Ag2Se@Ag2S核壳量子点的室温合成及其近红外荧光性能优化

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,...     

CdSe/CdS/SiO2复合纳米球的制备及发光性能

采用两相法合成了CdSe/CdS核-壳结构的量子点, 用氨水催化水解正硅酸乙酯制得复合结构的CdSe/CdS/SiO₂发光纳米球. 通过对量子点用量、氨水用量、反应时间及溶剂比例等实验条件的调节, 得到了单分散性较好, 尺寸在23~145 nm的复合发光纳米球. 利用紫外-可见吸收光谱和荧光发射光谱对其发光性能进行了研究, 同时利用透射电镜(TEM)观察复合纳米球的形貌. 结果表明, 复合发光纳米球样品的最高荧光量子产率可达8%.     

CdTe/CdSe核壳量子点的合成及其在指纹显现中的应用

以CdCl2和Te粉为原料,在水相中合成了CdTe量子点核;通过外延生长在CdTe量子点核上包覆一层CdSe量子点,得到具有良好荧光性能的CdTe/CdSe核壳量子点;采用X射线衍射仪、透射电镜、高分辨透射电镜分析了不同反应条件下合成的CdTe/CdSe核壳量子点的晶体结构和微观结构,并对其进行了荧光光谱等测试和指纹显现分析.结果表明,合成的CdTe和CdTe/CdSe量子点粒径在3～5nm之间,粒径分布窄,水分散性良好;可以通过控制反应时间和Te/Se比等得到在500～700nm显示荧光发射峰的CdTe/CdSe核壳量子点.此外,核壳CdTe/CdSe量子点可以有效地和指纹物质结合,可应用于对铝合金油潜指纹的鉴别.     

谷胱甘肽稳定水溶性CdTe/ZnTe量子点的制备与表征

用还原型谷胱甘肽(GSH)作为稳定剂, 合成了水溶性的CdTe/ZnTe核壳结构的半导体量子点. 考察了Zn/Cd反应物配比及GSH用量对CdTe/ZnTe量子点的性能影响. 用高分辨透射电子显微镜(HRTEM)和X射线粉末衍射(XRD)光谱对CdTe和CdTe/ZnTe的形貌和晶体结构进行了表征. 荧光光谱结果表明, 核壳结构的CdTe/ZnTe量子点比单一的CdTe量子点具有更高的荧光量子产率和更好的光活化性能.     

核/壳型CdTe@SiO2荧光纳米复合粒子的制备与表征

利用反相微乳法, 以巯基乙酸修饰的水溶性CdTe量子点为核, 包覆SiO₂, 制备得到核壳型CdTe@SiO₂荧光纳米复合粒子. 用紫外-可见(UV-vis)分光光度计, 荧光(PL)分光光度计, 红外(FT-IR)光谱仪, 透射电子显微镜(TEM)等分析测试手段, 对得到的荧光纳米复合粒子的性能进行表征, 结果表明: 得到的CdTe@SiO₂纳米复合粒子是核壳型结构, 由SiO₂壳层包覆多个量子点, 其大小均匀, 水溶性好, 有效地提高了量子点的稳定性, 大大增强了其抗光漂白性能, 为该材料的进一步生物应用打下了良好的基础.     

水溶性CdSe/CdS量子点的合成及其与牛血清蛋白的共轭作用

用巯基乙酸(TGA)作为稳定剂，合成了水溶性的CdSe和核壳结构的CdSe/CdS半导体量子点。吸收光谱和荧光光谱研究表明，核壳结构的CdSe/CdS半导体量子点比单一的CdSe量子点具有更优异的发光特性。用TEM、电子衍射(ED)和XPS分别表征了CdSe和CdSe/CdS纳米微粒的结构、形貌及分散性。红外光谱和核磁共振谱证实了巯基乙酸分子中的硫原子和氧原子与纳米微粒表面的金属离子发生了配位作用。在pH值为7.4的条件下，将合成的CdSe和CdSe/CdS量子点直接与牛血清白蛋白(BSA)相互作用。实验发现，两种量子点均对BSA的荧光产生较强的静态猝灭作用；而BSA对两种量子点的荧光则具有显著的荧光增敏作用，存在BSA时CdSe/CdS量子点的荧光增强是不存在BSA时体系荧光强度的3倍。     

