水溶性量子点CdSe／ZnS与蛋白质非特异性相互作用研究

研究了巯基乙酸修饰的水溶性量子点CdSe/ZnS与不同蛋白质的非特异性相互作用.发现牛血清白蛋白,卵清蛋白,血红蛋白和免疫球蛋白G均能增强巯基乙酸修饰的水溶性量子点CdSe/ZnS的荧光,而细胞色素C却使量子点的荧光猝灭;探讨了量子点与蛋白质作用导致荧光强度变化的原因.这些结果表明,在使用巯基乙酸修饰的水溶性CdSe/ZnS量子点作为生物探针时,必须要考虑不同蛋白质与量子点的非特异性相互作用.     

基于Hg~(2+)诱导DNA双链形成的汞离子检测试纸条研制

Hg2+能特异性地与2个胸腺嘧啶碱基(T)共价结合,介导T-T错配形成稳定的T-Hg2+-T结构。基于DNA修饰的纳米金探针研制了一种可检测水溶液中Hg2+浓度的层析试纸条。试纸条包含1条控制线和2条测试线,检测结果在5 min内可见,裸眼可见检测灵敏度为100 nmol/L。金标条阅读仪分析结果在10 nmol/L~10μmol/L范围内具有良好的线性关系,且对常见二价重金属离子Cu2+,Ni2+,Mg2+,Zn2+,Pb2+具有很好的选择性。该试纸条灵敏特异、快捷简单、操作方便、成本低廉,在环境监测和食品安全的现场快速检测中具有很好的应用前景。     

基于CdSe/ZnS核壳型量子点的高灵敏、快速细菌计数新方法的研究

以乙酰丙酮镉和硬脂酸锌为前驱体,合成了巯基丙酸修饰的CdSe/ZnS核壳型量子点(QDs)。并将其作为荧光探针,以金黄色葡萄球菌(S.aureus)为目标细菌,建立了一种高灵敏的、简单快速的细菌计数新方法,并借助荧光显微镜成功的进行成像探测研究。通过考察量子点浓度、孵育时间等因素的影响,确定了细菌定量检测的最佳条件。在最优化的实验条件下,体系的相对荧光强度随细菌数量的增加而增大。该方法的线性范围为102CFU/mL～106CFU/mL,检测限为102CFU/mL,线性回归方程为Y=427.586X-677.022(R=0.996 49)。本方法有效克服了传统的细菌计数方法存在的缺陷,具有较高的灵敏度和较好的重现性(实际样品检测的RSD=3.6%～8.1%),且操作简单、检测时间短、成本低,有很好的潜在应用价值。     

纳米硫化铅离子敏感材料的研究

该文采用均相沉淀法研制了硫化铅纳米粒子,对影响纳米硫化铅晶体形成的各种因素作了详细和系统的探讨,确定了合成纳米硫化铅的最佳工艺路线.在反应温度为1～10℃,络合剂EDTA与铅离子的浓度比为l,pb2+的初始浓度为0.075 mol/L,pH为3.0～3.5,Na2S溶液的滴加速度为2 mL/min及乙醇/水比为1/1的条件下,可得到平均粒径为30纳米的硫化铅颗粒.另外,利用纳米硫化铅作为活性物质,研制了纳米硫化铅PVC膜电极,电极在铅离子浓度1.0×10-1～1.0×10-4mol/L范围内呈线性响应,电极的检测下限为6.0×10-5mol/L.K+、Na+、Ca2+、Mg2+、Co2+、Cu2+、Fe2+、Mn2+、Fe3+、Al3+对电极无干扰,而Ag+、Zn2+、Cd2+、Hg2+对电极有一定的干扰.     

纳米磷光探针的超声制备及对铜离子的传感特征

以十二烷基硫酸钠作为乳化剂,在超声辐射作用下,磷光体1-溴-2-(3-丁烯基)萘和甲基丙烯酸发生共聚,形成生物兼容性的聚甲基丙烯酸基纳米磷光探针.粒径分布在(40±10)nm的探针大约85%.该纳米探针具有很好的水溶性,在溶解氧存在下,产生较强的磷光发射信号.铜离子对磷光信号具有较好的选择性猝灭作用,检出限在10-7 mol/L水平,可望用于生物条件下的铜离子传感.     

背景光辐照下SrAl2O4:(Eu2+,Dy3+)的力致发光性能实验研究

SrAl2O4:(Eu2+,Dy3+)作为一种力致发光材料,因其力致发光强度高而受到广泛的关注.但SrAl2O4:(Eu2+,Dy3+)力致发光强度随余辉衰减时间延长而减弱,这一特性阻碍了它在应力传感器中的实际应用.针对这一问题,本文采用小球下落冲击法,研究了背景光照射下SrAl2O4:(Eu2+,Dy3+)长余辉发光材料的力致发光特性.相比无背景光条件下的力致发光,采用的365 nm背景光持续辐照SrAl2O4:(Eu2+,Dy3+),可以使其力致发光强度不受余辉衰减时间影响,并能够提高力致发光强度及灵敏度.这一结果有助于推动SrAl2O4:(Eu2+,Dy3+)在冲击力传感领域的应用.     

