CdTe量子点荧光探针在生物分析中的应用

目的 探讨巯基丙酸包被的CdTe量子点在生物分析中应用价值.方法 水相中合成CdTe量子点并进行巯基丙酸包被,并对其进行了荧光发射光谱及透射电子显微镜成像表征;将量子点与亲和素连接、制备成量子点荧光探针;应用激光扫描共聚焦显微术观察量子点荧光探针标记小鼠腹腔巨噬细胞(peritoneal macrophage,PMΦ)MHCⅡ抗原的表达;以H22肝癌细胞为靶细胞,MTT法观察量子点的生物相容性.结果 CdTe量子点粒径均匀,具备良好的光学性能;量子点荧光探针标记细胞具有较强的荧光表达;量子点在一定浓度范围内对细胞的毒性小.结论量子点荧光探针能对固定的组织细胞进行标记,同时具有较好的生物相容性,可对活细胞进行直接或动态标记.     

量子点技术在生物成像中的应用进展

目的：介绍量子点材料的特点及其在生物成像中的应用,并对其前景进行展望. 资料来源：应用计算机检索PubMed 1998-01/2007-04关于量子点生物成像文章.检索词“quantum dots,biological imaging,bioconjugates,fluorescence imaging”限定文章的语言种类为“English”. 资料选择：对资料进行初审,纳入标准：①量子点的特点及表面修饰.②量子点在不同的生物组织细胞中的成像应用.排除标准：重复性研究. 资料提炼：共收集到符合上述要求的文献31篇,关于量子点的特点及表面修饰的14篇,关于量子点在不同的生物组织细胞中的成像应用17篇. 资料综合：量子点（quantum dots,QDs）是一种新型纳米荧光材料,现有技术能将量子点与生物分子结合在一起作为一种高亮度而稳定的荧光探针用于生物成像.作为一种新型的荧光纳米材料量子点,在多种类型的生物成像研究中较传统的有机荧光素和荧光蛋白而言具有更加优越的特性,使研究者能够以一种全新的方法对单个细胞、组织、甚至活动物的基因、蛋白质和药物靶点进行研究,为疾病机制的阐明和临床诊疗提供有力帮助. 结论：量子点荧光标记材料具有信号稳定、标记简便、检测灵敏的优点,在生物成像中具有良好的应用前景.     

量子点:肿瘤诊断和治疗一体化荧光探针

目的量子点光激发可发射荧光,具有长时间、多目标和灵敏性高等独特的光学性质,在肿瘤细胞标记和生物应用中得到了广泛应用。通过量子点标记定位肿瘤细胞,对寻找癌变部位具有指导作用。量子点作为能量供体,在肿瘤光动力学治疗研究得到关注。本文简要介绍量子点光学特性,综述量子点荧光探针在肿瘤诊断和肿瘤光动力学治疗方面应用研究。     

量子点作为荧光标记物在临床检测方面的应用研究进展

量子点作为一种极具应用前景的信号标记,与传统有机荧光染料相比,具有宽而有效的激发谱,窄而对称的发射谱,高的荧光量子效率,优异的光化学稳定性,方便、灵活的表面可修饰性,且不同尺寸量子点可以被同一波长的光激发,发射不同波长的荧光等独特的光学特性[1-2],在生物分析中的应用日益广泛,尤其有望在多重检测方面发挥重要的作用。     

量子点在泌尿系肿瘤中的应用价值

量子点（quantumdots，QDs）是一种具有独特荧光性质的纳米半导体晶体，因其独特的荧光效应在生物传感、生物分析、细胞成像和动物活体靶向研究等方面具有潜在的应用价值而受到生物医学界的广泛关注。     

量子点在生物医学领域的应用

生命科学的高速发展离不开新技术新方法的应用。近些年来,量子点在生物医学领域的应用已经成为人们广泛关注的研究热点之一,量子点在体内外成像,靶向标记特异组织和细胞等方面均取得了新的进展。相对于传统的荧光染料分子而言,量子点具有其独特的特性及优点。本文对近年来量子点在生物医学领域的诸多应用及进展做一综述。     

量子点标记技术在分子生物学中的研究进展

量子点又称半导体纳米晶体,它可发出激发荧光,具有荧光强度高、稳定性好和发射光谱可调等特性,是同时检测多种信号的理想材料。这些独特性质使其更广泛的应用于分子生物学领域。对量子点进行功能化修饰,如偶联抗体等活性生物后,将在细胞器定位、信号传导、原位杂交、病原体的快速检测和体内示踪等方面的研究发挥巨大潜力。文中分别从细胞生物学、基因标记、病原体检测、活体示踪等方面探讨了功能化量子点在分子生物学中的最新进展。     

