SERS标记的金纳米棒探针用于免疫检测

报道了基于金纳米棒表面增强拉曼散射(SERS)的免疫检测. 将拉曼活性分子对巯基苯甲酸吸附于金纳米棒表面, 制备出SERS标记的金纳米棒探针. 该探针和蛋白抗体结合形成SERS标记抗体. 通过SERS标记抗体、待测抗原和俘获抗体(固体基底上修饰的抗体, 即俘获抗体)之间的免疫应答反应, 将金纳米棒探针组装到固体基底上, 形成SERS标记抗体-抗原-俘获抗体 “三明治”夹心复合体. 待测抗原浓度越大, 固体基底上俘获的金纳米棒探针的数目越多, 从而可通过SERS信号的强弱来检测待测抗原的浓度. 由于金纳米棒的表面等离子体共振(SPR)峰位置可以在较宽的范围内调控, 可通过激发光和SPR的耦合来提高SERS信号, 从而提高免疫检测的灵敏度. 单组分抗原可检出的浓度范围高于1×10－8 mg/mL.     

纳米金增强SPR检测产毒赭曲霉中PKS基因的特异性碱基

基于双通道表面等离子体子共振(surface plasmon resonance,SPR)传感器,分别采用直接法和金纳米粒子作为传感层的方法,通过检测赭曲霉毒素A(ochratoxin A,OTA)合成初期阶段表达的聚酮合成酶(polyketide synthase,PKS)基因的25个特异性碱基的寡核苷酸链,建立了一种高灵敏、间接检测OTA的新方法.同时考察了6-巯基己醇(6-mercapto-1-hexanol,MCH)作为封闭液对SPR响应信号的影响.结果表明,直接法的检测限为12.5 nmol/L,MCH的加入可使响应信号有所增强,使用金纳米粒子作为传感层的检测下限为0.25 nmol/L,与直接法相比较灵敏度提高了50倍,与以往使用金纳米粒子标记抗体或抗原相比,其作为传感层也能大大提高SPR检测灵敏度,且操作简单易行.     

基于纳米抗体-碱性磷酸酶融合蛋白的一步酶联免疫吸附分析法检测黄曲霉毒素B1

从噬菌体展示的抗黄曲霉毒素B1(AFB1)纳米抗体文库中,通过四轮亲和淘选,得到抗AFB1纳米抗体G8.将编码纳米抗体G8的基因与碱性磷酸酶(AP)基因融合,构建了重组融合表达载体pET25b(+)-G8-AP,将其转化大肠杆菌BL21(Rosetta,DE3)感受态细胞,异丙基-β-D-硫代吡喃半乳糖苷(IPTG)诱导融合基因表达.SDS-PAGE结果表明,融合蛋白G8-AP为可溶性表达,Ni2+-NTA亲和层析柱纯化融合蛋白,对硝基苯磷酸二钠(pNPP)法测得纯化后的G8-AP的碱性磷酸酶比活力为(364.5±8.3)U/mg.ELISA检测结果表明,G8-AP具有特异识别AFB1的活性,与其它真菌毒素(AFB2、AFG1、AFG2、脱氧雪腐镰刀菌烯醇、玉米赤霉烯酮、伏马菌素B1)无交叉反应.基于G8-AP建立了检测AFB1的一步ELISA法.在优化的条件下,即甲醇浓度20％、盐离子浓度20 mmol/L、pH 7.4条件下,方法的半数抑制浓度(IC50)为19.8 ng/mL,线性范围为4.3 ～ 92 ng/mL,检出限为2.6 ng/mL.对玉米和小麦样品加标回收实验结果表明,基质对本方法的干扰不明显,可用于实际样品检测.     

纳米孔技术对PD-1抗原抗体结合检测的实验研究

肿瘤的免疫疗法是利用人体自身的免疫系统去治疗肿瘤的一种方法，程序性死亡受体1（PD-1）是肿瘤免疫疗法中的一种免疫检查点，利用PD-1或PD-L1的单克隆抗体，可以阻断PD-1/PD-L1信号通路，恢复T细胞的免疫杀伤功能，实现肿瘤的免疫治疗.为了研究PD-1抗体药物与人体PD-1抗原的结合有效性，以PD-1蛋白质分子为实验对象，用纳米孔传感器件开展了PD-1、PD-1抗体及其结合物的辨识.分别对纯PD-1蛋白质分子和其抗体分子进行了纳米孔过孔实验研究，发现PD-1及其抗体的相对堵塞电流幅值比分别为0.00404和0.01297，实现了抗原抗体分子的区分.并对Si₃N₄纳米孔内壁进行了PD-1抗体修饰，再将PD-1蛋白质分子通过经抗体修饰后的纳米孔，以期实现结合物的检测，实验结果显示部分抗原抗体实现了特异性结合，剩下部分呈游离状，所以纳米孔技术可实现抗原抗体结合物的区分.未来，纳米孔有望成为无标志检测药物有效性的一种新手段.     

抗体和寡核苷酸双标记纳米金生物探针的制备及生物学特性

纳米金通过静电吸附抗体, 与寡核苷酸共价结合制备双标记纳米金生物探针, 比较了双标记纳米金生物探针和单标记抗体IgG或ss-DNA的稳定性和反应性. 结果表明, 在水溶液中纳米金由于ss-DNA的结合使IgG抗体的吸附能力明显改善, IgG的吸附也影响二硫苏糖醇(DDT)对ss-DNA的解离作用. 双标记纳米粒上覆盖(50±15)条ss-DNA和(10±2)条IgG, 较单标记ss-DNA纳米金上的(70±15)条要少. 斑点免疫和杂交实验证明, 纳米金表面标记的IgG和ss-DNA具有良好生物学活性. 双标记纳米金生物探针在超微量蛋白质的检测中具有应用价值.     

