石墨烯的合成与应用

论述了石墨烯非凡的物理及电学性质,包括电子输运-零质量的狄拉克-费米子行为,量子霍耳效应,最小量子电导率,量子干涉效应的强烈抑制等;石墨烯的机械和化学制备方法和石墨烯在纳电子器件方面、计算机芯片取代硅、制造最快的碳晶体管、减少噪声方面和潜在的储氢材料领域等方面的应用.     

量子点敏化太阳电池敏化剂的研究

量子点(QDs)的结构和组成决定了量子点敏化太阳电池(QDSSCs)光生电荷的产生、分离、传输及其光电转换效率。本文综述了近年来不同结构和组成的QDs作为敏化剂对QDSSCs效率的影响。     

信息功能材料的研究现状和发展趋势

介绍了国内外信息功能材料目前的研发水平、器件应用概况和发展趋势,主要介绍了半导体材料,也涉及到信息存储材料、有机光电子材料和人工晶体材料等。     

金属溴化物钙钛矿量子点的墨水法合成及其发光调控

采用墨水法,以溴化铯、溴化铅为源,以油酸为配体,在甲苯体系中室温下空气中快速合成Cs PbBr3钙钛矿量子点。该方法操作简单,能耗较低,而且能够通过控制配体的量,实现对钙钛矿量子点尺度的控制,当配体量增大时,量子点的尺寸由～12 nm减小到～5 nm。在反应过程中,配体的螯合阻止了量子点的进一步生长,同时,通过对样品的光致发光特性测量发现,较小的CsPbBr_3钙钛矿量子点的光发射峰在490 nm,大尺寸量子点的发光峰在515 nm,小尺寸量子点的荧光发射发生了蓝移,验证了小尺寸量子点的量子限域效应。因此,该方法不仅可以方便、快捷地应用于金属卤化物钙钛矿量子点的制备,而且能够调控量子点的光发射。     

核壳式CdSe/ZnS量子点对邻苯二甲酸二丁酯的快速高灵敏荧光测定

用水热反应法制备了核壳式CdSe/ZnS量子点并用透射电镜进行形貌表征,将该量子点作为荧光探针,基于邻苯二甲酸二丁酯(DBP)的荧光增强效应,建立了一种快速测定DBP的方法。在最优条件(pH7.0,反应时间15 min,水作溶剂)下,DBP对CdSe/ZnS量子点的荧光增强作用最显著,在1.0～20.0μg/L范围内荧光信号强度与DBP浓度的对数呈线性关系,检出限为0.21μg/L,相关系数R²为0.99。该方法可用于白酒中DBP的含量测定,与现有标准方法GC-MS比较,具有高的检测灵敏度和准确性。     

量子流体氦黏度的分子动力学模拟

采用分子动力学模拟了量子流体在微通道内的剪切应力与速度分布。利用经典流体力学理论中剪切应力和速度分布之间的关系式,得到了量子流体氦在不同温度和密度条件下的动力粘度。模拟针对LJ模型和带有量子效应校正的QFH模型展开,分别采用大小不等的两套分子体系,获得了氦在超临界区和液体区内若干状态点的动力粘度。采用量子效应校正后的模拟过程将会占用大量的计算资源,因此一般的个人计算机不可能在短时间内实现其大量状态点的计算。     

数字油田建设中的量子神经网络研究

通过文献调研,了解数字油田的特征、应用以及未来发展与量子神经网络的概念、模型及应用。通过量子神经网络在石油领域所取得的交叉性研究成果,探讨量子神经网络在数字油田建设中的可能性。     

中国科大实现室温下二维材料固态自旋色心的相干操控

中国科学技术大学郭光灿院士团队李传锋、唐建顺、王轶韬等人与合作者合作,发现六方氮化硼(hBN)中一类超亮的具有优异光学性质和自旋性质的单自旋色心,并实现了对其在室温下的相干操控。研究成果日前发表在国际期刊《自然·通讯》上。固态自旋色心是实现量子信息技术的重要体系之一,比较著名的是金刚石中的NV色心,目前已经在量子计算、量子传感、量子网络等方面取得重要进展。近年来,宽禁带材料hBN被证明是自旋色心的优秀宿主,由于其二维特性,在低维量子器件制备、近场传感探测等方面相对于三维体材料有特殊优势,hBN中的自旋色心已成为当前的一个研究热点。     

量子点标记DNA的应用与进展

量子点作为新型纳米微晶,在生物标记方面有着无与伦比的应用前景.综述了量子点标记DNA的方法,以及量子点-DNA探针在检测DNA、蛋白质及DNA之间相互作用等领域的最新应用和进展.并对DNA探针在未来的应用进行了展望.     