水热法合成AgInS2/ZnS核/壳结构量子点及其荧光性能

以硫脲为硫源,采用谷胱甘肽(GSH)和柠檬酸钠(SC)为配体,通过水热法制备了水溶性AgInS2/ZnS(AIS/ZnS)核/壳结构量子点。系统研究了反应温度和配体用量对量子点的合成及其荧光性能的影响。采用X射线衍射(XRD)、透射电子显微镜(TEM)、紫外可见吸收光谱(UV-Vis)和光致发光光谱(PL)分别对量子点的物相、形貌和光学性能进行了表征,并考察了量子点的稳定性。实验结果表明,随着反应温度从70℃升高至90℃,促进了ZnS壳层的形成,有效地钝化了量子点的表面缺陷,获得的AIS/ZnS核/壳量子点的发光强度显著提高,发光峰位从600 nm蓝移至580 nm。配体的添加可以有效地平衡Zn^2+的化学反应活性,减缓ZnS壳层的生长,抑制核壳界面缺陷的形成,还能消除量子点的表面态,当nGSH/nZn^2+=2.0,nSC/nZn^2+=2.5时,AIS/ZnS量子点的荧光性能最佳。此外,AIS/ZnS核/壳结构量子点还具有优异的光学稳定性。     

磁性荧光纳米材料的制备与性能

采用表面活性剂3-氨丙基三乙氧基硅烷(APTES)修饰Fe₃O₄磁性纳米粒子, 经质子化后, Fe₃O₄磁性纳米粒子表面披覆大量的正电荷, 与表面带负电荷的巯基丙酸(MPA)修饰的核壳CdSe/CdS/ZnS量子点(QDs)通过强烈的静电作用而发生组装, 得到兼具磁性和荧光性能的磁性荧光纳米材料. 利用透射电子显微镜(TEM)、傅里叶变换红外光谱仪(FTIR)、X射线衍射仪(XRD)、荧光分光光度计和振动样品磁强计(VSM)等测试手段对磁性荧光纳米材料进行表征. 研究表明, 由两种粒子组装的核壳结构复合粒子拥有良好的磁性能和荧光性能.     

核壳结构ZnS∶Mn/ZnS量子点转光剂的制备及其性能研究

本文以巯基丙酸为稳定剂,采用共沉淀法合成ZnS∶Mn量子点,然后使用核外延法制备了具有将紫外光转红光性能的核壳结构ZnS∶Mn/ZnS量子点转光剂,并使用红外(IR)光谱,透射电镜(TEM)对其官能团结构和形貌进行了表征,采用紫外-可见吸收光谱和荧光光谱对其光学性能进行了研究。另外,考察了Mn的掺杂量,放置时间和不同pH的缓冲溶液对ZnS∶Mn/ZnS量子点荧光的影响。     

CdTe/Mn3 O4/SiO2荧光/磁共振双模成像纳米球的制备与表征

成功地制备了CdTe/Mn_3O_4/SiO_2核壳结构的荧光/磁共振成像双功能纳米球,并用透射电镜(TEM)、能谱分析(EDXA)、磁共振成像(MRI)、红外、荧光光谱等对其结构、磁共振成像和发光性能进行了表征。TEM照片显示所合成的纳米球具有明显的球形核壳结构。EDXA分析显示所制备的CdTe/Mn_3O_4/SiO_2纳米球表面只检测到Si和O元素,证明CdTe量子点和Mn_3O_4纳米立方体被成功地包被于二氧化硅纳米球之内。荧光发射光谱显示相对于CdTe量子点,CdTe/Mn_3O_4/SiO_2纳米球荧光发射光谱虽然发生了一定的蓝移,但是仍具有良好的荧光性能。MRI分析可知CdTe/Mn_3O_4/SiO_2纳米球的弛豫参数(r_1)为3.88 s~(-1)(mg·L~(-1))~(-1),说明所合成的CdTe/Mn_3O_4/SiO_2纳米球可用于T_1-加权磁共振成像。细胞毒性实验表明,当CdTe/Mn_3O_4/SiO_2溶液浓度达到300μg·mL~(-1)时,细胞活力仍可达到90%以上,表明此浓度对细胞的毒性作用较弱。     

Thiourea functionalized CdSe/CdS quantum dots as a fluorescent sensor for mercury ion detection

CdSe/CdS quantum dots(QDs) functionalized by thiourea(TU) were synthesized and used as a fluorescent sensor for mercury ion detection.The TU-functionalized QDs were prepared by bonding TU via electrostatic interaction to the core/shell CdSe/CdS QDs after capping with thioglycolic acid(TGA).It was observed that the fluorescence of the functionalized QDs was quenched upon the addition of Hg~(2+).The quantitative detection of Hg~(2+) with this fluorescent sensor could be conducted based on the linear relationship between the extent of quenching and the concentration of Hg~(2+) added in the range of1-300 μg L~(-1).A detection limit of 0.56 μg L~(-1) was achieved.The sensor showed superior selectivity for Hg~(2+) and was successfully applied to the determination of mercury in environmental samples with satisfactory results.     

