量子点的制备及其在生物分析中的应用

文章针对近几年量子点(Quantum Dots,QDs)的发展趋势,综述了几种特征性的量子点制备方法,其中包括沉淀法,溶胶-凝胶法,水热法等,及其在生物医学、材料科学等方面的应用。通过运用比较的方法对量子点的优点及劣势进行了阐述。量子点又可称为半导体纳米微晶体(semiconductor nanocrystal),它是一种由Ⅱ-Ⅵ簇或Ⅲ-Ⅴ簇元素组成的稳定的、溶于水的、尺寸在1~100 nm之间的纳米晶粒。近年来,半导体量子点由于其独特性质越来越受到人们重视,其研究内容涉及物理、化学等多个学科,已经成为一门新兴的交叉学科。作为一种最新型的荧光材料,与传统的有机染料分子相比,量子点具有多种优势,其中最大优点在于有丰富的颜色,因此可以作为生物体系的荧光探针。这些优良的光学特性使量子点在生物化学,分子生物学,药品筛选等研究中有极广阔的应用前景。     

功能性量子点作为荧光探针测定环磷酸腺苷的含量

在温和的水溶液中合成水溶性的Mn2＋参杂的L-半胱氨酸包裹的ZnS量子点。该量子点在水溶液中能稳定存在,并与环磷酸腺苷有较强的亲和性。量子点与环磷酸腺苷相互作用产生荧光淬灭。在最优条件下,环磷酸腺苷在0.25×10-7~4.0×10-7mol.L-1浓度范围内与量子点有较好的线性关系,检出限为2.2×10-8mol.L-1。本文对常见干扰离子进行了考察,结果显示量子点对环磷酸腺苷有较强的选择性。该方法简便,快速,灵敏度高。     

量子点荧光探针用于汉坦病毒重组抗原的检测

目的应用量子点荧光探针对汉坦病毒（Hantavirus,HV）重组抗原进行检测。方法合成水溶性量子点荧光纳米颗粒,并在其表面修饰G蛋白和anti-HV抗体作为量子点荧光探针,对HV重组抗原进行检测并优化检测条件。结果量子点与抗体的最佳偶联条件：pH 6.0、反应时间2 h、抗体浓度为20μg/ml。用本方法检测HV重组抗原的最低检测值为5 ng/ml。结论该探针能有效的识别HV抗原,且操作简便快速,为HV重组抗原的检测和肾出血热综合征的诊断提供了新方法。     

量子点作为荧光探针在生物样品检测中的应用及进展

量子点(半导体纳米微晶体)作为一种新型荧光探针,在生物医学领域中的应用引起极大关注。本文主要概括了量子点的优势,及其在蛋白质、DNA、环磷酸腺苷、维生素C、大肠杆菌、金黄色葡萄球菌等生物样品检测中的应用,并对其应用前景进行了展望。     

新型纳米材料量子点在生物及药学领域的研究进展

量子点是一种新型荧光纳米材料,具有独特而优良的荧光性质.近年来量子点合成及应用引起研究者的广泛关注,研究内容涉及到物理、化学及药学等多个领域.本文简介了量子点的合成方法,并主要综述了量子点在生物成像、生物分析以及作为药物载体等方面的最新进展.     

盐酸法舒地尔的水溶性CdTe量子点荧光猝灭法测定

以谷胱甘肽(GSH)为稳定剂,在水溶液中制备稳定的CdTe纳米量子点.基于盐酸法舒地尔在pH 7.4的磷酸盐缓冲液中对该量子点的荧光具有较强的猝灭作用,建立了一种简便灵敏的测定盐酸法舒地尔的新方法.考察了缓冲体系、缓冲液pH、反应时间和量子点浓度等对盐酸法舒地尔测定的影响.结果表明,在0.1 mmol/L的磷酸盐缓冲液(pH 7.4)中,CdTe量子点浓度4 μg/ml,反应时间5 min,体系的相对荧光强度与盐酸法舒地尔浓度的线性关系良好,线性范围为0.525～78.7 ug/ml.     

