金属纳米团簇在生物医学领域的研究进展

金属纳米团簇具有独特的超小尺寸和光、磁、催化等性能,以及优异的生物相容性等特征,在生物医学研究中备受关注.但其存在发光效率偏低、活体代谢速度较快等问题.为此介绍近几年通过合成优化和发光调控等方法提高金属纳米团簇的检测与成像灵敏度和肿瘤诊疗能力的研究进展.探究金属纳米团簇的肾代谢和生物酶催化性能;开发具有精确原子数、高效生物相容性和肿瘤靶向性的金属纳米团簇;突破其近红外发光量子产率限制,提高光声-磁共振造影等性能,将是未来该领域研究的重要方向.     

基于金纳米簇构建荧光传感方法在生化分析中的应用研究

近几年来,基于配体保护的金纳米簇的合成工艺迅速发展,采用各种生物和有机化合物合成配体,多种结构性质和功能迥异的金纳米簇被成功制备.并且相较于其他金属纳米簇,金纳米簇在表现出良好生物相容性和物化性质的同时还具有较高的稳定性和合成效率,受到了各个领域的广泛关注,尤其是在化学和生物物质的传感领域.本文综述了采用荧光传感方法,...     

有机分子笼封装金属纳米团簇的合成策略与催化应用

金属纳米团簇是由若干金属原子组成的纳米材料，尺寸介于单个金属原子和纳米颗粒之间，具有独特的几何和电子结构，在催化反应中展现出良好的性能.然而裸露的金属纳米团簇由于表面能较高，在催化过程中容易聚集失活.近年来，有机分子笼(organic molecular cages,OMCs)作为一种新兴的多孔材料受到了广泛关注.将金属纳米团簇封装在有机分子笼的限域空间内不仅可以提高其粒径均一性，还可以提高稳定性.有机分子笼的孔道结构完全开放，封装在其内部的金属纳米团簇在氧化、还原、偶联、产氢等反应中仍保持较高的催化活性.本文简要总结了有机分子笼封装金属纳米团簇的合成策略以及这类材料在催化领域的应用.     

精确尺寸巯基保护贵金属纳米团簇的合成进展

金属纳米团簇作为凝聚态物质的初始形态之一,在金属原子/分子化合物向金属纳米颗粒形成的过程中起着桥梁作用.因其具有量子局限效应,团簇往往表现出特异的光学、催化等性质.近几十年来的研究发现,单个原子的改变会对团簇的几何结构以及电子结构产生显著的影响.同时,精确的结构可以有效地建立结构与性质之间的关系.因此,合成具有精确结构的纳米团簇在近年来受到广泛关注.笔者对巯基保护精确结构金属纳米团簇合成方法的建立以及发展进行了综述.     

基于双配体稳定的金纳米簇荧光检测生物硫醇

生物硫醇在生物系统中起着关键的作用,对生物硫醇快速灵敏准确的检测对于一些疾病的临床诊断具有重要意义.提出一种基于双配体稳定的金纳米簇的合成过程用于快速检测生物硫醇的荧光分析方法.以巯基十一烷酸(MUA)和L-丝氨酸(L-Ser)为配体能够快速制备得到荧光金纳米簇,合成的金簇在600 nm处有明显的强荧光发射峰.在金簇的合成过程中,当体系存在生物硫醇时,金簇的荧光会发生猝灭,荧光猝灭的程度与生物硫醇的浓度相关.该检测方法对于半胱氨酸的检测线性范围在8. 3 133. 3μmol/L,检测限为1. 09μmol/L.该分析方法不仅能够快速制备得到荧光金纳米簇,且具有较好的灵敏度和选择性,并将材料制备和目标物分析两个过程相结合,有效缩短了分析时间,提高了检测效率.另外,该方法在人血清中表现出良好的检测结果,说明该检测方法的具有较好的实用性.     

金属纳米团簇在电化学领域的应用研究进展

尺寸小于2nm的金属纳米团簇是由几个到几百个原子组成的纳米结构材料.对于金属纳米团簇,由于其大部分甚至所有金属原子可能暴露于表面而具有高的表面原子比例,该独特的原子堆积结构使其具有高的表面活性,因此其在催化反应中具有重要应用价值.同时,其明确的原子排列和堆积结构使其可作为模型催化剂,用于研究纳米结构-性能之间的关系.笔者简要总结了近年来金属纳米团簇的研究进展和现状,重点总结了其在电化学领域的应用,包括电催化和电化学传感,最后对其未来在电催化和电分析领域的应用前景进行了展望.     

