共查询到18条相似文献,搜索用时 93 毫秒
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量子点具有独特的光学性质, 在生物医学领域有着广泛的应用. Ag2Te作为Ⅰ-Ⅵ族量子点中的一员, 因具有生物毒性小和带隙窄等优势而备受关注, 但是目前直接合成水溶性Ag2Te量子点的方法较少, 而且可调节的荧光发射波长范围有限. 本文提出了一种合成荧光发射波长位于近红外Ⅱ区窗口的水溶性Ag2Te量子点的新方法. 该方法以硝酸银为银前体, N-乙酰-L-半胱氨酸为配体, 碲前体利用硼氢化钠还原亚碲酸钠得到, 反应条件温和(室温、 大气氛围)且不涉及有毒的有机试剂, 绿色环保. 通过进一步的阳离子处理钝化其表面缺陷, 可以得到尺寸均一的超小粒径水溶性Ag2Te量子点, 量子点的荧光发射波长为1160 nm, 量子产率为8.0% (以IR26染料为参照). 该方法所合成的Ag2Te量子点具有良好的生物相容性, 注入小鼠体内后能观察到明显的近红外荧光, 具有进一步生物应用的潜力. 相似文献
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在Ag2Se量子点表面生长宽禁带无机壳层以消除表面缺陷是提高其光致发光性能的有效方法.与Ag2Se相比,Ag2S带隙更宽,晶格常数相似,是Ag2Se量子点的理想壳层.然而,室温下精确制备Ag2Se@Ag2S核壳量子点仍然是一个挑战.分别采用胶体原子层沉积(c-ALD)法和一锅水相法在室温下合成了油溶性和水溶性的Ag2Se@Ag2S核壳量子点,并通过调控配体链长优化了水溶性Ag2Se@Ag2S核壳量子点近红外荧光性能.在c-ALD法中,以1-十二硫醇(DDT)包裹的Ag2Se量子点作为种子,以油胺(OAM)配位的Ag(OAM-Ag)和Na2S作为壳层前驱体,制备的油溶性Ag2Se@Ag2S核壳结构量子点暂无荧光发射,随后尝试通过高温退火但仍无法恢复其荧光发射能力.接着,在一锅水相法中,... 相似文献
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以巯基辛烷为表面配体, 通过调控Ag前体和Te前体的比例, 制备了第二近红外窗口荧光Ag2Te量子点. 采用透射电子显微镜(TEM)、 X射线衍射光谱(XRD)、 X射线光电子能谱(XPS)、 紫外-可见-近红外吸收光谱和荧光光谱等对产物进行了表征. 结果表明, 制得了粒径均一、 分散性好的油溶性Ag2Te量子点, 其最大荧光发射波长位于1320 nm, 荧光量子产率高达4.2%. 相似文献
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通过降低反应物中L-半胱氨酸(L-Cys)的比例,在水相快速合成了近红外CdTe量子点,使之对巯基化合物产生荧光响应. 并以此构建了一种基于表面配体缺失的CdTe近红外荧光量子点的巯基探针,为生物样品中的硫醇检测提供简便经济、高灵敏度和高选择性的新方法. 在其它多种氨基酸和生物液体中主要离子、分子共存的情况下,我们所制备的近红外量子点对L-Cys、同型半胱氨酸(Hcy)和谷胱甘肽(GSH)的荧光检测中显示了良好的选择性和灵敏度. 在血清和细胞提取液中,加标5.0 μmol·L-1硫醇的回收率均在90%~109%范围内. 该方法对L-Cys,Hcy和GSH的检出限(3s)分别为43,46和63 nmol·L-1. 相似文献
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构建了一种近红外二区成像探针,能对脑部病变进行近红外二区荧光成像.利用脑靶向肽Angiopep-2对Ag2S量子点进行修饰,Ag2S量子点和Angiopep-2多肽经EDC和NHS介导,通过氨基和羧基的缩合反应进行连接,采用琼脂糖电泳、动态光散射及透射电镜等方法对材料进行表征,并观察了材料对脑胶质瘤细胞U87MG的细胞毒性、材料在该细胞中的分布、摄取以及在实体瘤荷瘤鼠中的分布情况.结果显示,Ag2S量子点水合粒径约为6 nm,经肽修饰后粒径约为8 nm,表面zeta电位正电性增强,在琼脂糖电泳中,肽修饰后Ag2S迁移距离较Ag2S短,表明Angiopep-2多肽修饰到了量子点上.经过细胞实验发现,修饰后的Ag2S量子点在100 μg/mL以下没有细胞毒性,脑胶质瘤U87MG细胞对Angiopep-2多肽修饰的Ag2S较Ag2S具有更高的摄取.经过初步的实体瘤动物实验发现,Angiopep-2修饰的Ag2S能在皮下瘤模型中出现分布和聚集,说明修饰后的Ag2S量子点具有一定脑胶质瘤细胞的靶向性. 相似文献
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采用微波辅助加热法在水相中一步合成了梯度合金CdSeS量子点,荧光光谱和紫外吸收光谱表明,合成的CdSeS合金量子点具有较高的量子产率(30%左右)。X射线衍射分析和光电子能谱表征证明,合成的CdSeS量子点具有立方晶型,梯度合金结构,内部以CdSe为主,而外部主要以CdS为主;电子透射显微镜下观察到的量子点结晶度高,粒径小(仅2~3 nm),粒度分布均一。在此基础上探讨了所合成的合金量子点在氧化剂过氧化氢、不同的酸碱介质中及350 W氙灯的作用下其荧光光谱的稳定性。结果表明,该合金量子点的光稳定性与CdTe QDs相当,但具有更好的抗氧化性能和抗酸刻蚀性能,具有良好的应用前景。 相似文献
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以亚碲酸钠为碲源,硼氢化钠为还原剂,一步合成了巯基丁二酸(MSA)稳定的CdTe量子点.研究了反应液pH值、镉与碲的摩尔比及镉与巯基丁二酸的摩尔比等实验条件对CdTe量子点体系荧光量子产率的影响,并用荧光光谱、X射线粉末衍射及透射电子显微镜等对其进行了表征.结果表明,CdTe量子点具有闪锌矿结构,形貌呈球状;在pH=1... 相似文献