小波变换在量子点编码识别中的应用

背景:为实现更多种类的量子点编码,量子点的荧光发射峰必定出现重叠,这就造成了量子点编码识别的困难.目的:应用小波变换对重叠峰展开技术,对两种相邻波长量子点的编码进行识别.方法:在显微镜引导下,以375 nm的紫外光激发单个量子点编码微球的荧光光谱,被光纤光谱仪采后,应用小波变换对数据多维展开,然后经过样条函数处理,再通过小波反变换重构波谱展开的光谱.结果与结论:为了使处理数据的长度为2~n,在原始数据进行了插值运算.经过小波变换处理后,峰位置保持不变,能够提取编码荧光光谱的特征值.通过小波变换,混合微球的荧光光谱被展开,能够识别出两种量子点编码,提高了识别的分辨率.通过提高对相邻光谱的编码的识别,量子点编码的颜色必将增加,从而显著丰富编码的信息量.结果提示用小波变换对光谱进行处理后,可以实现对不同波长的荧光展开,提高了识别效率,为实现肿瘤标志物的高通量检测奠定基础.     

石墨烯量子点在生物医学中的应用:进展与挑战

与其他纳米材料相比,以石墨烯量子点为基础的复合纳米材料,具有许多独特的理化性质,因此,在多个应用研究领域特别是在生物医学方面得到了高度关注。本篇综述中,笔者主要着眼于石墨烯量子点在生物传感器、体内外成像以及疾病治疗等领域的研究进展,并讨论了石墨烯量子点尚未解决以及在生物医学应用中有争议的话题,展望了石墨烯量子点为基础的纳米材料在生物医学方面的应用前景。     

量子点在生物医学标记分析中的应用研究

在生命科学及生物学领域,以往多采用有机染料标记生物大分子和细胞,来研究蛋白质之间的相互作用以及对细胞功能的影响等。然而有机染料存在着诸多缺点限制了他的应用,量子点（quantum dot,QDs）在10年前还鲜为人知,近年来其作为新型的生物标记物克服了有机染料的许多缺点,逐渐被人们认识并关注。作为半导体纳米晶体,他独特的光电特性为荧光探针的设计应用提供了空前的前景,极大地扩展了荧光成像在细胞与活体动物中的应用。现对其进行简要综述。     

Semiconductor quantum dots: synthesis and water-solubilization for biomedical applications

BACKGROUND: Quantum dots (QDs) are generally nanosized inorganic particles. They have distinctive size-dependent optical properties due to their very small size (mostly < 10 nm). QDs are regarded as promising new fluorescent materials for biological labeling and imaging because of their superior properties compared with traditional organic molecular dyes. These properties include high quantum efficiency, long-term photostability and very narrow emission but broad absorption spectra. OBJECTIVE/METHODS: Recent developments in synthesizing high quality semiconductor QDs (mainly metal-chalcogenide compounds) and forming biocompatible structures for biomedical applications are discussed in this paper. Results/conclusions: This information may facilitate the research to create new materials/technologies for future clinical applications.     

Semiconductor quantum dots: synthesis and water-solubilization for biomedical applications

Background: Quantum dots (QDs) are generally nanosized inorganic particles. They have distinctive size-dependent optical properties due to their very small size (mostly < 10 nm). QDs are regarded as promising new fluorescent materials for biological labeling and imaging because of their superior properties compared with traditional organic molecular dyes. These properties include high quantum efficiency, long-term photostability and very narrow emission but broad absorption spectra. Objective/methods: Recent developments in synthesizing high quality semiconductor QDs (mainly metal-chalcogenide compounds) and forming biocompatible structures for biomedical applications are discussed in this paper. Results/conclusions: This information may facilitate the research to create new materials/technologies for future clinical applications.     

CdSe quantum dots labeled Staphylococcus aureus for research studies of THP-1 derived macrophage phagocytic behavior

