首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
稀土发光材料相比于传统有机荧光染料在生物成像、分子检测和传感等领域具有独特的优势。目前,稀土发光生物探针主要以可见光发射为主,此类探针受限于组织穿透深度,应用范围较窄。具有较大组织穿透能力的近红外(NIR)稀土发光生物探针,由于其发光效率较低而少有报到。本工作合成了一种新型近红外发光的卟啉镱-铂配合物,TFPYb-Pt,表征并测试了该配合物的光物理性质。实验证实TFPYb-Pt具有较大的NIR发光效率(980/1 030 nm,Фem=0.37)和较长的NIR发光寿命(τ=49μs),表明该配合物可望被用于开发新型生物NIR发光探针。  相似文献   

2.
类卟啉稀土配合物对于小鼠腹水肝癌细胞光敏损伤的研究   总被引:7,自引:0,他引:7  
研究了类卟啉稀土配合物(以下简称PLM-Gd-A)对小鼠腹水肝癌细胞(AH)的光敏作用及AH细胞对PLM-Gd-A的摄取表明:PLM-Gd-A被AH细胞摄取的速度快,用MTT方法测定了细胞光敏存活曲线,杀伤细胞的能力与光照时间和光照强度以及PLM-Gd的浓度密切相关,用FADU方法和电镜观察结果证明:该光敏损伤细胞的靶主要是在细胞核;对于不同稀土离子配合物光敏能力比较表明:Gd>Eu>Sm;造成细  相似文献   

3.
稀土发光材料在荧光成像中的应用   总被引:1,自引:0,他引:1  
稀土发光材料由于具有荧光寿命长、发射峰半峰宽窄和Stokes位移大等发光性质,在生命科学研究的各个领域,包括荧光免疫分析、离子识别、蛋白质活性测定、核酸检测等,有着广泛而重要的应用前景.本文以稀土配合物、稀土掺杂上转换材料和长余辉材料为代表,就当前稀土发光材料的发光性质及其在生物成像标记方面的研究做一综述,并对稀土发光...  相似文献   

4.
类卟啉稀土配合物对于小鼠腹水肝癌细胞光敏损伤的研究   总被引:2,自引:0,他引:2  
研究了类卟啉稀土配合物(以下简称PLM—Gd—A)对小鼠腹水肝癌细胞(AH)的光敏作用及AH细胞对PLM一Gd—A的摄取表明:PLM-Gd-A被AH细胞摄取的速度快(大约10min可达到平衡),用MTT方法测定了细胞光敏存活曲线,杀伤细胞的能力与光照时间和光照强度以及PLM—Gd的浓度密切相关,用FADU方法和电镜观察结果证明:该光敏损伤细胞的靶主要是在细胞核;对于不同稀土离子配合物光敏能力比较表明:Gd>Eu>Sm;造成细胞死亡的原因包括1O2、在内的活性氧。  相似文献   

5.
稀土及其配合物在生物医药上的研究进展   总被引:2,自引:0,他引:2  
稀土属于化学周期表中镧系元素,具有独特生物活性,能与具有特定生理活性的配体形成稀土配合物。简要归纳了稀土配合物的种类及特点,并阐述了稀土及其配合物在细菌,真菌,癌细胞,正常细胞和病毒方面的生物效应,指出稀土及其配合物在生物医药领域方面有很大的应用前景。  相似文献   

6.
发光在品种选育中的应用   总被引:1,自引:0,他引:1  
本文介绍了利用生物品种的发光特征进行品种选育的原理和方法。不同品种其发光光谱应有不同的特征。如果能将这些特征和品种属性相联系,则可能为品种选育提供一个发光学指标。癌细胞可视为正常细胞的变种,癌症的荧光诊断,实质上是用发光的方法鉴别癌细胞或癌组织。因而,发光在品种选育中的方法,原则上也可用于癌的诊断  相似文献   

7.
汤锡珂 《生命世界》1992,19(4):33-35
稀土元素为金属元素,这类元素具有特殊的电子结构,有多样的物理化学特性,因而使它们具有广泛的用途,例如石油裂化、炼钢、玻璃陶瓷和电视等工业均需应用稀土。稀土不但应用于工业,而且还应用于农业,本文就我国稀土农用及其研究情况作一简介。  相似文献   