CuInS_2量子点敏化太阳能电池中尺寸依赖的电子注入和光电性质

研究了CuInS2(CIS)量子点敏化太阳能电池(QDSSCs)的电子注入和器件性能与粒子尺寸之间的依赖关系.首先合成了不同尺寸的CuInS2量子点(QDs),制备了CuInS2量子点敏化的TiO2薄膜,并组装了量子点敏化太阳能电池.通过循环伏安法确定了CuInS2量子点的能级位置.采用时间分辨荧光光谱分析测量了CuInS2量子点到TiO2薄膜的电子转移速率和效率.结果发现,随着粒子尺寸从4.0 nm减小到2.5 nm,电子注入速率略微增加而电子注入效率减小,同时量子点敏化太阳能电池的开路电压基本不变,而光电转换效率、短路电流和填充因子(FF)均减小.上述研究结果表明量子点敏化太阳能电池性能的优化可以通过改变量子点的尺寸来实现.     

Synthesis of bovine serum albumin imprinted Mn:ZnS quantum dots

A novel bovine serum albumin（BSA） imprinted Mn-doped ZnS quantum dots（Mn:ZnS QDs） is firstly reported.The molecular imprinted polymer（MIP） functionalized Mn:ZnS QDs（Mn:ZnS@SiO₂@MIP） include the preparation of Mn:ZnS QDs,the coating of silica on the surface of Mn:ZnS QDs,and the functional polymerization by sol-gel reaction using 3-aminophenylboronic acid as the functional and cross-linking monomer in the presence of BSA（Mn:ZnS@SiO₂@MIP-BSA）,and then the elution of the imprinted BSA on the surface of Mn:ZnS@SiO₂ QDs.The results showed that the phosphorescence of Mn:ZnS@SiO₂@MIP is stronger quenched by BSA than that of non-imprinted one（Mn:ZnS@SiO₂@NIP）,indicating that the selectivity of the imprinted Mn:ZnS quantum dots toward BSA is superior to that of non-imprinted one.     

Synthesis of green CdSe/chitosan quantum dots using a polymer-assisted γ-radiation route

Chitosan-coated CdSe quantum dots (CdSe/CS QDs) were successfully synthesized in aqueous system through a γ-radiation route at room temperature under ambient pressure. The diameter of the resulting QDs was about 4 nm with narrow size distribution. The synthesized QDs exhibited an absorption peak at 460 nm and an emission peak at 535 nm. These QDs were cubic zinc blende CdSe in core structure and coated with chitosan on surface, with fine solubility in water.     

耦联剂辅助吸附法制备CuInS2量子点敏化太阳电池

分别以CuI 和InAc3 作为铜源和铟源, 十二硫醇(DDT)作为硫源, 采用直接加热法合成不同尺寸的CuInS₂ (CIS)量子点. 运用X射线衍射(XRD), 拉曼光谱(Raman), 高分辨率透射电镜(HRTEM), 紫外-可见(UVVis)吸收光谱表征其相结构、形貌及光学性能. 结果表明: 制备的CIS量子点为黄铜矿结构, 且随着时间的延长, 量子点逐渐长大, 吸收光谱的激子吸收峰逐渐红移, 表现出量子尺寸效应. 采用巯基乙酸为双功能耦联剂辅助吸附法制备CIS敏化的TiO₂薄膜. 通过衰减全反射红外光谱(ATR-FTIR)分析得出, 巯基乙酸上的羧基与TiO₂表面羟基连接, 另一端上的巯基代替长链的DDT与CIS 耦联, 将CIS 成功锚定在TiO₂表面. 该方法不仅操作简单, 而且容易实现CIS在TiO₂表面的吸附. 太阳电池光电性能测试表明, 粒径大小约为3.6 nm的CIS量子点表现出最优的吸附能力以及光电转换性能. 进一步采用连续离子吸附层法对CIS敏化的TiO₂薄膜进行CdS包覆, 光电转换性能大大提高, 其效率达到2.83%, 这主要源于CdS的包覆钝化了CIS 的表面缺陷, 有效地降低了电子复合.     

Measurement of interfacial toughness of metal film wire and polymer membrane through electricity induced buckling method

Non-toxic, environment-benign colloidal CuInS(2) (CIS) quantum dots (QDs) were synthesized through a facile noninjection, one-pot approach by reacting Cu and In precursors with dodecanethiol dissolved in 1-octadecence at 220 °C. The Cu:In precursor molar ratio was varied from 1:1 to 1:4 to intentionally generate Cu-deficient CIS QDs. Depending on the stoichiometry of the QDs, their emission peak wavelengths were tuned in red-deep red region. More Cu-deficient CIS QDs (Cu:In=1:4) were found to be more efficient than ones with Cu:In=1:1. After successive ZnS shell was overgrown on the surface of core QDs with Cu:In=1:4, the resulting core/shell QDs exhibited a highly efficient yellow emission with a quantum yield of ~50%. A substantially blue-shifted emission from the core/shell QDs versus core ones was described by suggesting an alternative recombination pathway that may be induced by the ZnS shell coating.     