近红外量子点在体内分析中的应用

半导体量子点作为新型高灵敏的荧光探针被广泛用于生物成像中。与传统可见光量子点相比,近红外量子点对深层组织和器官的检测具有更高的灵敏度和对比度,因而促进了活体动物实时荧光成像技术的发展并越来越受到人们的重视。总结介绍近红外量子点的光学特性及制备方法,及近红外量子点在活细胞标记、活体和组织成像包括淋巴结成像、血管造影与肿瘤定位等领域的研究进展及发展前景。     

L-半胱氨酸包覆的ZnS:Mn~(2+)水溶性的量子点荧光探针测定氟尿嘧啶的含量

目的:以绿色环保材料为基础,在温和的条件下合成了水溶性的L-半胱氨酸包覆的锰离子掺杂的硫化锌量子点(L-Cys/ZnS:Mn2+QDs),并以此为荧光探针建立了测定抗癌药物氟尿嘧啶(FU)的新方法。方法:研究了FU对L-Cys/ZnS:Mn2+QDs荧光的淬灭作用并阐述了可能的作用机理。实验还考察了缓冲液体系、pH、反应时间、量子点浓度等多种因素对测定FU的影响。结果:在磷酸盐(pH6.5)缓冲溶液中,L-Cys/ZnS:Mn2+QDs浓度为1.6×10-4mol.L-1时,FU在1.0~85μg.mL-1的浓度范围内对量子点的荧光强度有较强的猝灭作用,且体系的荧光强度变化与溶液中氟尿嘧啶的浓度符合斯特恩方程,线性方程为:Y=0.01059C+0.9757(r=0.9988);猝灭常数为1.377×103L.mol-1;检出限为0.38μg.mL-1。将方法应用于实际样品FU注射液的分析,获得满意结果,FU的加样回收率为99.2%~100.0%。结论:该法简便、快速、灵敏度高,可望将其作为一种新型的荧光标记物用于体内药物的示踪和测定。     

基于CdTe量子点和溴化乙锭-DNA共振能量转移的核酸检测

目的:基于CdTe量子点和溴化乙锭-DNA共振能量转移的核酸定量检测。方法:通过EDC交联法制备了量子点-核酸探针,该探针与溴化乙锭-DNA通过DNA的互补配对形成荧光共振能量转移模型,借助这个模型进行核酸的定量检测。结果:该法对核酸目标链检测的线性范围为0.025-0.188μmol/L,其相关系数为0.997,最低定量限为0.025μmol/L。结论:基于CdTe量子点和溴化乙锭-DNA共振能量转移模型可以用于DNA的定量检测。     

碳量子点的合成、表征及应用

对碳量子点的常用合成方法、表征手段及应用情况进行介绍。碳量子点是一种以碳元素为主体的新型荧光纳米材料,具有光学性能优良、细胞毒性低、生物相容性好、易于功能化和成本低廉等优点,在生物和医药领域具有广阔的开发前景。     

Degraded and undegraded carrageenans and experimental gastric and duodenal ulceration

The prevention of histamine-induced gastric and duodenal ulceration in the guinea-pig has been examined using a series of undegraded and degraded carrageenans. Undegraded carrageenans were active at lower doses than degraded carrageenans. The high viscosity of the undegraded carrageenans in solution prevented their use in larger doses. Degradation of carrageenan without serious loss of sulphate, gives a product which allows the dose to be increased to an extent that its effect more than offsets the slight loss in activity caused by the degradation. No single feature of carrageenan structure can be related to anti-ulcer activity although degradation, and hence reduction of molecular size, generally reduces activity. Sulphate contents over 30% have little apparent effect on activity; κ-carrageenans were not consistently different in anti-ulcer activity from Λ-carrageenans. This contrasts with the antipeptic activity of carrageenans where κ-carrageenans are less active than their Λ-counter-parts. As with antipeptic activity, the degree of anti-ulcer activity is probably determined by a combination of structural features which includes molecular size and polyanionic properties.     

Affective and Anxiety Disorders and Alcohol and Drug Dependence:

Depression and anxiety frequently coexist in patients with substance use disorders. This clinically-oriented article examiens the relationship between these conditions and emphasizes data showing that substances of abuse can cause signs and symptoms of both depression and anxiety. These substance-related syndromes appear to have a different course and prognosis than uncomplicated, independent anxiety and major depressive disorders, and clinicians should consider the role of alcohol and other drugs in all patients presenting with these complaints. The authors will also outline an approach for diagnosing and managing patients with the combination of a substance use and depressive or anxiety disorder.     

Alcohol and Substance Use and Abuse in Women and Children

No abstract available for this article.     

Glucosidase and fucosidase inhibitors and Advances in nucleosides and nucleotides.

The American Chemical Society Symposium "Glucosidase and fucosidase inhibitors" took place on 1 April 1998 and was organized by Professors Zbigniew J Witczak (UConn, School of Pharmacy, CT, USA), Kuniaki Tatsuta (Waseda University, Tokyo, Japan) and Waldemar Priebe, MD (Anderson Cancer Center, University of Texas, USA). Professor Witczak provided introductory remarks including the status of existing glucosidase inhibitors, and chaired the morning session, which consisted of six lectures. The symposium was well received, and was particularly attractive for those interested in networking, as attendance was about sixty. In addition, some participants and attendees presented posters on the subject during the regular poster session organized by the Division of Carbohydrate Chemistry.