A simple biological strategy to couple intracellular irrelated biochemical reactions of staphylococcus aureus CMCC 26003 (S. aureus) with inorganic metal ions to synthesize cadmium selenide quantum dots (CdSe QDs) was demonstrated. Correspondingly, S. aureus as living matrices are internally generated and labeled with fluorescent QDs by the smart strategy. Several key factors in the process of biosynthesis were systematically evaluated. At the same time, ultraviolet-visible (UV-Vis), photo-luminescence (PL), inverted fluorescence microscopy and transmission electron microscopy (TEM) were utilized to study the characters of the as produced CdSe QDs. In addition, cytotoxicity and photostability of the QDs containing bacteria were also tested and evaluated as a whole. The results showed that intracellular CdSe nanocrystals had successfully formed in S. aureus living cells, which were less toxic, highly fluorescent and photostable. These fluorescent S. aureus bacteria were next applied as invading pathogens as well as fluorescent bioprobes for exploring the phagocytic behavior of THP-1-derived macrophage. Results proved that internal CdSe QDs labeling had no significantly adverse effects compared with the kind of infection reference, fluorescein isothiocyanate (FITC) stained S. aureus pathogen. Assuredly, the methods presented here provide researchers with a useful option to analyze the behavior of S. aureus as a type of infectious pathogen, which would also help understand the complex interplay between host cells and the invading bacteria on molecular level.

A simple, novel labeling strategy to obtain a fluorescent bacterial probe and research phagocytosis of macrophages.     

Biocompatible quantum dot-antibody conjugate for cell imaging,targeting and fluorometric immunoassay: crosslinking,characterization and applications

Quantum dots (QDs) are important fluorescent probes that offer great promise for bio-imaging research due to their superior optical properties. However, QDs for live cell imaging and the tracking of cells need more investigation to simplify processing procedures, improving labeling efficiency, and reducing chronic toxicity. In this study, QDs were functionalized with bovine serum albumin (BSA) via a chemical linker. Anti-human immunoglobulin antibodies were oxidized by sodium periodate to create reactive aldehyde groups for a spontaneous reaction with the amine groups of BSA-modified QDs. An antibody-labeled QD bioconjugate was characterized using agarose gel electrophoresis, dynamic light scattering, and zeta potential. Using fluorescence spectroscopy, we found that the fluorescence of QDs was retained after multiple conjugation steps. The cell-labeling function of the QD bioconjugate was confirmed using an image analyzer and confocal microscopy. The QD bioconjugate specifically targeted human immunoglobulin on the membrane surface of recombinant cells. In addition, the QD bioconjugate applied in fluorometric immunoassay was effective for the quantitative analysis of human immunoglobulin in an enzyme-linked immunosorbent assay. The developed QD bioconjugate may offer a promising platform to develop biocompatible tools to label cells and quantify antibodies in the immunoassay.

A layer-by-layer covalent strategy is developed including the modification of QDs using BSA as a stabilizing agent and then anti-human immunoglobulin antibody as a targeting moiety.     

Highly sensitive cadmium sulphide quantum dots as a fluorescent probe for estimation of doripenem in real human plasma: application to pharmacokinetic study

Thioglycolic acid-capped cadmium sulphide quantum dots (TGA-CdS QDs) have been synthesized and utilized as a fluorescent probe for the estimation of doripenem (DOR). Monitoring of DOR in different biological fluids is required to estimate the efficient dose to avoid bacterial infections and resistance. The investigated method is based on the measurement of fluorescence quenching of TGA-CdS QDs after the addition of DOR. The synthesized TGA-CdS QDs were characterized using transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, X-ray powder diffraction (XRD) and ZETA sizer. The TGA-CdS QDs showed unique photophysical properties with high quantum yield (0.32) using a comparison method with rhodamine B. Different experimental parameters affecting the synthesis process of the TGA-CdS QDs and their behavior with the studied drug DOR were examined and optimized. The values of the fluorescence quenching were linearly correlated to DOR concentration over the range of 10–500 ng mL⁻¹ with a good correlation coefficient of 0.9991. The proposed method showed higher sensitivity over several reported methods, with LOD reaching 2.0 ng mL⁻¹. The method was effectively applied for the estimation of DOR in human plasma and urine with good recovery results ranged from 95.16% to 99.51%. Furthermore, the stability of DOR in the human plasma was studied and a pharmacokinetic study of DOR in real human plasma was conducted.

Thioglycolic acid-capped cadmium sulphide quantum dots (TGA-CdS QDs) as a fluorescent sensor have been synthesized and utilized as a fluorescent probe for the estimation of doripenem (DOR) in human plasma.     

