25-原子金纳米球和纳米棒催化性能的比较(英文)

The catalytic properties of two nanocluster catalysts with atomically precisely known structures,icosahedral two-shelled Au25(SC2H4Ph) 18 nanospheres and biicosahedral Au25(PPh3) 10(SC2H4Ph) 5Cl2 nanorods,were compared. Their catalytic performance in the two reactions of the selective oxidation of styrene and chemoselective hydrogenation of α,β-unsaturated benzalacetone was investigated. The catalytic activities of icosahedral Au25(SC2H4Ph) 18 nanospheres were superior to those of the bi-icosahedral Au25(PP...     

金纳米棒@碳中空胶囊的制备及催化性能

以聚吡咯为碳壳前驱体制备了金纳米棒镶嵌于碳壳内的中空胶囊.先合成羧基修饰的聚苯乙烯微球和十六烷基三甲基溴化铵稳定的金纳米棒; 再利用二者之间的静电力将金纳米棒组装在聚苯乙烯微球表面; 最后, 通过氧化聚合将聚吡咯壳包覆在聚苯乙烯@金纳米棒复合物的表面.在氮气保护下经高温煅烧, 聚吡咯壳被碳化为碳壳的同时聚苯乙烯微球分解, 从而制得金纳米棒@碳中空胶囊.在煅烧过程中, 由于碳壳的保护, 金纳米棒很好地保持了“棒状”形貌.通过调节吡咯单体的浓度, 可以控制聚吡咯壳和碳壳的厚度.金纳米棒@碳中空胶囊在以NaBH₄为还原剂还原亚甲基蓝的反应中表现出良好的催化活性.     

聚乙二醇-金纳米棒介导的近红外光热抑菌作用

种子生长法合成纵向表面等离子体共振吸收峰为785 nm的金纳米棒,并对其表面进行聚乙二醇(PEG)修饰,研究了表面修饰PEG的金纳米棒(polyethylene glycol modified gold nanorods,PEG-GNR)的光热转化效应,并测试了其细胞毒性.以革兰氏阳性菌金黄色葡萄球菌、蜡状芽孢杆菌,革兰氏阴性菌大肠埃希氏菌及铜绿假单胞菌为细菌模型,详细研究了PEG-GNR在808 nm波长近红外激光照射下金纳米棒浓度和照射功率对抑菌效果的影响.结果表明,PEG-GNR对革兰氏阳性菌和革兰氏阴性菌在近红外照射下均有较好的抑菌效果,并且抑菌效果与金纳米棒的浓度和照射功率有着密切的关系;结合荧光显微镜和透射电子显微镜对细菌坏死状况的观察,初步证实细菌对PEG-GNR有效吸收是近红外光热杀菌的关键因素.     

聚乙二醇-金纳米棒介导的近红外光热抑菌作用

种子生长法合成纵向表面等离子体共振吸收峰为785 nm的金纳米棒,并对其表面进行聚乙二醇(PEG)修饰,研究了表面修饰PEG的金纳米棒(polyethylene glycol modified gold nanorods,PEG-GNR)的光热转化效应,并测试了其细胞毒性。以革兰氏阳性菌金黄色葡萄球菌、蜡状芽孢杆菌,革兰氏阴性菌大肠埃希氏菌及铜绿假单胞菌为细菌模型,详细研究了PEG-GNR在808nm波长近红外激光照射下金纳米棒浓度和照射功率对抑菌效果的影响。结果表明,PEG-GNR对革兰氏阳性菌和革兰氏阴性菌在近红外照射下均有较好的抑菌效果,并且抑菌效果与金纳米棒的浓度和照射功率有着密切的关系;结合荧光显微镜和透射电子显微镜对细菌坏死状况的观察,初步证实细菌对PEG-GNR有效吸收是近红外光热杀菌的关键因素。     

刺激响应性共聚物修饰金纳米棒的制备及其抗肿瘤性能

以1-叔丁氧基羰基-2-丙烯酰肼(Boc-AH)、N-(3,4-二羟基苯乙基)丙烯酰胺(DA)和聚乙二醇甲醚丙烯酸酯(mPEGA)为单体,利用可逆加成-断裂链转移聚合法制备了嵌段共聚物聚丙烯酰肼-聚N-(3,4-二羟基苯乙基)丙烯酰胺-聚单甲氧基聚乙二醇丙烯酸酯(PAH-b-PAD-b-PmPEGA,缩写为HDP),该...     