金刚石色心与量子信息通信

金刚石具有许多不同的缺陷,但有两类金刚石缺陷量子位已成为通信应用的主要候选对象:氮空位中心(NV)和硅空位中心(SiV)。NV和SiV都是通过从金刚石晶格中去除两个相邻的碳原子,并分别用单个氮原子或硅原子代替它们而形成的。量子中继器的工作原理是将编码在光子上的信息传输到固定的存储量子位上,信息可以在其中存储和校正。缺陷量子位,例如色心,是此操作的良好候选者,因为它们自然具有与光(其颜色的来源)的有效界面,并且因为子集可以访问长寿的“自旋”记忆。这种自旋可以被认为是包含在材料中每个电子、质子和中子中的微小磁铁。可以通过将量子位放置在磁场中来访问该自旋存储器,这样自旋沿着磁场的方向定向。然后通过自旋是指向磁场还是相反来定义存储器,这分别对应于1位或0位。当光从色心反射回来时,它可以翻转这个自旋量子位,在所谓的自旋光子界面中,使光和自旋记忆之间的信息传输成为可能。具有这种特性的色心——例如NV和SiV——是量子中继器的有用候选者。     

The formation mechanism of Cd–S–Se quantum dots with CdSe/CdS core–shell structure within silicate glass

The formation mechanism of Cd–S–Se quantum dots (QDs) with a CdS/CdSe core–shell structure within a silicate glass system was investigated by monitoring the change in the first excitonic absorption peak of CdSe, CdS, and Cd–S–Se QDs as a function of the heat-treatment (HT) duration. When a silicate glass containing QD formation components for CdSe or CdS single-phased QDs was heat-treated, CdSe QDs grew via Ostwald ripening, whereas CdS QDs hardly formed within the given silicate glass matrix. When the glass, including CdO, ZnSe, and ZnS, was utilized for the synthesis of Cd–S–Se QDs within the glass matrix, Cd–S–Se QDs were successfully formed and exhibited similar growth behavior to CdSe QDs during the initial stage of HT. The structural changes in the QD-embedded glasses during HT were also monitored by Raman spectroscopy and discussed, and a possible formation mechanism of CdSe/CdS core–shell-structured QDs within silicate glasses is suggested.     

Increased conductance of individual self-assembled GeSi quantum dots by inter-dot coupling studied by conductive atomic force microscopy

ABSTRACT: The conductive properties of individual self-assembled GeSi quantum dots (QDs) are investigated by conductive atomic force microscopy on single-layer (SL) and bilayer (BL) GeSi QDs with different dot densities at room temperature. By comparing their average currents, it is found that the BL and high-density QDs are more conductive than the SL and low-density QDs with similar sizes, respectively, indicating the existence of both vertical and lateral couplings between GeSi QDs at room temperature. On the other hand, the average current of the BL QDs increases much faster with the bias voltage than that of the SL QDs. Our results suggest that the QDs' conductive properties can be greatly regulated by the coupling effects and bias voltages, which are valuable for potential applications.     

CdTe量子点的纯化以及作为pH探针的研究

以巯基乙酸为稳定剂在水相中合成了CdTe量子点,并将合成的CdTe量子点进行表征、纯化。通过用0.05 mol.L-1PBS缓冲溶液调节不同的pH来考察量子点的荧光强度和pH的关系。研究发现,水溶性的CdTe量子点是pH敏感的,随着pH值的降低,量子点荧光强度的下降规律与溶液pH值呈现良好的线性关系。结果表明,CdTe量子点是一个令人满意的pH敏感的探针,有潜在的化学和生物传感能力。     

Quantum dot based turn-on fluorescent probes for anion sensing

The design of fluorescent probes for turn-on sensing of anions has been especially significant because it can effectively enhance sensing sensitivity by decreasing the background interference. In the present work, we have systematically studied the potential applications of fluorescent quantum dots (QDs) in turn-on anion sensing. The fluorescence of QDs are firstly quenched by three different mechanisms, i.e. fluorescence resonance energy transfer, electron transfer and surface states modulated fluorescence. The fluorescence of the pre-quenched QDs can then be recovered by various anions due to the modulating effects of added anions on the interaction between QDs and QDs, the interaction between QDs and quenchers, and the surface chemistry of the quenched QDs, respectively. The results described here indicate that turn-on sensing of various anions by QDs-based systems can be achieved by rationally choosing fluorescence modulating strategies, demonstrating the versatility of QDs in the corresponding applications.     

