用于生物标记的半导体量子点研究

半导体量子点的独特光学性质使之成为理想的荧光探针材料，在生物医学领域具有广阔的应用前景．本文评述了目前量子点合成、表面修饰、结合生物分子的方法，以及半导体量子点在生物标记应用中相对于传统有机染料的优点．     

新型量子点修饰分子灯塔探针及其作为DNA传感器应用

以CdTe量子点为能量供体,BHQ-1为能量受体构建了一种基于能量共振转移原理(FRET)的分子灯塔探针.能量供体与受体分别连接于分子灯塔探针DNA链的两端,由于探针的自杂交作用可将能量供体与受体之间的距离控制在1～10nm之间,并且供体的荧光发射光谱与受体的紫外吸收光谱存在一定程度的重叠,因此满足FRET原理.此探针体系可以作为DNA传感器较好的区分与探针碱基序列完全匹配的DNA、单碱基错配的DNA、完全不匹配的DNA.     

水溶性黄绿色荧光硅量子点合成及对miRNA-21的检测

相对于传统的Ⅱ/Ⅵ族、Ⅲ/Ⅴ族量子点,硅量子点以其良好的生物相容性和优越的光学性能在生物传感、荧光探针及医学诊断等领域得到广泛应用。以氨基乙基氨基异丁基甲基二甲氧基硅烷为硅前体,抗坏血酸钠和抗坏血酸为还原剂,水热法合成了水溶性黄绿色荧光硅量子点。并利用红外光谱仪、X-射线光电子能谱仪、透射电子显微镜对硅量子点进行结构表征。对反应的影响因素如水浴反应时间、水浴温度、反应物的物质的量比、还原剂比例进行了考察和优化。研究表明,制备的硅量子点对Cy5具有明显的淬灭行为。基于硅量子点对Cy5的淬灭行为,建立了Cy5标记单链DNA用于检测肿瘤标志物miRNA-21的方法。该方法的检出范围为0. 5～40 nmol/L,检出限为0. 15 nmol/L,并具有良好的区分单碱基错配的能力。     

量子点作为离子探针的分析应用

量子点（quantumdots,QDs）又称半导体纳米晶（semiconductornanocrystals）是一种高效的光致发光纳米晶体。近年来,量子点表面化学的快速发展,使其得到了越来越广泛的应用。本文评述了近年来量子点在无机离子以及H’分析中的应用及进展,阐述了量子点可用于离子探针的机理,介绍了量子点作为H’探针在生物以及小分子检测中的应用并对其未来的发展方向进行了展望。     

叶酸受体介导的CdTe/ZnS核-壳量子点的细胞成像

[目的]构建叶酸分子靶向复合荧光探针,表征基本理化性质,标记细胞。[方法]以巯基乙酸为稳定剂,采用水相合成法制备CdTe/ZnS核壳型量子点。利用荧光分光光度计和红外光谱仪分别对其光致发光和吸收光谱进行表征。采用聚乙烯亚胺作为连接叶酸与量子点的偶联剂,制备叶酸受体靶向的复合荧光探针,并通过透射电镜对其形貌进行表征。在荧光倒置显微镜下观察已知细胞表面叶酸受体阳性的癌细胞对荧光探针的表达图像。[结果]复合荧光探针的光谱性能良好,颗粒分散均匀,能够标记细胞。[结论]复合荧光探针能够标记大鼠肝癌细胞,为其作为临床血液肿瘤治疗中潜在的靶向标记提供依据。     

量子点荧光探针在生物医学领域的研究进展

量子点是一种新型的半导体荧光纳米材料,由于其特殊的纳米结构所导致的表面、介电、量子等效应而具有许多优异的光学性能,近年来在分析化学、生物医学等领域得以快速应用和发展.介绍了量子点的制备方法、表面修饰及量子点荧光探针在生物医学领域的应用进展,并对未来的发展方向作出了展望.     

