2mol/L HCl介质中，罗丹明S(RDS)分别在520nm和550nm处有一个吸收峰和荧光峰。当有Au(Ⅲ）存在时，Au（Ⅲ）与Cl^-形成AuCl4^-，AuCl^-与RDS^ 借助于静电引力形成疏水性的AuCl4-RDS缔合物分子。AuCl4-RDS分子间存在较强的分子间作用力和疏水作用力而生成(AuCl4-RDS)。缔合纳米微粒，粒径为45nm。在360nm产生瑞利散射峰，在600nm产生共振散射峰。由于纳米微粒形成后，只有裹露在(AuCl4-RDS)n纳米微粒界面的RDS荧光分子才能吸收激发光子跃迁到激发态，进而返回基态产生荧光。而体相的RDS荧光分子无法与激发光作用产生荧光，即受激RDS分子数大为降低，故550nm荧光峰和520nm吸收峰的降低。当缔合纳米微粒体系加入乙醇后，体系的红紫色和共振散射峰消失，吸收峰和荧光峰恢复，由于乙醇致使(AuCl4-RDS)。纳米微粒分解为AuCl4-RDS分子。结果表明：红紫色(AuCl4-RDS)n纳米粒子的形成是其共振散射增强、荧光猝灭和产生共振散射峰的根本原因。     

丙三醇对水溶液中血红蛋白构象的影响——荧光猝灭和动态光散射研究

利用荧光猝灭法和动态光散射法测定丙三醇-水混合溶剂中血红蛋白(Hb)与联苯胺的结合距离和Hb的流体动力学半径, 并通过分析Hb荧光光谱和吸收光谱的变化, 探讨丙三醇与蛋白质分子在水溶液中相互作用的机理及其对蛋白质构象的影响. 结果表明, 丙三醇-水混合溶剂中Hb通过优先水化作用形成更紧密的构象, 溶剂体系的氢键形成能力下降对稳定蛋白质的构象有重要的影响, 丙三醇浓度较高的混合溶剂中氢键网络发生崩塌, 导致蛋白质构象产生进一步的折叠. 实验显示, 尽管Hb在丙三醇-水混合溶剂中保持较完整的血红素疏水空穴结构, 但是血红素疏水空穴以外肽段的构象发生显著变化, 并对血红蛋白的聚集状态造成一定的影响.     

共振光散射技术的原理及其在生化研究和分析中的应用

共振光散射技术是一项在普通荧光分光光度法计上进行测量的光散射分析技术。本文在简要介绍该技术的基础上，作了可能的原理的探索和定量基础讨论，就共振光散射技术在有机染料分子的聚集、在生物大分子上的堆积以及对生物大分子构象所产生的影响方面作了综述，简要评价该技术在生物大分子分析中的应用，并对其在生化研究和分析中可能的发展进行了预测。     

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％。     

Determination of Nucleic Acids Based on their Resonance Light Scattering Enhancement Effect on Metalloporphyrin Derivatives

A new method for the determination of nucleic acids at nanogram per mL level is proposed based on the enhanced resonance light scattering (RLS) signal resulting from the interaction of metalloporphyrins with nucleic acids. Under optimum conditions, the weak RLS signal of metalloporphyrin is enhanced by nucleic acids, and the enhanced RLS intensity is proportional to the concentration of nucleic acids. The detection limits of calf thymus DNA were 3.5ngmL^–1, 2.9ngmL^–1 and 1.0ngmL^–1 for three metalloporphyrins, respectively. Synthetic samples were determined with satisfactory results.     

Resonance Double Light Scattering Method for the Determination of Nucleic Acids with Cetylpyridine Bromide

Cetylpyridine bromide (CPB) was used as a novel probe to determine nucleic acids by the resonance double light scattering technique in this paper. Under the optimum conditions, different nucleic acids have different binding properties with CPB. The sensitivity of this method decreases in the following order: ctDNA>yRNA>fsDNA. The detection limits are 8.9, 12.7 and 18.7ngmL^–1, respectively. Synthetic samples were analyzed satisfactorily.     

Application of L-Cysteine-Capped ZnS Nanoparticles in the Determination of Nucleic Acids Using the Resonance Light Scattering Method

Nanometer-sized L-cysteine-capped ZnS particles were synthesized by a colloidal aqueous method. The functionalized nanoparticles are water-soluble and suitable for biological applications. In Tris-HCl buffer solution, nucleic acids combine with cysteine-capped nano-ZnS particles by intermolecular forces to form larger nanoparticles. There are two resonance light scattering peaks at 304.5nm and 373.8nm, respectively. The enhanced RLS is related to the concentration of nucleic acids in the range of 0.04 to 1.2µgmL^–1 for calf thymus DNA and 0.2 to 1.0µgmL^–1 for fish sperm DNA. The detection limits (3) are 19ngmL^–1 for calf thymus DNA and 23ngmL^–1 for fish sperm DNA, respectively. Four synthetic samples were analyzed satisfactorily.     