靶向壳聚糖基因载体与水溶性量子点的自组装

将透明质酸(HA)接枝到四种不同分子量的壳聚糖(CS)上,获得了靶向壳聚糖基因载体。将CS及接枝CS分别与水溶性量子点(QDs)自组装,研究发现,相对于纯QDs,CS/QDs复合物及接枝CS/QDs复合物的荧光强度均明显增强,荧光发射峰位发生红移。复合物呈核/壳结构,QDs被包裹在核内。和CS/QDs复合物相比,接枝CS/QDs复合物的尺寸更小,分布更为均一。     

Cytotoxic Effects of CdSe Quantum Dots on Maturation of Mouse Oocytes, Fertilization, and Fetal Development

Quantum dots (QDs) are useful novel luminescent markers, but their embryonic toxicity is yet to be fully established, particularly in oocyte maturation and sperm fertilization. Earlier experiments by our group show that CdSe-core QDs have cytotoxic effects on mouse blastocysts and are associated with defects in subsequent development. Here, we further investigate the influence of CdSe-core QDs on oocyte maturation, fertilization, and subsequent pre- and postimplantation development. CdSe-core QDs induced a significant reduction in the rates of oocyte maturation, fertilization, and in vitro embryo development, but not ZnS-coated CdSe QDs. Treatment of oocytes with 500 nM CdSe-core QDs during in vitro maturation (IVM) led to increased resorption of postimplantation embryos and decreased placental and fetal weights. To our knowledge, this is the first study to report the negative impact of CdSe-core QDs on mouse oocyte development. Moreover, surface modification of CdSe-core QDs with ZnS effectively prevented this cytotoxicity.     

谷氨酰胺为稳定剂制备硒化镉纳米晶及光谱性质研究

以谷氨酰胺(Gln)为稳定剂合成了硒化镉纳米晶,利用X-射线粉末衍射(XRD)和透射电镜(TEM)对纳米晶结构进行了表征,粒径约为20 nm。通过紫外-可见吸收光谱、激发光谱与发射光谱研究了纳米晶光谱特性。实验结果表明,反应温度过高、反应时间过长都会破坏谷氨酰胺(Gln)的稳定作用,使CdSe聚集,影响其荧光性质。而聚乙二醇(PEG)的加入会使纳米晶的荧光发射明显加强,而且发射峰峰形尖锐。     

Probing Antigen-Antibody Interaction Using Fluorescence Coupled Capillary Electrophoresis

In this report, the use of fluorescence detection coupled capillary electrophoresis (CE-FL) allowed us to fully characterize the antigen-antibody interaction. CE-FL allowed separation of unbound quantum dots (QDs) and ligand bound QDs and also revealed an ordered assembly of biomolecules on QDs. Further, we observed FRET from QDs donor to DyLight acceptor, which were covalently conjugated with human IgG and goat anti-human IgG, respectively. The immunocomplex was formed and the mutual affinity of the antigen and antibody brought QDs and DyLight close enough to allow FRET to occur. This novel CE-based technique can be easily extended to other FRET systems based on QDs and may have potential application in the detection of antibodies.     

The growth of CdSe quantum dots on a single wall carbon nanotubes template without organic solvent and surfactant

A conventional synthesis of Cadmium selenide (CdSe) quantum dots (QDs) usually employs toxic organic solvents, and the synthesized CdSe QDs must be modified for dispersion in an aqueous solution. This modification often limits the application of CdSe QDs in biomedical fields. In this study, a simple method was developed to synthesize CdSe QDs on single wall carbon nanotubes (SWCNTs) employing the SWCNTs as a template to prevent the aggregation of the CdSe QDs in an aqueous solution without the addition of any organic reagent.Our newly developed synthetic procedure included the formation of SWCNTs with carboxyl groups (SWCNT-COOHs) followed by mixing these with the precursors of Cd and Se to obtain SWCNT-CdSe QDs. The resulting SWCNT-CdSe QDs were analyzed using spectrophotometry, transmission electron microscopy (TEM) and X-ray diffraction (XRD).Results showed that CdSe nanocrystals with a zinc blend structure could be synthesized on the SWCNT-COOHs. The average crystal size of the synthesized CdSe QDs was approximately 3 nm. The blue-shift of CdSe QDs powerfully emitted light at 550 nm as compared to the bulk CdSe at 730 nm. These CdSe QDs were synthesized in an aqueous environment without using toxic surfactants and are expected to have great potential as bio-labeling contrast agents in the future.     

Facile preparation of highly luminescent CdTe quantum dots within hyperbranched poly(amidoamine)s and their application in bio-imaging

A new strategy for facile preparation of highly luminescent CdTe quantum dots (QDs) within amine-terminated hyperbranched poly(amidoamine)s (HPAMAM) was proposed in this paper. CdTe precursors were first prepared by adding NaHTe to aqueous Cd²⁺ chelated by 3-mercaptopropionic sodium (MPA-Na), and then HPAMAM was introduced to stabilize the CdTe precursors. After microwave irradiation, highly fluorescent and stable CdTe QDs stabilized by MPA-Na and HPAMAM were obtained. The CdTe QDs showed a high quantum yield (QY) up to 58%. By preparing CdTe QDs within HPAMAM, the biocompatibility properties of HPAMAM and the optical, electrical properties of CdTe QDs can be combined, endowing the CdTe QDs with biocompatibility. The resulting CdTe QDs can be directly used in biomedical fields, and their potential application in bio-imaging was investigated.