8.
近红外光谱技术在烟草行业中的应用进展   总被引:4,自引:0,他引:4  
介绍了近红外光谱分析技术在烟草常规化学成分分析、烟气分析、卷烟配方设计、不同产地模式识别和真假烟鉴别等方面的应用,认为近红外光谱分析技术在烟草行业中正扮演着越来越重要的角色,而且具有十分广阔的应用前景.  相似文献   

9.
生物医学光子学的发展,总是伴随并促进着光子学新技术的发展。光学生物成像技术在癌症肿瘤诊断上有着巨大应用,尤其是具有优良发光特性的稀土离子掺杂的上转换发光纳米颗粒与光学生物成像技术的结合进一步发展了生物光子学在这一领域的应用。鉴于近几年很多人对上转换发光纳米粒子的大量研究,本文对其进行了系统的阐述,综述了稀土上转换发光纳米粒子的光学特异性、发光原理及其在光学成像中不可替代的优势;描述了上转换纳米粒子的化学组成,介绍了几种基本的合成方法,重点说明了水热合成法和热分解法,并从材料和光学两方面分析了生物应用的效率优化;总结了目前上转换材料在生物光子学中的几大应用,着重介绍了生物传感、细胞成像、动物成像、漫射光层析成像、光动力治疗、多模式成像六个方面的应用。本文在最后也对今后的研究进行了展望。  相似文献   

10.
电化学发光基因检测是把电化学发光的高灵敏性和传统分子生物学方法的稳定性结合于一体的一种新型的基因检测技术。与传统的基因检测方法相比,它具有无放射性危害、高灵敏度、操作简便等优点。近年被广泛地应用于核酸序列分析,基因突变分析,遗传病、转基因物种、病毒、微生物等的检测。本文概述了电化学发光的基本原理以及传统的基因检测技术,详细地介绍了电化学发光在当前基因检测中的应用现状,并对其前景作了展望。  相似文献   

11.
Lanthanide complexes exhibit interesting spectroscopic properties yielding many applications as imaging probes, natural chirality amplifiers, and therapeutic agents. However, many properties are not fully understood yet. Therefore, we applied magnetic circular dichroism (MCD) spectroscopy, which provides enhanced information about the underlying electronic structure to a series of lanthanide compounds. The metals in the M3+ state included Y, La, Eu, Tb, Dy, Ho, Er, Tm, Yb, and Lu; the spectra were collected for selected tetraphenylporphin (TPP) and octaethylporphin (OEP) complexes in chloroform. While the MCD and UV‐VIS absorption spectra were dominated by the porphyrin signal, metal binding significantly modulated them. MCD spectroscopy was found to be better suited to discriminate between various species than absorption spectroscopy alone. The main features and trends in the lanthanide series observed in MCD and absorption spectra of the complexes could be interpreted at the Density Functional Theory (DFT) level, with effective core potentials on metal nuclei. The sum over state (SOS) method was used for simulation of the MCD intensities. The combination of the spectroscopy and quantum‐chemical computations is important for understanding the interactions of the metals with the organic compounds. Chirality 26:655–662, 2014. © 2014 Wiley Periodicals, Inc.  相似文献   

12.
Theoretical techniques have been developed and/or improved to predict the molecular structure of lanthanide complexes which were used to calculate their electronic properties, in particular, their electronic spectra and energy levels necessary to calculate the rates of energy transfer from the ligands to the metal ion. The molecular structure has been obtained by the SMLC/AM1 (Sparkle Model for the Calculation of Lanthanide Complexes – Austin Model 1) model where the lanthanide ion is simulated by a sparkle implemented into the AM1 Hamiltonian used to perform a HF-SCF (Hartree-Fock Self-Consistent Field) calculation. The previous implementation of the SMLC/AM1 model (sparkle/1) involving only two parameters has been generalized to be consistent with the AM1 Hamiltonian and the new model (sparkle/2) significantly improved the prediction of molecular structures of Eu(III) complexes. For the electronic spectra and energy level calculations of the lanthanide complexes the model replaces the metal ion by a point charge with the ligands held in their positions as determined by the SMLC/AM1 model, and uses a INDO/S-CI (intermediate neglect of differential overlap/spectroscopic-configuration interaction) model. A preliminary study of the solvent effects on the absorption spectra of the free ligand is also presented. For the ligand-lanthanide ion energy transfer Fermi's golden rule is used with the multipolar and exchange mechanisms being implemented and tested for several complexes. These theoretical techniques have been applied to several complexes yielding very good results when compared to experimental data as well as predictions for the molecular and electronic structures and the relative contributions of the mechanisms for the energy transfer rates. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