Multimodal optical studies of single and clustered colloidal quantum dots for the long-term optical property evaluation of quantum dot-based molecular imaging phantoms

Understanding the optical properties of clustered quantum dots (QDs) is essential to the design of QD-based optical phantoms for molecular imaging. Single and clustered core/shell colloidal QDs of dimers, trimers, and tetramers are self-assembled, separated, and preferentially collected using electrospray differential mobility analysis (ES-DMA) with electrostatic deposition. Multimodal optical characterization and analysis of their dynamical photoluminescence (PL) properties enables the long-term evaluation of the physicochemical and optical properties of QDs in a single or a clustered state. A multimodal time-correlated spectroscopic confocal microscope capable of simultaneously measuring the time evolution of PL intensity fluctuation, PL lifetime, and emission spectra reveals the long-term dynamic optical properties of interacting QDs in individual dimeric clusters of QDs. This new method will benefit research into the quantitative interpretation of fluorescence intensity and lifetime results in QD-based molecular imaging techniques. The process of photooxidation leads to coupling of the QDs in a dimer, leading to unique optical properties when compared to an isolated QD. These results guide the design and evaluation of QD-based phantom materials for the validation of the PL measurements for quantitative molecular imaging of biological samples labeled with QD probes.     

A review on I–III–VI ternary quantum dots for fluorescence detection of heavy metals ions in water: optical properties,synthesis and application

Heavy metal contamination remains a major threat to the environment. Evaluating the concentrations of heavy metals in water environments is a crucial step towards a viable treatment strategy. Non-cadmium photo-luminescent I–III–VI ternary QDs have attracted increasing attention due to their low toxicity and extraordinary optical properties, which have made them popular in biological applications. Recently, ternary I–III–VI-QDs have gained growing interest as fluorescent detectors of heavy metal ions in water. Here, we review the research progress of ternary I–III–VI QDs for the fluorescence detection of heavy metal ions in water. First, we summarize the optical properties and synthesis methodologies of ternary I–III–VI QDs. Then, we present various detection mechanisms involved in the fluorescence detection of heavy metal ions, which are mostly attributed to direct interaction between these unique QDs and the metal ions, seen in the form of fluorescence quenching and fluorescence enhancement. We also display the potential applications in environmental remediation such as water treatment and associated challenges of I–III–VI QDs in the fluorescence detection of Cu²⁺ and other metal ions.

Ternary I–III–VI quantum dots used in the fluorescence detection of heavy metals ions in water.     

量子点荧光免疫渗滤法定量检测血清C反应蛋白的研究

目的：对基于量子点荧光的免疫渗滤快速定量检测血清 C 反应蛋白（CRP）方法进行初步探索，旨在建立一种较好的快速定量检测方法。方法采用双抗夹心法原理在免疫渗滤板上建立自制量子点和量子点-抗体复合物快速免疫检测法，其结果在紫外光照射下进行荧光定性检测。采用激光器和荧光光谱仪相结合的方法，可对荧光检测结果进行定量分析。结果定性检测到 CRP 的最低浓度为0．156 mg/L；定量检测 CRP 浓度范围在0．1～100．0 mg/L 的样本，其检测荧光值与浓度有线性对应关系，线性拟合方程为：log（Y ）＝0．563log（X）＋4．570，r2＝0．958。结论荧光免疫渗透快速定量法可对血清 CRP 进行定量检测；量子点免疫标记技术平台具有开发新型免疫诊断试剂的潜力。     

Small-molecule fluorescent probes and their design

Small-molecule fluorescent probes have become powerful tools for using light to advance the study of cell biology, discover new drugs, detect environmental contaminants, and further the detection of cancer. These applications correlate with the expansion of the fluorescent probe research community – small in the late 20^th century, now a collection of more than a hundred research groups world-wide. This expansion required the entry of adventurous scientists from many other fields. This tutorial review introduces some important concepts related to fluorescent probe development. It is hoped that it will facilitate further expansion of the field by demystifying it.

Small-molecule fluorescent probes allow light to be used as a tool to advance the study of biology, discover new drugs, and further the detection of cancer. This tutorial review introduces important concepts related to fluorescent probe development.     

Near-IR fluorescence and reflectance confocal microscopy for imaging of quantum dots in mammalian skin

Understanding the skin penetration of nanoparticles (NPs) is an important concern due to the increasing presence of NPs in consumer products, including cosmetics. Technical challenges have slowed progress in evaluating skin barrier and NP factors that contribute to skin penetration risk. To limit sampling error and other problems associated with histological processing, many researchers are implementing whole tissue confocal or multiphoton microscopies. This work introduces a fluorescence and reflectance confocal microscopy system that utilizes near-IR excitation and emission to detect near-IR lead sulfide quantum dots (QDs) through ex vivo human epidermis. We provide a detailed prediction and experimental analysis of QD detection sensitivity and demonstrate detection of QD skin penetration in a barrier disrupted model. The unique properties of near-IR lead-based QDs will enable future studies that examine the impact of further barrier-disrupting agents on skin penetration of QDs and elucidate mechanistic insight into QD tissue interactions at the cellular level.