Resonance Light Scattering Spectra of Silver Thiocyanate System and its Application in Analysis

A novel determination method of Ag^＋ was established. In acetic acid-sodium acetate buffer （pH 5.0） medium, Ag^＋ reacts with SCN^- to form AgSCN in the presence of TritonX-100,which results in an increase of resonance light scattering （RLS）and giving a new RLS spectrum.The maximum RLS peak was at 585 nm,The enhancement of resonance light scattering at 585 nm was proportional to the concentration of Ag^＋ ranging from 0.0045-4.00μg mL^-1 （r=9991）,and the detection limit was 1.37 ng mL^-1 with the recovery of 97.70%- 104.80%。     

邻苯二酚紫-溴化十六烷基三甲铵-核酸共振光散射体系的研究及其分析应用

研究了核酸与阴离子染料邻苯二酚紫(PV)及阳离子表面活性剂溴化十六烷基三甲铵(CTMAB)体系的共振光散射光谱特性。在pH2．35的柠檬酸介质中，核酸(yRNA或fsDNA)与阳离子表面活性剂CTMAB对邻苯二酚紫的共振光散射光谱有协同增强作用，产生最大散射波长为400nm的共振光散射光信号。在最佳实验条件下，共振光散射测定yRNA和fsDNA的线性范围皆为0．02-0.75mg／L，检出限分别为1．4和8．7μg/L。据此建立了一种测定核酸的新方法。     

Interactions of Night Blue with Nucleic Acids and Determination of Nucleic Acids Using Resonance Light Scattering Technique

The noncovalent interactions of night blue (NB) with several nucleic acids in buffer medium of Britton‐Robinson at pH 4.1 have been studied by spectroscopic methods. It is shown that the binding of NB with nucleic acids involves the J‐aggregation of NB molecules on the surface of nucleic acids. The aggregation was encouraged by polyanions nucleic acids, in which nucleic acids served for acting templates. In this connection, a new method of nucleic acids with sensitivity at nanogram level is proposed based on the measurement of enhanced resonance light scattering (RLS). The linear range of ctDNA, fsDNA and yRNA is 0.01—2.5, 0.03—2.5 and 0.04—1.0 μg/mL, respectively, and the corresponding detection limits (3s?) are 9.4, 7.3 and 5.7 ng/mL at 2.5 × 10–⁵mol/L of NB. Synthetic and real samples were analyzed with satisfactory results.     

A High-Sensitivity Assay of Nucleic Acids with Tetraphenyl Porphyrin Cobalt Chlorine by Resonance Light Scattering Technique

Abstract

A novel probe, tetraphenyl porphyrin cobalt chlorine (CoTPPCl), is first applied to determine nucleic acids at the nanogram level based on the measurement of resonance light scattering (RLS) signals, which result from the interaction of CoTPPCl with nucleic acids. Under pH 6.37 conditions, the reaction between CoTPPCl and nucleic acid enhances the weak resonance light scattering (RLS) signal of CoTPPCl, and the enhanced light scattering intensity is proportional to the concentration of nucleic acid. The method is sensitive (3.45 ng/mL for ctDNA), simple (one step and a common fluorimeter), and tolerant of the metal ions and other coexistent substances. The mode of the combination between CoTPPCl and nucleic acids and the reasons for RLS enhancement are clearly clarified. Synthetic samples were determined with satisfactory results.     

阿特拉津与DNA作用共振光散射光谱的研究及其应用

首次报道了阿特拉津与ctDNA作用的共振光散射光谱 (RLS)特征和利用小分子农药阿特拉津作为探针测定痕量脱氧核糖核酸的方法。在 pH=1.41的酸度条件下 ,阿特拉津 -ctDNA在319.8nm处有一增强的共振光散射光谱峰 ,且增强的共振光散射强度与ctDNA的浓度成线性关系。在实验确定的优化条件下 ,方法的线性范围为0.05～34μg·mL -1 ,检出限为11.9ng·mL -1(3δ) ,该方法成功地用于人工混合样品中ctDNA的测定     

苋菜红—蛋白质体系的共振光散射光谱研究及其分析应用

研究了染色剂苋菜红与蛋白质的结合反应,在ＰＨ３．８７的Ｃｌａｒｋ－Ｌｕｂｓ缓冲介质中,苋菜红与蛋白质通过分子间作用力形成复合物。使最大波长约为３６４ｎｍ的共振光散射光谱得到加强。以苋菜红为标记物根据其共振光散射的增强程度。可用于蛋白质的定量测定,其线性响应范围为０－５．０ｍｇ／Ｌ。方法的稳定性及选择性良好,用于人血清试样中总蛋白的测定,结果与经典的考马斯亮兰法一致。