金纳米粒子与抗体蛋白相互作用的光谱研究

本文运用透射电镜(TEM)、Zeta电位测量、紫外-可见吸收光谱(UV-Vis)、荧光光谱以及衰减全反射傅立叶变换红外光谱(ATR-FTIR)等技术手段,研究了免疫球蛋白G(IgG)与金纳米粒子的相互作用。结果表明,所制备的金纳米粒子呈均一分散的球形,抗体蛋白能够与金纳米粒子形成稳定的复合物。内源荧光光谱表明金纳米粒子对抗体蛋白的内源荧光有显著的静态猝灭,猝灭常数KSV=4.25×109 L·mol-1,同时金纳米粒子与抗体蛋白间有较强的作用,结合常数K=1.95×1014,结合位点数n为1.49。外源荧光光谱表明金纳米粒子与抗体蛋白之间的作用力主要是疏水相互作用。ATR-FTIR分析抗体蛋白与金纳米粒子作用前后蛋白二级结构的变化,结果显示,抗体蛋白有序结构含量降低,构象朝着更加松散的状态变化。     

用于输送siRNA的聚乙烯亚胺-聚乙二醇二丙烯酸酯纳米凝胶

阐述了一种新的用于输送小干扰核糖核酸(siRNA)的聚乙烯亚胺-聚乙二醇二丙烯酸酯纳米凝胶的合成及其表征.在反相微乳液体系中,聚乙烯亚胺(PEI)和聚乙二醇二丙烯酸酯(PEG-DA)通过麦克尔加成交联得到纳米凝胶.1H-NMR和FTIR的结果充分证明纳米凝胶的化学结构,而动态光散射则表明纳米凝胶的颗粒粒径均匀,约为180 nm,zeta电位为37.9 mV.同时,MTT结果表明纳米凝胶在高达1 mg/mL的浓度下对MCF-7细胞也基本没有毒性.凝胶阻滞实验证明纳米凝胶在体外可以通过静电相互作用稳定结合siRNA.转染实验结果表明纳米凝胶与GFP siRNA的复合物能降低MCF-7 KMRV细胞(一种能稳定表达GFP蛋白的MCF-7细胞系)GFP蛋白的表达.以上结果证明这种生物相容性的纳米凝胶可以结合并输送siRNA进入细胞,沉默相关基因的表达.     

Fe3O4/葡聚糖/抗体磁性纳米生物探针的制备和层析检测

在免疫检测中 ,经常利用一些具有特殊物理化学性质的标记物对抗体 (或抗原 )进行偶联标记 ,在抗体与抗原识别后 ,通过对标记物的定性和定量检测而达到对抗原 (或抗体 )检测的目的 .传统的免疫标记物包括放射性同位素 [1] 、酶 [2 ] 、胶体金 [3] 和有机荧光染料分子 [4 ] 等 .近年来 ,随着纳米技术的发展 ,半导体荧光纳米晶 [5,6 ] 和磁性纳米晶 [7] 在免疫检测方面受到了广泛关注 .磁性纳米晶性能稳定 ,较易制备 ,可与多种分子复合使粒子表面功能化 ,并且由于磁纳米晶具有超顺磁性 ,为样品的分离、富集和提纯提供了很大方便 .这些优点使它…     

基于纳米金复合探针-蛋白芯片检测心肌损伤标志物

运用纳米金复合探针结合蛋白芯片,建立了一种检测心肌损伤标志物的新方法.构建了2种纳米金探针:标记有检测抗体和DNA探针1的检测探针和标记有DNA探针2(与DNA探针1的碱基互补配对)的信号探针.当目的抗原存在时,检测探针经检测抗体和抗原,与芯片上捕获抗体结合固定在芯片上,信号探针通过碱基互补配对与检测探针结合使信号放大,最后利用纳米金成核原理染色,通过显微镜观察结果并定量分析.该体系在40 min内可检测多种标志物,其中肌钙蛋白Ⅰ(c TnⅠ)的检出限为10 pg/m L,与临床电化学发光法(ECLIA)灵敏度相当;肌红蛋白(MYO)与新型脂肪酸结合蛋白(HFABP)的检出限分别为640和10 pg/m L,与ECLIA及酶联免疫吸附法(ELISA)相比,灵敏度显著提高.     

基于褐藻酸钠-纳米金复合物作非酶标记的新型电化学免疫传感器的研制

比较了用三碘甲状腺氨酸抗体(T3抗体)、褐藻酸钠(AS)标记T3抗体及褐藻酸钠-纳米金复合物(ASN)标记的T3抗体,在通过免疫反应结合到免疫电极表面后,引起的电极表面微环境发生改变的程度;用Fe(CN)3-/4-6为电化学探针,用循环伏安法获取金电极表面微环境改变的电流信息来检测 T3抗体,检测的线性范围为100～1 600ng·ml-1,检出限为45ng·ml-1.     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

Summary of development of the theory of stability of colloids and thin films

In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。     

Thermodynamics of the formation of oxosulfides of rare-earth elements

The enthalpies of solution of several oxosulfides of rare-earth elements and the high-temperature enthalpies of oxosulfides and oxosulfates of lanthanum and yttrium were measured using solution calorimetry and high-temperature microcalorimetry techniques. Standard enthalpies of formation and some thermodynamic properties of oxosulfides and oxosulfates were calculated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2 pp. 294–297, February, 1997.     

探究“铁的锈蚀条件”实验创新设计

设计了铁的锈蚀实验,说明了铁钉的处理方法,增加了温度、酸、碱的影响条件,实现了铁跟蒸馏水及空气中氧气快速反应而生锈,使实验在5 min左右就能够得到准确的结果。