超小荧光二硫化钨量子点的水热合成及细胞成像应用

以钨酸钠和半胱氨酸为原料, 采用水热法一步合成了具有超小粒径(约2 nm)的二硫化钨荧光量子点(WS₂ QDs). 利用透射电子显微镜(TEM)、 荧光光谱、 X射线光电子能谱(XPS)、 红外光谱(FTIR)和X射线衍射光谱(XRD)对其进行了表征, 并考察了其稳定性和细胞毒性. 结果表明, 制备的WS₂ QDs具有水溶性好、 稳定性高和细胞毒性低的优点. 将此WS₂ QDs用于人乳腺癌细胞(MCF-7)的成像, 并通过溶酶体荧光探针进行共定位, 发现此WS₂ QDs可能借助溶酶体进入细胞内.     

Effect of CdS Interlayer on Properties of CdTe Based Quantum Dots

Highly luminescent thioglycolic acid-capped CdTe-based core/shell quantum dots (QDs) were synthesized through encapsulating CdTe QDs in various inorganic shells including CdS, ZnS and CdZnS. CdTe/CdS core/shell QDs exhibited a significant redshift of emission peaks (a maximum emission peak of 652 nm for the core/shell QDs and 575 nm for CdTe cores) with increasing shell thickness. In contrast, the redshift of photoluminescence (PL) peak wavelength of CdTe/ZnS QDs was less than 15 nm. The PL peak wavelengths of the core/shell QDs depended strongly on core size and shell thickness. The PL quantum yields (QYs) of the CdTe/CdS core/shell QDs are up to 67 % while that of CdTe/ZnS core/shell QDs is 45 %. A composite CdZnS shell made CdTe cores a high PL QY up to 51 % and broadly adjusted PL spectra (a maximum PL peak wavelength of 664 nm). The epitaxial growth of the shell was confirmed by X-ray powder diffraction analysis and luminescence decay experiments. Because of high PL QYs, tunable PL spectra, and low toxicity from a ZnS surface layer, CdTe/CdZnS core/shell QDs will be great potential for bioapplications.     

CdTe/CdS核壳量子点与蛋白质荧光标记

利用连续离子层吸附技术合成了水溶性的CdTe／CdS核壳量子点．通过CdS壳层的包覆,量子点的量子效率由原来的15％（裸核）提高到38％（核壳）,这种核壳结构量子点的化学和光学性质具有更好的稳定性,可以用于生物标记．本文采取共价连接与静电吸附两种方法,实现了量子点的生物标记,电泳技术已证明,应用这种量子点成功地实现了对蛋白质分子的生物标记．通过对量子点与蛋白质偶联前后的荧光光谱分析,发现量子点与蛋白质作用后荧光增强是由于蛋白质对量子点进行了表面修饰,从而降低了表面缺陷引起的非辐射跃迁几率所致．通过共价连接量子点的荧光峰位红移,主要是由于偶极-偶极相互作用引起的;量子点与蛋白质静电吸附作用引起的荧光峰位蓝移主要起因于量子点表面电荷量的降低．     

Solvothermal synthesis of InP quantum dots and their enhanced luminescent efficiency by post-synthetic treatments

InP quantum dots (QDs) were solvothermally synthesized by using a greener phosphorus source of P(N(CH(3))(2))(3) instead of highly toxic P(TMS)(3) widely used, and subsequently subjected to a size-sorting processing. While as-grown QDs showed an undetectably low emission intensity, post-synthetic treatments such as photo-etching, photo-radiation, and photo-assisted ZnS shell coating gave rise to a substantial increase in emission efficiency due to the effective removal and passivation of surface states. The emission efficiency of the photo-etched QDs was further enhanced by a consecutive UV photo-radiation, attributable to the photo-oxidation at QD surface. Furthermore, a relatively thick ZnS shell on the surface of InP QDs that were surface-modified with hydrophilic ligands beforehand was photochemically generated in an aqueous solution at room temperature. The resulting InP/ZnS core/shell QDs, emitting from blue to red wavelengths, were more efficient than the above photo-treated InP QDs, and their luminescent properties (emission bandwidth and quantum yield) were comparable to those of InP QDs synthesized with P(TMS)(3). Structural, size, and compositional analyses on InP/ZnS QDs were also conducted to elucidate their core/shell structure.