13.
Polyaminopolycarboxylate-based ligands are commonly used to chelate lanthanide ions, and the resulting complexes are useful as contrast agents for magnetic resonance imaging (MRI). Many commercially available ligands are especially useful because they contain functional groups that allow for fast, high-purity, and high-yielding conjugation to macromolecules and biomolecules via amine-reactive activated esters and isothiocyanate groups or thiol-reactive maleimides. While metalation of these ligands is considered common knowledge in the field of bioconjugation chemistry, subtle differences in metalation procedures must be taken into account when selecting metal starting materials. Furthermore, multiple options for purification and characterization exist, and selection of the most effective procedure partially depends on the selection of starting materials. These subtle differences are often neglected in published protocols. Here, our goal is to demonstrate common methods for metalation, purification, and characterization of lanthanide complexes that can be used as contrast agents for MRI (Figure 1). We expect that this publication will enable biomedical scientists to incorporate lanthanide complexation reactions into their repertoire of commonly used reactions by easing the selection of starting materials and purification methods.  相似文献   

14.
The fabrication of a low reabsorption emission loss, high efficient luminescent solar concentrator (LSC) is demonstrated by embedding near infrared (NIR) core/shell quantum dots (QDs) in a polymer matrix. An engineered Stokes shift in NIR core/shell PbS/CdS QDs is achieved via a cation exchange approach by varying the core size and shell thickness through the refined reaction parameters such as reaction time, temperature, precursor molar ratio, etc. The as‐synthesized core/shell QDs with high quantum yield (QY) and excellent chemical/photostability exhibit a large Stokes shift with respect to the bare PbS QDs due to the strong core‐to‐shell electrons leakage. The large‐area planar LSC based on core/shell QDs exhibits the highest value (6.1% with a geometric factor of 10) for optical efficiency compared to the bare NIR QD‐based LSCs and other reported NIR QD‐based LSCs. The suppression of emission loss and the broad absorption of PbS/CdS QDs offer a promising pathway to integrate LSCs and photovoltaic devices with good spectral matching, indicating that the proposed core/shell QDs are strong candidates for fabricating high efficiency semi‐transparent large‐area LSCs.  相似文献   

15.
16.
17.
18.
19.
目前,恶性肿瘤严重威胁人类健康和生命。临床上常用放疗法和化疗法治疗肿瘤,在一定程度上抑制肿瘤的生长和转移。但是,传统的化疗药物在给药过程中缺乏靶向性、副作用大,而且大多数化疗药物水溶性差,效果有限,高剂量的重复给药会导致耐药,单一模式的治疗策略效果不佳。因此通过构建靶向智能多功能纳米载药系统实现肿瘤精准诊断和治疗成为近年来的研究热点。卟啉金属有机骨架(MOFs)材料具有多孔性、大比表面积、表面可修饰等特性,有望成为良好的靶向刺激响应型药物载体。而且卟啉MOFs可以避免卟啉分子的自聚集以及在激发态的自猝灭,还具有卟啉分子的宽光谱响应范围,是一类具有广阔应用前景的固体光敏剂,因此卟啉MOFs近年来成为构建靶向智能多功能纳米载药系统的重要平台。本论文综述了近年来基于卟啉金属有机骨架材料的肿瘤治疗策略,特别是基于肿瘤内源性组分(pH、酶、氧化还原)和外源性物理信号(声、磁、光)刺激触发的多功能纳米平台用于肿瘤精准诊断和治疗的最新研究进展,并讨论了卟啉MOFs在未来肿瘤治疗中面临的挑战和机遇。  相似文献   

20.
酶放大镧系元素发光法测定碱性磷酸酶   总被引:1,自引:0,他引:1  
报告了应用酶放大镧系元素发光法测定碱性磷酸酶的方法.应用5-氟水杨酸磷酸酯作为酶底物,并对方法学中的多种因素进行了最佳比.用甲基硅油(I)改进了信/噪比的稳定性.方法的灵敏度为4 U/L.精密度为10%.精密度为10%的浓度范围是2.00~3.00×102 U/L.测量值的相对误差<10%.测定了血清中的碱性磷酸酶浓度,回收率为93%~95%.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号