碳量子点及其性能研究进展

碳量子点(Carbon Quantum Dots,CQDs)是一种新型的碳纳米材料,因其强的量子限域效应和稳定的荧光性能等一系列优异性能,吸引了化学、物理、材料和生物等各领域科学家的广泛关注。相比传统半导体金属量子点,CQDs还具备优异的低毒性和生物相容性,更拓宽了其在生物领域内的研究前景。本文简要地介绍了CQDs的制备方法,主要包括自上而下和自下而上两个方向。除此之外,本文综述了CQDs突出的物理化学性质和性能,包括CQDs的荧光性能、生物相容性和上转换效应,并对CQDs在其在生物成像上的应用进行了归纳。     

碳量子点纳米材料在铅卤钙钛矿太阳能电池中的应用研究进展

碳量子点（CQDs）是一类粒径较小,光学性能显著,且电荷传输性能优异的类半导体纳米材料,在钙钛矿太阳能电池的性能调控和改善中得到广泛的应用。从CQDs纳米材料的合成、性能及应用出发,综述了CQDs纳米材料在钙钛矿太阳能光电器件中电子传输层、钙钛矿光吸收层和空穴传输层等方面的应用进展,并展望了该类材料调控钙钛矿太阳能器件性能的发展趋势。     

由蚕砂制备的碳量子点在不同激发、pH、金属离子、温度及极性环境下的荧光性质研究

碳量子点作为一种新兴的荧光纳米材料,具有粒径分布均匀、光稳定性好、激发-发射波长可调控、表面可修饰等优良的性质,兼具低毒性、生物相容性好等优点,在分析检测和生物成像等领域展现出广阔的应用前景。而蚕砂是家蚕的干燥粪便,简单易得。利用蚕砂作为碳量子点制备原料,采用微波合成的方法制备得到了一种平均水合粒径为4.86 nm,含氮、硫修饰的碳量子点材料,可作为针对激发波长、pH、金属离子浓度、温度及溶剂极性的变化有着显著响应特性的碳量子点型荧光探针。该探针的荧光最大发射波长随激发波长或pH的增加而红移;荧光强度随温度或pH的降低而增加;随着金属离子,特别是铜离子的加入而逐渐降低,并随着EDTA络离子的加入而逐渐回复。在多种溶剂中该探针均具有较好的溶解度,当换用不同极性的溶剂时,随着溶剂极性的增加荧光发射波长逐渐红移。荧光性质随多重环境参数变化为该碳量子点在未来的生物检测和成像领域提供了广阔的应用前景。     

多色荧光碳点的溶剂回流合成及其复合高分子荧光薄膜的制备研究

以柠檬酸、尿素为前体,用甲苯、丁醇、乙醇、环丁砜等系列不同沸点的溶剂,通过反应条件温和简单的溶剂回流法一步合成了多色荧光碳点(CQDs).对所制备的碳点进行TEM、FT-IR和PL等表征,其中甲苯溶剂回流法制得的碳点荧光性能最优,具有最高的荧光强度和与聚甲基丙烯酸甲酯(PMMA)聚合物有较好的相容性.其荧光发射峰位于475 nm,颗粒粒径为3~6 nm;采用溶剂蒸发法制成具有红、黄、绿多色荧光的CQDs/PMMA复合荧光薄膜材料,可用于新型高分子聚合物薄膜荧光材料.     

机械研磨法制备荧光可调碳量子点

以有机小分子丙酮为前驱体,在碱性条件下,采用机械研磨法制备了蓝绿色荧光碳量子点(carbon quantumdots,CQDs-1),其荧光发射波长为500nm.加入氟化钾(或氯化钾)共同研磨后得到黄色荧光CQDs(CQDs-2,荧光发射波长为560nm),而加入溴化钾(或碘化钾)共同研磨得到红色荧光CQDs(CQDs-3,荧光发射波长为600 nm).通过紫外可见吸收光谱(UV-Vis)和荧光光谱(PL)测定了3种CQDs的光学性质;通过透射电子显微镜(TEM)、原子力显微镜(AFM)、X射线粉末衍射(XRD)和拉曼光谱(Raman)对制得的CQDs进行了形貌及结构表征,并推断了CQDs的形成机理.采用简单的机械研磨法制备的荧光可调CQDs具有低细胞毒性、良好的水溶性和生物兼容性,可进入肿瘤细胞用于细胞成像研究.     