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AgInSe2 (AISe)量子点具有带隙小、斯托克斯位移大、荧光寿命长且不含重金属有毒元素等特性, 使其在生物医学领域具有重要研究价值. 同时, AISe量子点的光学性质对尺寸和组成具有强烈的依赖关系, 然而传统的直接合成法很难实现对AISe量子点形貌和组分的精准调控, 从而极大限制了其发光效率. 对此, 作者提出了温和条件(75 ℃)下以In2Se3:Zn2+量子点为模板, 离子交换法控制合成AISe近红外荧光量子点的策略, 所合成的AISe量子点很好地维持了In2Se3:Zn2+模板的形貌, 进一步通过系统调节Ag/In投料物质的量比控制离子交换程度, AISe量子点的实际Ag/In组分比实现了从0.26~1.09宽范围调节; 最高绝对量子产率可达42.5%, 这一数值远高于通过直接合成法所得到的AISe量子点. 通过稳态、瞬态和低温光谱等手段对不同组分AISe量子点的发光行为进行了系统的光谱学研究, 揭示了其发光机理. 另外, 利用AISe量子点高效的近红外发光和良好的生物安全性, 实现了基于AISe近红外量子点探针的肿瘤细胞靶向成像, 展示出AISe量子点在生物成像和疾病的早期诊疗等领域具有很好的应用潜力. 相似文献
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Peiqing Sun Kunlun Li Xiao Liu Jing Wang Dr. Xusheng Qiu Prof. Wei Wei Prof. Jing Zhao 《Angewandte Chemie (International ed. in English)》2023,62(14):e202300085
Pathogenic microorganisms in the environment are a great threat to global human health. The development of disinfection method with rapid and effective antibacterial properties is urgently needed. In this study, a biomimetic silver binding peptide AgBP2 was introduced to develop a facile synthesis of biocompatible Ag2S quantum dots (QDs). The AgBP2 capped Ag2S QDs exhibited excellent fluorescent emission in the second near-infrared (NIR-II) window, with physical stability and photostability in the aqueous phase. Under 808 nm NIR laser irradiation, AgBP2-Ag2S QDs can serve not only as a photothermal agent to realize NIR photothermal conversion but also as a photocatalyst to generate reactive oxygen species (ROS). The obtained AgBP2-Ag2S QDs achieved a highly effective disinfection efficacy of 99.06 % against Escherichia coli within 25 min of NIR irradiation, which was ascribed to the synergistic effects of photogenerated ROS during photocatalysis and hyperthermia. Our work demonstrated a promising strategy for efficient bacterial disinfection. 相似文献
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Thiolate‐Mediated Photoinduced Synthesis of Ultrafine Ag2S Quantum Dots from Silver Nanoparticles 下载免费PDF全文
Yitao Cao Dr. Wei Geng Run Shi Dr. Lu Shang Prof. Geoffrey I. N. Waterhouse Prof. Limin Liu Prof. Li‐Zhu Wu Prof. Chen‐Ho Tung Prof. Yadong Yin Prof. Tierui Zhang 《Angewandte Chemie (International ed. in English)》2016,55(48):14952-14957
Photoinduced syntheses offer significant advantages over conventional thermal strategies, including improved control over reaction kinetics and low synthesis temperatures, affording nanoparticles with nontrivial and thermodynamically unstable structures. However, the photoinduced syntheses of non‐metallic nanocrystalline products (such as metal sulfides) have not yet been reported. Herein, we demonstrate the first photoinduced synthesis of ultrafine (sub‐2 nm) Ag2S quantum