量子点的合成、表征及其作为功能性探针的快速识别应用进展

该文就量子点的合成方法,表征技术以及作为功能性探针的快速识别应用进行较为详尽的评述,展望了量子点作为功能性探针应用于快速识别领域的发展趋势。     

量子点纳米材料探针及其在肿瘤影像中的应用

针对现有量子点影像探针存在荧光性质不可控、生物毒性强的问题,本研究结合现有的CuInS量子点探针,研究制备出一种掺杂Zn离子可简易合成的ZCIS/ZnS量子点纳米探针,并通过改进其水溶性,得到一种可直接应用于医学肿瘤影像的改进ZCIS/ZnS量子点纳米探针。为提高该量子点纳米探针的靶向性,研究根据EDC偶联的原理,通过将改进ZCIS/ZnS量子点纳米探针与cRGD多肽进行偶联,得到ZCIS/ZnS-cRGD量子点纳米探针,并从结构形态、细胞毒性和离体荧光3个方面重点评估了该量子点纳米探针,并通过实验论证了其有效性和实用性。实验结果证明,本研究制备的ZCIS/ZnS-cRGD量子点纳米探针是一种有效的肿瘤靶向探针,可用于实际肿瘤靶向检测。     

地高辛标记HBV DNA探针的应用

按随机引物法以地高辛标记HBV DNA探针,与按缺口翻译法以~(32)P标记的探针进行了比较。这两种探针与乙肝血源疫苗及患者血清标本中HBV DNA进行杂交,结果两种探针均可要出1pg同源序列DNA,而地高辛标记的探针,在0.1Pg水平仍可呈现弱着色反应。该探针在一20℃储存6个月,其敏感性不减弱。这种探针在常规诊断实验室更易推广使用。     

用光敏生物素标记的探针检测人用鼠源单抗中残余DNA

将培养至对数期的Ag8．653小鼠骨髓癌细胞经裂解、抽提、RnaseA处理和纯化，获得A260nm／A28nm，为2.013、电泳为一条区带的纯化的小鼠骨髓瘤细胞全DNA；该DNA经不同处理，标记两个探针，即全DNA通过缺口转移法，用‘中标记和全DNA用光敏生物素（军事医学科学院二所提供）标记。在比较灵敏度时，将纯化的未标记的小鼠骨髓癌细胞全DNA分别点在两张硝酸纤维膜上（每张膜上分别含20Pg、10pg和5pg），再用’于和光敏生物素标记的探针分别与这两张膜进行斑点杂交。在用光敏生物素标记的探针检测单抗样品时，随机取3批单克隆抗体（分别经…     

荧光硫量子点制备及应用研究进展

硫量子点具有发光强度高、毒性低和光化学性能稳定等优势，广泛应用于细胞成像、光电转换和化学催化等领域。鉴于此，本文系统综述了硫量子点的合成方法，光学性能和应用背景。硫量子点的合成方法可分为“自下而上法”和“自上而下法”，对比发现“自上而下法”合成的硫量子点具有更高的荧光量子产率。分析了硫量子点的光学性质，表明其具有紫外吸收特性、荧光特性、光致发光、电化学发光以及光学稳定性。最后，系统介绍了硫量子点在荧光探针、生物成像以及发光器件等领域的重要应用。基于以上分析，深刻剖析了当下硫量子点在前沿应用中亟待解决的问题，展望了未来硫量子点在生物医学、光电催化等新行业、新领域的发展方向。     

Fabrication of single-walled carbon nanotubes dotted with Au nanocrystals: Potential DNA delivery nanocarriers

Single-walled carbon nanotubes (SWCNTs) dotted with Au nanocrystals (Au-SWCNTs) were fabricated by using a two-phase reduction of hydrogen tetrachloroaurate in the presence of thiol groups anchored to SWCNTs for their potential applications in DNA (deoxyribonucleic acid) delivery. To allow a surface reaction on SWCNTs during the metal nucleation and growth processes, Au nanocrystals were grown using a two-phase system. Raman, XPS and transmission electron microscopy results show that the Au nanocrystals were grafted primarily to the sidewalls of the SWCNTs. DNA probes were immobilized on Au-SWCNTs by the conjugation of DNA functionalized at the 3′ end with a thiol group with Au dots of SWCNTs, followed by hybridizion of complementary oligonucleotides, as verified by fluorescence-based measurements. To investigate whether the target DNA hybridized to DNA probes immobilized on Au-SWCNTs, 618-base-pair fragments of amplified DNA were prepared by polymerase chain reaction using plasmid pET-22b as a template. Atomic force micrograph (AFM) images show that the nanorod-bound DNA is recognizable with excellent specificity, indicating the potential use of such material as a versatile gene delivery carrier in gene-based disease therapy.     