内含Fe_3O_4和金纳米粒子的碳化微球的制备及其催化性能

通过蒸馏-沉淀聚合制备了丙烯酸-二乙烯苯共聚物微球,经离子交换吸附Fe2+离子,然后通过空气中加热、氩气气氛中高温碳化得到了含Fe3O4纳米粒子的多孔磁性碳化微球。在水介质中多孔磁性碳化微球吸附氯金酸,然后还原得到内含金纳米粒子的磁性碳化微球。以硼氢化钠还原对硝基苯酚生成对氨基苯酚反应为例,研究了内含金纳米粒子的磁性碳化微球的催化作用。结果表明,内含金纳米粒子的磁性碳化微球对该反应有很好的催化作用。通过外磁场很容易将磁性微球从反应液相中分离出来,微球重复使用10次后其催化活性基本未变。     

各向异性金纳米粒子的制备及其在催化中的应用

尽管有关金纳米粒子催化的研究工作很多,但其中大多数都是采用传统的浸渍法将金盐负载到载体上、共沉淀或沉积-沉淀法制得负载的纳米粒子,但这些方法并未吸收最新的纳米技术。最近,金催化剂的研究者开发了在胶态悬浮液中制取金属纳米粒子,然后进行固载,从而使得单金属和双金属催化剂的催化活性和形貌控制取得较大进展。另一方面,最近十年出现了金纳米粒子合成的高级控制技术,得到了许多各向异性的金纳米粒子,且很容易制得新的形貌,可以控制纳米粒子的表面原子配位数和光学特性(可调的等离子体带),这些都与催化密切相关。这些形貌包括纳米棒、纳米星、纳米花、树枝状纳米结构或多面体纳米粒子等。除了高度关注各向异性金纳米粒子的最新开发的制备方法和性质,本综述也清楚地总结了这些纳米粒子独特的催化性能,以及通过提供更高催化性能的金催化剂、控制暴露的活性位,以及热、电和光催化的鲁棒性和可调性,从而给多相催化领域带来令人惊奇的潜在变革。     

哑铃型磁金介孔硅复合微球的制备及磁/光热催化性能测定

以金纳米粒为种子采取外延氧化生长氧化铁的方式,制备了哑铃型磁金纳米复合材料(Au-Fe_3O_4);以十六烷基三甲基溴化铵(CTAB)和F127为双模板剂通过溶胶凝胶法进一步包覆了介孔二氧化硅层(Au-Fe_3O_4@mSiO_2)。所制备Au-Fe_3O_4纳米粒子呈哑铃型,单分散性较好,尺寸分布均一,粒径为12～15 nm。Au-Fe_3O_4@mSiO_2复合物磁热性能与浓度和外加磁场强度成正比;浓度为25 mg·mL~(-1)时,磁场电流从25.5 A增大到42.5 A,溶液升温速率从0.39℃·min~(-1)增大到0.76℃·min~(-1)。Au-Fe_3O_4@mSiO_2复合物光热性能与浓度和激光照射功率密度成正比;复合物浓度为25 mg·mL~(-1)时,功率密度从0.3 W·cm~(-2)增大到1.2 W·cm~(-2),溶液升温速率从0.69℃·min~(-1)增大到2℃·min~(-1)。相同浓度的复合物溶液,光热性能明显优于磁热性能。浓度为25 mg·mL~(-1)的AuFe_3O_4@mSiO_2复合物催化S-亚硝基谷胱甘肽(GSNO)释放NO的反应在60 min时达到持续稳定释放,释放量最大为9.743μmol·L~(-1)。     

无种子法纳米金棒的制备及其对肿瘤细胞光热治疗效应研究

采用简便快捷的无种子法一步完成了纳米金棒的制备. 通过改变实验条件可以调控纳米金棒的吸收峰从可见到近红外转移. 将巯基聚乙二醇（PEG-SH）置换金棒表面的十六烷基三甲基溴化铵（CTAB）分子,大大提高了金棒的生物相容性. 制备的纳米金棒在近红外（NIR）光照射下对肿瘤细胞有很好的杀伤效果.研究结果为纳米金棒用于抗肿瘤治疗提供了实验基础.     

无种子法纳米金棒的制备及其对肿瘤细胞光热治疗效应研究

采用简便快捷的无种子法一步完成了纳米金棒的制备.通过改变实验条件可以调控纳米金棒的吸收峰从可见到近红外转移.将巯基聚乙二醇(PEG-SH)置换金棒表面的十六烷基三甲基溴化铵(CTAB)分子,大大提高了金棒的生物相容性.制备的纳米金棒在近红外(NIR)光照射下对肿瘤细胞有很好的杀伤效果.研究结果为纳米金棒用于抗肿瘤治疗提供了实验基础.     