碳量子点的制备及其在能源与环境领域应用进展

碳量子点(carbon quantum dots,CQDs)作为碳纳米材料家族的新成员引起了科学家广泛关注和极大的研究兴趣。 CQDs具有优良的光学特性、生物相容性及微弱的细胞毒性,在生物医药、生物传感器及光电子设备、环境及能源等领域中具有重要的应用。 本文从CQDs的制备方法出发,介绍了近年来发展的新型制备方法,讨论了其优缺点以及对所得CQDs在组成、结构和性质等方面的影响;基于CQDs独特的光学及电化学性能,重点介绍了CQDs在环境与能源领域的应用。 此外,对CQDs研究过程中存在的若干挑战进行了分析,提出了未来发展的一些思考和建议,为拓展CQDs多方面应用提供重要参考。     

CQDs/TNS复合光催化剂的制备及其可见光催化活性

以明胶为原料用水热法一步合成了碳量子点(CQDs),经过聚乙二醇表面修饰后,在乙醇溶液中与二氧化钛纳米片(TNS)复合形成了碳量子点高分散负载的CQDs/TNS复合光催化剂.对复合光催化剂进行了XRD、FT-IR、HRTEM和XPS表征,结果表明合成的碳量子点的平均粒径为4nm且具有较好的荧光性能.与纯TNS相比,CQDs/TNS复合光催化剂在可见光下对罗丹明B表现出很好的光催化降解活性.当CQDs/TNS复合光催化剂中CQDs含量为7.5%时光催化活性最好,并且在3次循环降解后活性仍保持不变.其优异的光催化活性来自于碳量子点的独特上转换荧光性能和二氧化钛纳米片高活性{001}晶面的共同作用.     

基于碳量子点的绿色合成及生物成像研究进展EI北大核心CSCD

碳量子点(CQDs)作为碳纳米材料家族成员之一,因其原材料广、成本低廉、较高的光致发光性能和良好的生物相容性,在研究和应用领域都受到了广泛的关注,是应用于生物成像的理想材料。CQDs的绿色合成是指采用环保型或无毒型原料,通过绿色合成方法,如炭化法、微波法、水热法等,合成具有荧光性能的无毒碳量子点,与传统的化学氧化、激光烧蚀、热解处理等方法相比,更加绿色环保、经济,其应用已成为研究热点。本文对碳量子点材料特性、绿色合成过程机理、绿色合成原料来源、合成方法,及其在癌细胞、微生物细胞等细胞成像方面的应用进行了综述,探讨了绿色合成CQDs的利弊问题,并提出了今后该研究领域面临的机遇与挑战。     

手性碳量子点的制备及其应用

手性碳量子点(CQDs)因兼具优异的荧光性质、良好的生物相容性、较低的毒性、易于功能化以及手性特征等,在催化、检测和生物医学等领域具有广阔的应用潜力。目前,通过一步法或两步法制备的手性CQDs,已应用于手性催化、手性检测、高尔基体靶向成像、选择性调控酶和蛋白活性、选择性调控细胞能量代谢和促进植物生长等领域。然而,手性CQDs的发展初露头角,需进一步完善可控合成工艺,制备高荧光量子产率的长波长手性CQDs,使其在生物医学等领域绽放异彩。     

碳量子点的生物毒性研究进展

作为一类新型碳纳米材料,碳量子点(CQDs)以其纳米尺寸效应、高水分散性、高荧光稳定性等优异特性及其低生产成本引起了科学界的广泛关注,成为国内外化学、材料学及生物科学等领域的研究热点.CQDs已被证实在生物传感、生物成像、药物载体、光催化等众多研究方向具有优异的应用价值.但是,也正是因为CQDs的广阔应用前景,尤其是在生物、医药及环境等领域的应用,增强了对其潜在的生物毒性进行研究评估的必要性.此外,在生产、使用、废弃和回收过程中,CQDs将不可避免地进入自然环境中,其高水分散性,其对自然环境,尤其是水环境的潜在生态影响需要得到重视.目前针对CQDs的生物毒性研究主要涉及对细胞、细菌、水生生物(藻类和鱼类)及陆生生物(大鼠、小鼠)等的影响.明确CQDs的生物毒性及其生态效应,对于正确理解和评估其环境风险,合理规划其使用和回收具有重要意义.本文阐述了这一领域的相关研究成果,并对其研究前景进行了分析和展望.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Cu0-catalysed 1,3-dipolar cycloadditions of α-amino acid derived N,N-cyclic azomethine imines to ynones

A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu⁰ as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than Cu^I in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).     

Synthesis and antioxidative/anti-inflammatory activity of novel fullerene–polyamine conjugates

(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C₆₀, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.