水溶性小金纳米簇SEC分离条件的建立

提出以纯水为流动相,在不外加任何辅助剂的条件下,用尺寸排阻色谱法(SEC)分离巯基丁二酸(MSA)单层包裹的粒径约1～5 nm的水溶性小金纳米簇.建立了其稳定的色谱条件.环境友好,操作简单,重现性好.     

羊毛角蛋白基金纳米团簇的制备及其打印成像的应用

利用羊毛角蛋白作为还原剂和稳定剂合成金纳米团簇溶液,通过可见光和紫外光的对比图像以及荧光光谱对pH值、反应温度和反应时间3个影响因素进行分析,确定金纳米团簇合成的最优方案。采用透射电子显微镜观察金纳米团簇的尺寸及分布,并将羊毛角蛋白基金纳米团簇用作打印墨水绘制荧光图案。试验结果表明:羊毛角蛋白和氯金酸的混合溶液调节为碱性(即NaOH浓度为1mol/L)、温度为37℃、反应时间为12h条件下所制备的羊毛角蛋白基金纳米团簇溶液在690nm处发射强烈荧光,所得的金纳米团簇颗粒的尺寸约为2.5nm且均匀分布,制得的打印墨水可以获得清晰的荧光图像。     

羊毛角蛋白保护金纳米簇的制备及表征

利用羊毛角蛋白作为还原剂,制备了具有高荧光性能的金纳米簇。采用荧光光谱仪、紫外-可见吸收光谱仪、傅里叶变换红外光谱仪及透射电子显微镜对试样的结构与性能进行了表征。结果表明,羊毛角蛋白中的巯基在合成金纳米簇的过程中起着关键作用。巯基含量越多,所得到的金纳米簇的荧光强度越高,其中高硫角蛋白合成的金纳米簇(WK_2@AuNCs)的荧光强度是低硫角蛋白合成的金纳米簇(WK_1@AuNCs)的3倍,且前者的粒径要大于后者。分析二级结构含量可知,α-螺旋结构的减少和β-折叠结构的增加是导致荧光强度增加的主要原因。     

亲油性金纳米粒子的制备及表征

利用相转移法合成了在有机溶剂中有很好分散性的十二胺表面修饰金纳米粒子。通过调节金盐与十二胺的物质的量比可以得到不同尺寸分布的金纳米粒子,其中刀（金盐）：n（十二胺）=1：10时,平均粒径最小,并且以选择性沉淀分离法将其分离成尺寸不同、接近单分散的3部分：运用紫外可见光谱（UV-vis）,红外光谱（IR）、X-射线衍射（XRD）和透射电镜（TEM）对金纳米粒子进行了相关表征和分析。     

当归多糖APS-bII的结构特征及体外抗肿瘤作用

从当归(Angelica sinensis(Oliv)Diels)中提取粗多糖,经阴离子交换纤维素柱和Sephadex G-100凝胶柱色谱分离纯化,得白色粉末状多糖APS-bII。采用高效尺寸排阻色谱、红外光谱、高效液相色谱等方法进行了结构的初步分析;采用四甲基偶氮唑蓝比色法观察APS-bII对多种肿瘤细胞的生长抑制作用。结果表明APS-bII为均一组分,分子量为1.3×104Da,由葡萄糖-半乳糖-木糖-阿拉伯糖(8.4:2.7:1.8:1.0)构成,是首次从当归中分离出的杂多糖。APS-bII对多种肿瘤细胞的增殖有抑制作用。     

金纳米簇的制备、表征及对玉米种子萌发的影响

选用模式植物玉米为研究材料,初步评估了金纳米簇在植物中的安全性.结果表明:金纳米簇对玉米种子发芽率没有影响,50~400mg/L的金纳米簇能够促进发芽期间玉米幼苗根和芽的生长.通过切片观察了金纳米簇在玉米幼苗细胞和组织中的吸收情况,发现金纳米簇能够进入玉米根尖脱落细胞以及根部皮层细胞.另外,通过电感耦合等离子体原子发射光谱(ICPAES)测定了金纳米簇在玉米幼苗中的吸收量,证实了金纳米簇未从玉米根部向地上运输.     

光阱中多个金纳米棒的双光子荧光效应及热熔合过程

本文利用单束、波长对应金纳米棒长轴表面等离子共振的飞秒脉冲激光对多个长度为40 nm,直径为10 nm的金纳米棒颗粒进行了光捕获,系统研究了金纳米棒颗粒在共振激光作用下的双光子荧光及光致热熔合效应.实验结果表明,在光阱捕获过程中金纳米棒颗粒会激发出明显的双光子荧光.当多个金纳米棒被光力捕获在光斑中心时,金纳米棒发生热熔化并熔合成大尺寸的金纳米团簇.利用这种单光束光镊熔合技术,我们在玻璃衬底上制备了二维有序的金纳米团簇阵列.这一研究对利用金纳米棒颗粒来制备微纳光子结构及多功能光子器件等具有重要的指导意义.     