亚微米铂粒子修饰电极液相色谱电化学检测巯基化合物的研究

该文研究了亚微米铂粒子修饰电极的制备方法.并将该修饰电极与高效液相色谱脉冲安培检测法(HPLC-PAD)联用,分别检测了半胱氨酸(L-Cys)、谷胱甘肽(GSH)和青霉胺(PEN)三种巯基化合物.结果表明该修饰电极对这三种巯基化合物有良好的催化氧化作用;由于PAD的周期性的阳极高电位和阴极低电位能很好地清洗和再活化电极表面,应用PAD方法能有效提高巯基化合物的电流响应.此外,结果还表明,L-cys、GSH和PEN的电流响应与其浓度呈现良好的线性关系,其检出限分别为1.1×10-8mol/L、1.8×10-7mol/L和3.8×10-7mol/L(S/N=3).与微渗析技术联用,该方法成功地用于大鼠脑中L-Cys和GSH的测定.这为电分析化学在临床医学、生理学等生命科学中的应用提供了新的手段.     

通过磷光寿命分布评价环状的单或双调节组分对环糊精诱导溴代芳烃磷光体系的影响

通过不同衰减组分的寿命差异和寿命分布评价十氢萘、环己烷和金刚烷单或双组分对环糊精诱导溴代芳烃磷光体系的影响.在金刚烷、环己烷和十氢萘存在下,探针9-BrP的平均磷光寿命分别为0.83、1.1和2.4ms,而体积较小的探针1-BrN的平均磷光寿命分别为5.9、7.8和9.2ms.两种探针的长寿命组分分布在62%到95%之间.相应于十氢萘+金刚烷、环己烷+金刚烷和环己烷+十氢萘组合的双调节组分体系,9-BrP的平均磷光寿命分别为2.28、1.70和1.81ms,均为双组分衰减,短寿命组分分布占优,大于55%;1-BrN的平均磷光寿命分别为5.83、7.37和7.82 ms,长寿命组分分布占绝对优势,大于93%.实验中发现过量有机溶剂将晶体颗粒和水包裹在气泡中形成稳定的泡沫体系(microparticles-water-in-bubbles,μ-PWB),诱导较强的磷光.在此μ-PWB体系,十氢萘或金刚烷+十氢萘组合条件下9-BrP磷光均为单组分衰减,环己烷或金刚烷+环己烷组合条件下9-BrP均为双组分衰减,短寿命组分分布占优,大于67%.     

基于CdSe/ZnS量子点荧光生物传感器构建与应用

设计了一种由CdSe/ZnS量子点和荧光染料Cy3(C31H37KN2O8S2)基于荧光共振能量转移(FRET)原理的生物传感器,并进行了该体系下不同浓度和不同pH溶液中荧光转移强度的实验。实验表明:CdSe/ZnS荧光半导体量子点作为供体对Cy3(C_(31)H_(37)KN_2O_8S_2)染料的荧光增强作用明显。在CdSe/ZnS量子点与Cy3的比例为1∶1.2时,荧光转移效率达到83.68%,对细胞外液p H值荧光变化敏感(pH=5.93～8.36)。此外,该生物传感器可以清楚地识别前列腺癌细胞。该实验结果对前列腺癌细胞的早期诊断和前列腺癌生物传感器的设计提供了一种新的方法。     

海胆球形锰酸锂修饰碳糊型锂离子选择电极的研究

建立了一种新的锂离子选择电极体系,以水热法的Mn O2为原料制备海胆球形的尖晶石锰酸锂,以其为活性载体,采用压片技术制备了锰酸锂-碳糊电极(LMO-CPE),该电极对Li+具有优良的电位响应特性。并探讨了响应机理,系统研究了电极组分配比、适用的p H值范围、检测下限、选择性系数等性能。实验结果表明:锰酸锂:乙炔黑:石蜡(质量分数比)=20∶50∶30时制备的LMO-CPE电极在1×10-5~1×10-1mol/L范围内出现能斯特响应,p H=10时的响应性能最好,响应时间15 s以下,斜率可达到67.17 m V/dec,检测下限7.76×10-6mol/L;采用混合溶液法测得Na+和K+选择性系数分别为1.02×10-3和1.97×10-3,Ca2+、Mg2+、Ba2+的选择性系数在10-5数量级以下,该类电极对于其他碱金属和碱土金属离子有好的选择性。     

Red light emission from hybrid organic/inorganic quantum dot AC light emitting displays

An alternating current electroluminescent display has been direct written onto a flexible plastic substrate. A hybrid layer of poly(2-methoxy,5(2-ethylhexyloxy)-p-phenylene vinylene) (MEH-PPV) and CdSe quantum dots (QDs) were used to convert the light emitted by electroluminescent ZnS phosphor into red light. The emission wavelength of the display is found to be directly related to the emission of CdSe quantum dots. The integration of QDs into thin film electroluminescent (TFEL) displays has the potential to enhance its color spectrum.     