金属团簇化学研究进展

<正>金属纳米团簇作为一种凝聚态物质的初始形态,在金属原子向金属纳米颗粒形成的过程中起着桥梁作用.由于其具有独特的物理化学性质,近年来受到了广泛关注,对其的研究已成为纳米领域的一个热点课题.相比于传统的金属纳米颗粒,金属纳米团簇由于具有单一分布的尺寸以及精确的结构等特点,在对凝聚态物质物理化学性质(如光学、催化性质)的机制阐述方面有着不可取代的理论研究价值.不仅如     

小尺寸Au-Ag合金团簇负热容的模拟研究

利用分子动力学方法,研究了AuN-XAgX(N=144;X=0,24,48,72,96,120和144)纳米团簇熔化过程中的热力学性质.计算模型采用原子嵌入模型(EAM)和Johnson提出的贵金属原子间相互作用势函数.模拟结果表明:金银合金团簇在熔点附近具有负热容特性,负热容主要由相变前后团簇内部结构突变引起.     

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.     

金纳米团簇荧光探针的合成与生物检测应用

近年来,纳米技术发展迅速。荧光金纳米材料展现出的独特光学特性使其在生物检测和医学诊断中表现出了很好的应用前景。通过改变配体或者生物支架合成的各种荧光金纳米团簇(gold nanocluster,Au NCs),在传感检测、医学成像和光电子学等领域具有潜在的应用前景。就荧光和共振光散射技术和方法对水溶性的荧光金纳米团簇的合成以及检测机理作出介绍,并简单总结了金纳米团簇作为荧光探针在生物检测,包括金属离子、阴离子、有机小分子、蛋白质和核酸等各种分析物检测中的应用。同时,评述和展望了荧光金纳米团簇研究的发展方向和应用前景。     

Near-infrared fluorescent aptamer-templated silver nanoclusters facilely synthesized for cellular imaging applications

Fluorescent metal nanoclusters(NCs)have received extensive attention for their potential uses in bionanotechnology.Here,we develop a facile strategy to synthesize near-infrared fluorescent silver nanoclusters(Ag NCs)stabilized by MUC1 aptamer.The MUC1-Ag NCs are characterized by UV–Vis absorption spectroscopy,fluorescence spectroscopy,transmission electron microscopy,and fluorescence lifetime.These results indicated that the MUC1-Ag NCs possess bright near-infrared luminescence,high stability,and excellent biocompatibility.The cellular imaging of MUC1-Ag NCs by confocal laser microscopy demonstrated them to be promising candidates as novel fluorescent probes for biomedical application.     

发光铜纳米粒子的制备及其在生化传感、环境监测中的应用综述

发光铜纳米簇具有与金、银贵金属纳米簇相媲美的荧光性质,还具有原料储量丰富、制备经济、合成过程简便等优点,具有广阔的应用前景。系统地介绍了铜纳米簇的主要性质、制备方法及应用现状,重点总结了近年来荧光铜纳米簇在生化传感器、生物探针、细胞成像、环境标志物检测等领域的应用进展。     

动力学控制合成原子精确的银纳米团簇及催化还原4-硝基苯酚

Synthesizing atomically precise Ag nanoclusters (NCs), which is essential for the general development of NCs, is quite challenging. In this study, we report the synthesis of high-purity atomically precise Ag NCs via a kinetically controlled strategy. The Ag NCs were prepared using a mild reducing agent via a one-pot method. The as-prepared Ag NCs were confirmed to be Ag₄₉(D-pen)₂₄ (D-pen: D-penicillamine) on the basis of their matrix-assisted laser desorption ionization time-of-flight mass spectrometric and thermogravimetric characteristics. The interfacial structures of the Ag NCs were illustrated by proton nuclear magnetic resonance and Fourier-transform infrared spectroscopy. The Ag NCs were supported on activated carbon (AC) to form Ag NCs/AC, which displayed excellent activity for the catalytic reduction of 4-nitrophenol with a kinetic reaction rate constant k of 0.21 min?1. Such a high k value indicates that the composite could outperform several previously reported catalysts. Moreover, the catalytic activity of Ag NCs/AC remained nearly constant after six times of recycle, which suggests its excellent stability.     

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.     

金属离子掺杂TiO2纳米晶簇室温光透射谱

报道了金属离子掺杂TiO₂纳米晶簇室温光透射谱实验测量结果。金属掺杂使TiO₂纳米晶簇室温光透射值明显减小。而且,金属掺杂引起TiO₂纳米晶簇室温光透射值变化谱线是非线性变化曲线。在变化曲线上存在位置不等的极大值。