Simplistic hydrothermal synthesis approach for fabricating photoluminescent carbon dots and its potential application as an efficient sensor probe for toxic lead(II) ion detection

The past decade has witnessed a variety of members of the carbon family along with exposure of carbon dots due to their magnificent properties in sensing, bioimaging, catalytic applications, biomedical fields, and so on. Herein, we report the simple hydrothermal method to fabricate photoluminescent doped carbon quantum dots for the detection of noxious lead(II) ions. Lead(II) ion is very venomous for both the environment and human health for which its detection is demanded area in the research field. The as-prepared carbon dots show excellent photostability, low toxicity and significant photoluminescence properties along with good water solubility. Along with these properties, carbon dots have a quantum yield of approximately 15%. In the practical field of application, these carbon dots have been used as sensing probes for the detection of lead(II) ions with a detection limit of 60 nmol·L^–1. The fluorescence intensity of carbon dots was remarkably quenched in the presence of the lead(II) ion selectively among all the tested metal ions. Furthermore, we have studied the Stern–Volmer relationship for lead(II) quenching along with the explanation of the probable quenching mechanism. Ability of the doped carbon dots in heavy metal ions sensing in an environmental sample was demonstrated.     

量子点的合成及在生物分析中的应用

综述了量子点的性质,比较了量子点与传统有机染料分子作为荧光标记试剂的优缺点,对国内外量子点的合成进行了归纳,同时对量子点在生物体系中的应用和前景进行了综述和展望。     

DNA分子荧光探针

本文综述了各种DNA荧光探针的结构特征荧光性质和与DNA的作用方式，主要涉及了6类化合物：吖啶和菲啶类、菁类染料、荧光素和罗丹明类、噻嗪和恶嗪类染料、BODIPY类染料以及其它类别的探针，概述了DNA探针在生物分子分析方面的应用，并展望了DNA荧光探针的发展趋势和应用前号。有47篇参考文献。     

量子点的合成研究

量子点（半导体纳米晶）是纳米尺度的微小发光粒子。作为新型的生物标记试剂,具有比传统的有机染料更好的光谱特性和光学稳定性。本文对量子点的光学性质、制备方法做一简要综述。     

Fluorescent,Recombinant-Protein-Conjugated,Near-Infrared-Emitting Quantum Dots for in Vitro and in Vivo Dual-Color Molecular Imaging

Near-infrared (NIR)-emitting fluorescent probes are widely used for molecular imaging at the whole-body level. However, NIR-emitting fluorescent probes emitting over λ=700 nm are not suitable for molecular imaging at the cellular level, because most of the conventional fluorescence microscopes have very low optical sensitivity in the NIR region. Thus, to achieve fluorescence imaging at the cellular and whole-body levels by using single probes, visible and NIR-emitting dual-color fluorescent probes are desirable. For dual-color fluorescence molecular imaging, we synthesized fluorescent, recombinant-protein-conjugated, NIR-emitting quantum dots (QDs), in which the recombinant protein consists of enhanced green fluorescent protein (EGFP) and the immunoglobulin binding domain (B1) of protein G. This dual-color fluorescent QD probe binds the Fc region of immunoglobulin G (IgG) through its B1 domain at the QD surface and acts as a molecular-imaging probe at both the cellular and whole-body levels. In this paper, we present the synthesis of fluorescent, recombinant protein (HisEGFP-GB1)-conjugated, NIR-emitting QDs and their application to the dual-color molecular imaging of breast cancer cells in vitro and in vivo.     

Aptamer-Functionalized Hybrid Nanostructures for Sensing,Drug Delivery,Catalysis and Mechanical Applications

Sequence-specific nucleic acids exhibiting selective recognition properties towards low-molecular-weight substrates and macromolecules (aptamers) find growing interest as functional biopolymers for analysis, medical applications such as imaging, drug delivery and even therapeutic agents, nanotechnology, material science and more. The present perspective article introduces a glossary of examples for diverse applications of aptamers mainly originated from our laboratory. These include the introduction of aptamer-functionalized nanomaterials such as graphene oxide, Ag nanoclusters and semiconductor quantum dots as functional hybrid nanomaterials for optical sensing of target analytes. The use of aptamer-functionalized DNA tetrahedra nanostructures for multiplex analysis and aptamer-loaded metal-organic framework nanoparticles acting as sense-and-treat are introduced. Aptamer-functionalized nano and microcarriers are presented as stimuli-responsive hybrid drug carriers for controlled and targeted drug release, including aptamer-functionalized SiO₂ nanoparticles, carbon dots, metal-organic frameworks and microcapsules. A further application of aptamers involves the conjugation of aptamers to catalytic units as a means to mimic enzyme functions “nucleoapzymes”. In addition, the formation and dissociation of aptamer-ligand complexes are applied to develop mechanical molecular devices and to switch nanostructures such as origami scaffolds. Finally, the article discusses future challenges in applying aptamers in material science, nanotechnology and catalysis.