香菇多糖分子质量的测定方法研究

采用空间体积排阻色谱法分析香菇多糖.选用protein KW804色谱柱为分离柱,香菇样品经简单的预处理,在示差折光检测器中进行检测,以不同分子质量的标准右旋糖酐（Dextran）为标准品,测定样品中多糖的分子质量分布情况.该方法与其他测定多糖分子质量的方法相比具有快速、简便、准确等优点,是目前较为可行的测定方法.     

以三苯基膦为保护剂制备纳米金溶胶

以三苯基膦(PPh3)为保护剂,采用水相化学还原法制备了纳米金溶胶.利用紫外可见分光光度计和透射电子显微镜对纳米金颗粒的尺寸及形貌进行表征.讨论了还原剂种类与用量、保护剂用量与加入方式、金粒子浓度、溶液pH值等因素对纳米金颗粒粒径、形貌和分散性的影响.结果表明:采用硼氢化钠为还原剂时,PPh3与金质量比为0.02∶1,溶液pH值为7,制得纳米金粒子平均粒径为4~5nm.采用柠檬酸钠为还原剂时,PPh3与金质量比为0.04∶1,柠檬酸钠与金质量比为10∶1,溶液pH=3~4,制得金粒子平均粒径为13~15nm.采用草酸为还原剂时,PPh3与金质量比为0.08∶1,草酸与金质量比为3∶1,金前驱液pH值为6,制得金粒子平均粒径为23~25nm.加入保护剂后,粒子的分散性增强,形状不规则粒子增多.     

嵌段共聚物聚己内酯-聚乙二醇-聚己内酯的合成和表征

以聚乙二醇(PEG)为引发剂在辛酸亚锡催化下引发己酸内酯开环聚合,制备PCL(聚己内酯)-PEG-PCL两亲三嵌段共聚物(PECL).采用红外光谱、体积排阻色谱及核磁共振对该共聚物进行表征,结果表明所合成共聚物具有预期结构.采用差热分析和原子力显微镜研究聚合物的微相分离结构;利用动态光散射测定了共聚物在水中自组装生成的纳米聚集体的粒径.     

Structural effects on the magnetic hyperthermia properties of iron oxide nanoparticles

Magnetic iron oxide nanoparticles(IONPs) are heavily explored as diagnostic and therapeutic agents due to their low cost, tunable properties, and biocompatibility. In particular, upon excitation with an alternating current(AC) magnetic field, the NPs generate localized heat that can be exploited for therapeutic hyperthermia treatment of diseased cells or pathogenic microbes. In this review, we focus on how structural changes and inter-particle interactions affect the heating efficiency of iron oxide-based magnetic NPs. Moreover, we present an overview of the different approaches to evaluate the heating performance of IONPs and introduce a new theranostic modality based on magnetic imaging guided–hyperthermia.     

Chiral ligand-protected gold nanoclusters: Considering the optical activity from a viewpoint of ligand dissymmetric field

Chirality is a geometric property of a physical, chemical, or biological object, which is not superimposable on its mirror image. Its significant presence has led to a strong demand in the development of chiral drugs, sensors, catalysts, and photofunctional materials. In recent years, chirality of nanoscale organic/inorganic hybrids has received tremendous attention owing to potential applications in chiral nanotechnology. In particular, with the recent progress in the syntheses and characterizations of atomically precise gold nanoclusters protected by achiral thiolates, atomic level origins of their chirality have been unveiled. On the other hand, chirality or optical activity in metal nanoclusters can also be introduced via the surface chiral ligands, which should be universal for the nanosystems. This tutorial review presents some optically-active metal (gold) nanoclusters protected by chiral thiolates or phosphines, and their chiroptical (or circular dichroism; CD) properties are discussed mostly from a viewpoint of the ligand dissymmetric field scheme. The examples are the gold nanoclusters protected by (R)-/(S)-2-phenylpropane-1-thiol, (R)-/(S)-mercaptosuccinic acid, phenylboronate-D/L-fructose complexes, phosphine sulfonate-ephedrinium ion pairs, or glutathione. Some methodologies for versatile asymmetric transformation and chiroptical controls of the nanocluster compounds are also described. In the dissymmetric field model as the origin of optical activity, the chiroptical responses of the gold nanoclusters are strongly associated with coupled oscillator and/or CD stealing mechanisms based on the concept of induced CD (ICD) derived from a perturbation theory, so on this basis, some characteristic features of the observed CD responses of chiral ligand-protected gold nanoclusters are presented in detail. We believe that various kinds of origins of chirality found in ligand-protected gold nanoclusters may provide models for understanding those of many related nanomaterials.     

质谱技术在筛选肺癌血清差异多肽与蛋白质的应用

采用凝胶排阻层析(SEC)与MALDI-TOF质谱非在线联用技术研究男性血清中多肽与蛋白质的组成与分布. 实验结果表明,分离介质Sephadex G-75比Sephadex G-50和Sephadex G-100更加适合血清多肽与蛋白质的预分离. 男性血清经Sephadex G-75层析柱预分离和MALDI-TOF质谱分析后,可获得56个多肽与蛋白质的分子离子峰. 差异比对实验表明,在正常人与患有肺癌疾病的男性血清中,正常男性血清存在着7种不同质荷比(m/z)的差异多肽与蛋白质,其m/z的比值分别为4 808,6 867,6 912,7 036,27 990,28 120,50 687;反之,在肺癌患者血清中发现差异的m/z值为6 139,6 544,8 417,8 480,11 109. 这些差异多肽与蛋白质为临床诊断正常人和患有肺癌疾病患者的标记物提供一条途径.     