基于金纳米棒的生物检测、细胞成像和癌症的光热治疗

由于金纳米棒颗粒独特的可调的表面等离子共振特性,使得金纳米棒颗粒在纳米复合材料和功能化纳米器件的构建、纳米生物技术、生物医学等领域具有广泛而重要的应用前景。本文综述了金纳米棒颗粒的生物检测、细胞成像和癌症的光热治疗方面的最新研究进展,并介绍了金纳米棒颗粒的光学性质和金纳米棒颗粒和几种主要的表面修饰方法,对金纳米棒颗粒在生物应用过程中存在的主要问题进行了讨论。     

Advances and Prospects of Gold Nanorods

With the development of nanotechnology, many novel nanomaterials with unique properties such as magnetic, electronics, and photonics are increasingly being exploited. Gold nanorods, which are rod‐shaped nanomaterials, show powerful potential in biological/biomedical fields, especially photothermal therapy, biosensing, imaging, and gene delivery for the treatment of cancer. Many scientific groups have shown strong interests in gold nanorods and have attempted to push them towards possible clinical applications. However, owing to the quantum‐size effects of nanomaterials, people have also raised some concerns about the potential toxicity hazards. Therefore, it is becoming urgent to study and exploit the biological effects of gold nanorods for benefit in the near future.     

适体功能化的金纳米棒用于癌症靶向治疗的研究进展

金纳米棒(gold nanorods,GNRs)具有特殊的光学性质、较大的比表面积、出色的光热转换性能、表面易修饰等特点,在药物递送、光疗、生物成像和化学传感等领域应用十分广泛。适体是短的单链DNA或RNA片段,可特异性识别癌细胞或其表面的膜蛋白。近年来,适体功能化的GNRs在癌症靶向治疗领域显示出良好的应用前景。根据GNRs对癌症作用机制的差异,本文从光热疗法、光动力疗法、化疗和联合疗法4个方面总结了适体功能化的GNRs在癌症靶向治疗中的最新进展,并对该领域面临的主要挑战和发展趋势进行了探讨与展望。     

Deep‐Level Defect Enhanced Photothermal Performance of Bismuth Sulfide–Gold Heterojunction Nanorods for Photothermal Therapy of Cancer Guided by Computed Tomography Imaging

Bismuth sulfide (Bi₂S₃) nanomaterials are emerging as a promising theranostic platform for computed tomography imaging and photothermal therapy of cancer. Herein, the photothermal properties of Bi₂S₃ nanorods (NRs) were unveiled to intensely correlate to their intrinsic deep‐level defects (DLDs) that potentially could work as electron–hole nonradiative recombination centers to promote phonon production, ultimately leading to photothermal performance. Bi₂S₃‐Au heterojunction NRs were designed to hold more significant DLD properties, exhibiting more potent photothermal performance than Bi₂S₃ NRs. Under 808 nm laser irradiation, Bi₂S₃‐Au NRs could trigger higher cellular heat shock protein 70 expression and more apoptotic cells than Bi₂S₃ NRs, and caused severe cell death and tumor growth inhibition, showing great potential for photothermal therapy of cancer guided by computed tomography imaging.     

Luminescent Gold Nanorods To Enhance the Near-Infrared Emission of a Photosensitizer for Targeted Cancer Imaging and Dual Therapy: Experimental and Theoretical Approach

Strong plasmon absorption in the near-infrared (NIR) region renders gold nanorods (GNRs) amenable for biomedical applications, particularly for photothermal therapy. However, these nanostructures have not been explored for their imaging potential because of their weak emission profile. In this study, the weak fluorescence emission of GNRs is tuned to match that of the absorption of a photosensitizer (PS) molecule, and energy transfer from the GNR to PS enhances the emission profile of the GNR–PS combination. GNR complexes generally quench the fluorescence emission of nearby chromophores. However, herein, the complex retains or rather enhances the fluorescence through competition in energy transfer. Excitation-dependent energy transfer has been explained experimentally and theoretically by using DFT calculations, the CIE chromaticity diagram, and power spectrum. The final GNR–PS complex modified for tumor specificity serves as an excellent organ-specific theranostic probe for bioimaging and dual therapy both in vitro and in vivo. Principal component analysis designates photodynamic therapy a better candidate than that of photothermal therapy for long-term efficacy in vivo.