dots (QDs) from Ag nanoparticles at 10 °C. By thorough investigation of the mechanism for the transformation, a fundamental link was established between the intrinsic structures of the molecular intermediates and the final Ag2S products. Our results confirm the viability of low‐temperature photochemical approaches in metal sulfide synthesis, and demonstrate a new rule which could be followed in it. 相似文献
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水溶性荧光CdSe量子点的合成及其在指纹显现中的应用 总被引:4,自引:0,他引:4
Water-soluble fluorescent CdSe quantum dots(QDs) were synthesized by using Se、Na2SO3 and CdCl2 as precursors and mercaptoacetic acid(TGA) as modifier. The effects of refluxing time and initial pH values of the reaction on the particle size and fluorescence intensity of CdSe QDs were studied. The XRD、HRTEM and fluorescent spectroscopy were employed to characterize these samples. It is found that CdSe QDs with crystalline size of 2~3 nm are homogeneously distributed in the organic matrix. The maximum fluorescence absorption and emission peak of CdSe QDs solution are at 450 nm and 562 nm, respectively. The fingerprint details on the surface of smooth objects were clearly developed with CdSe QDs solution under irradiation of UV lights. 相似文献
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Frontispiece: Thiolate‐Mediated Photoinduced Synthesis of Ultrafine Ag2S Quantum Dots from Silver Nanoparticles 下载免费PDF全文
Yitao Cao Dr. Wei Geng Run Shi Dr. Lu Shang Prof. Geoffrey I. N. Waterhouse Prof. Limin Liu Prof. Li‐Zhu Wu Prof. Chen‐Ho Tung Prof. Yadong Yin Prof. Tierui Zhang 《Angewandte Chemie (International ed. in English)》2016,55(48)
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Wanbang Xu Sheng Liang Ronghui Xu Guoxin Zhang Fenghua Xu 《Journal of Dispersion Science and Technology》2013,34(7):953-957
An optimized synthesis route was applied for controlling the preparation of CdSe quantum dots (QDs) in an aqueous solution. Some key factors which influencing the properties of CdSe QDs, such as initial pH, stabilizers, ratio of precursor, etc. were investigated. The size, shape, crystal structure, and optical property of CdSe QDs were also characterized by TEM, XRD, UV-Vis, and fluorescence (FL) spectra. The result showed that high-quality cubic CdSe QDs with 3 nm were obtained. The experiments also confirmed that thioglycolic acid (TGA), under the conditions of weak acid, is a better stabilizer than others. The ratio of [Cd2+] to [SeSO3 2?] played an important role in the formation of CdSe QDs. The mechanisms about the influence factors were also presented. 相似文献
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