Three-dimensional atomic-scale structure of size-selected gold nanoclusters

An unambiguous determination of the three-dimensional structure of nanoparticles is challenging. Electron tomography requires a series of images taken for many different specimen orientations. This approach is ideal for stable and stationary structures. But ultrasmall nanoparticles are intrinsically structurally unstable and may interact with the incident electron beam, constraining the electron beam density that can be used and the duration of the observation. Here we use aberration-corrected scanning transmission electron microscopy, coupled with simple imaging simulation, to determine with atomic resolution the size, three-dimensional shape, orientation and atomic arrangement of size-selected gold nanoclusters that are preformed in the gas phase and soft-landed on an amorphous carbon substrate. The structures of gold nanoclusters containing 3096 atoms can be identified with either Ino-decahedral, cuboctahedral or icosahedral geometries. Comparison with theoretical modelling of the system suggests that the structures are consistent with energetic considerations. The discovery that nanoscale gold particles function as active and selective catalysts for a variety of important chemical reactions has provoked much research interest in recent years. We believe that the detailed structure information we provide will help to unravel the role of these nanoclusters in size- and structure-specific catalytic reactions. We note that the technique will be of use in investigations of other supported ultrasmall metal cluster systems.     

基于适配体的胶体金色谱层析试纸条快速检测肌酸激酶同工酶

研究基于适配体的胶体金色谱层析试纸条快速检测肌酸激酶同工酶,用于揭示长期飞行下航天员潜在的心肌和肌肉损伤.利用SELEX方法筛选得到的肌酸激酶同工酶适配体,并优选出与肌酸激酶同工酶有较强亲和能力的核酸适配体应用于胶体金免疫层析试纸条,通过优化胶体金颗粒大小、缓冲液浓度等条件,成功建立了一种基于适配体的胶体金试纸法用于CK-MB的快速检测.实验结果表明,通过基于磁珠的核酸适配体筛选方法筛选出的与肌酸激酶同工酶有亲和力的核酸适配体,能够用于构建适配体-适配体夹心胶体金免疫层析试纸条并成功应用于82 nM以上的肌酸激酶同工酶的快速、可视化检测,同时,该免疫层析试纸条具有良好的特异性和稳定性,可用于未来空间医学即时检测.     

Copper nanoclusters: Synthesis,characterization and properties

Metal nanoclusters with a core size smaller than 2 nm have attracted much attention because of their unique physical and chemical properties.Among the studied metal nanoclusters,gold and silver have been studied extensively by size-controlled synthesis, structural characterization and properties investigations.Recently,considerable research effort has been devoted to the investiga- tion of copper nanoclusters.In this review,we highlight recent progress in the study of copper nanoclusters in terms of synthesis methods,characterization techniques and their novel optical and catalytic properties.     

羟丙基-β-环糊精修饰纳米碳管载钯催化剂的制备及其甲酸氧化性能

以羟丙基-β-环糊精(HP-β-CD)为添加剂修饰碳纳米管为复合载体,常温常压下,成功合成了Pd纳米簇状结构,并用于甲酸的电催化氧化.XRD及TEM结果表明,制备出的Pd纳米簇状结构由粒径均匀,约为3.6nm的纳米颗粒组成,且高度分散沉积在载体表面.循环伏安测试结果表明,催化剂Pd/HP-β-CD-MWCNTs对甲酸氧化表现出了较高的催化活性和电化学比表面积.研究表明,在HP-β-CD存在条件下,将Pd纳米簇沉积在未作处理的碳纳米管上制备的催化剂适合应用于甲酸燃料电池.     

C_(60)系列的高效制备

采用石墨等离子体放电方法,建立了一套高效率制备C_(60)系列的工艺,成功地得到了纯的C_(60)。结果表明,反应气氛、电流密度与电极间距是影响制备过程的主要因素,氧化铝的活性、粒度及色谱柱的装填质量决定着C_(60)的分离效果。     

金原子簇催化应用的研究进展

在最近的10年里,原子精确的金原子簇(AunLm,L为有机配体)已经被证明是一种新型的纳米金催化剂.不同尺寸的AunLm催化剂表现出独特的电子和晶体结构,为关联催化性能和催化剂结构的内在关系及研究纳米金催化的化学反应机制提供了新的研究平台.在这篇综述中,主要介绍金原子簇催化剂在催化反应中的应用,如选择性氧化和加氢,及C—C偶联反应等,同时,也讨论金原子簇催化剂的尺寸效应、配体效应(例如,芳香族vs脂肪族)、杂金属掺杂(如铜、银、钯、铂)等.最后,在原子尺度上研究了金原子簇催化的反应机制以及结构-活性的构建关系.