Color tuning of indium phosphide quantum dots for cadmium‐free quantum dot light‐emitting devices with high efficiency and color saturation

Semiconductor quantum dots (QDs) promise facile color tuning and high color saturation in quantum‐dot light‐emitting devices (QD‐LEDs) by controlling nanoparticle size and size distribution. Here, we demonstrate how this promise can be practically realized for the cadmium‐free InP/ZnSe/ZnS multishell quantum dots. We developed a set of synthesis conditions and core/shell compositions that result in QDs with green, yellow, and red emission color. The QD‐LEDs employing these QDs show efficient electroluminescence (EL) with luminance up to 1800 cd/m² and efficiency up to 5.1 cd/ A . The color coordinates calculated from the EL spectra clearly demonstrate the outstanding color saturation as an outcome of the narrow particle size distribution. These results prove that the performance gap between cadmium‐free and cadmium‐based QDs in QD‐LEDs is shrinking rapidly.     

Effects of K and Na ions on the fluorescence of colloidal CdSe/CdS and CdSe/ZnS quantum dots

In this work we studied the effects of K⁺ and Na⁺ ions on fluorescence properties of the colloidal quantum dots (QDs). It was found that the fluorescence intensity was enhanced when low concentration of ions was introduced to QD solutions, while it became weakened when ion concentrations reached their physiological levels in many bio environments. Such fluorescence changes can be attributed to interactions between QD surface ligands and ions as well as the Coulomb potential of ions that displaces the wave functions of the electron and hole confined inside the QD. These results are important for understanding the influence of different biological environments, such as extracellular and intracellular compartments, on optical properties of colloidal QDs.     

Si基多层Ge量子点近红外光电探测器研制

采用超高真空化学气相沉积( UHV/CVD)技术在Si衬底上外延生长了PIN结构多层Ge量子点探测器材料。 PIN探测器结构由N型Si衬底,多层Ge量子点吸收区,和原位掺杂P型Si盖层构成,电极分别制作于N-Si和P-Si上,以获得好的欧姆接触。制备的Si基Ge量子点光电探测器具有较低的暗电流密度(-1 V偏压下为7.35×10-6 A/cm2),与Si相比,探测波长延伸到1.31μm波段。     

量子点的近红外调控研究进展概述

近红外荧光因其更好的组织穿透能力,更低的背景干扰,在超灵敏活体成像以及多光谱生物成像应用中具有明显优势。文章根据量子点的组分以及结构信息,综述了近年来量子点近红外调控的研究进展,并对基于结构以及组分相结合的复合调控,及其无毒近红外量子点发展进行了展望。     

Ten micrometer pixel,quantum dots color conversion layer for high resolution and full color active matrix micro‐LED display

A fine patternable quantum dots (QDs) color conversion layer (CCL) for high resolution and full color active matrix (AM) micro‐LED (μ‐LED) display is demonstrated. QDs CCL could be patterned until 10 μm using photolithography process. It is found that multicoatings with red and green QDs (R‐ and G‐QDs) CCLs on LED array can provide full color AM display.     

Amplification of fluorescence emission of CdSe/ZnS QDs entrapped in a sol-gel matrix, a new approach for detection of trace level of PAHs

In this work, CdSe/ZnS core/shell QDs with emission wavelengths of 535 nm, 545 nm, 555 nm and 575 nm were synthesized and the ligands on their surface were exchanged with mercaptopropionic acid (MPA) to make them water-soluble. Hydrophilic QDs were incorporated into a sol-gel GA matrix of 3-aminopropyl trimethoxysilane (APTMS) and 3-glycidoxypropyl trimethoxysilane (GPTMS) to fabricate QD-entrapped membranes. The fluorescence intensity of the QDs entrapped in the sol-gel membrane was increased after being activated by the energy transfer from polycyclic aromatic hydrocarbon compounds (PAHs). The signal increase of the QDs was proportional to the increase in the concentration of the PAHs. Herein, trace levels of anthracene (ANT), phenanthrene (PHE) and pyrene (PYR) were detected through the enhancement of the fluorescence intensity of the CdSe/ZnS QD-entrapped membranes. The linear detection ranges were 0.01-0.1 μM for ANT and PHE and 0.005-0.05 μM for PYR. The QD-entrapped sol-gel membranes also showed quite good stability for the detection of PAHs over a period of 2 months.     

Current transport and aging in direct-current powder electroluminescent display devices

Abstract— Direct-current powder electroluminescent (DCPEL) display devices were excited by unipolar voltage pulses, and current flow through the phosphor was recorded. Devices with different formed layer thicknesses were obtained by varying the forming voltage. For a fixed electric field in the formed layer, the phosphor current did not show a substantial increase as the thickness of the formed layer increased. A model is proposed in which tunnel injection from the p-Cu₂S/i-ZnS:Mn interface of a reverse-biased p-Cu₂S/i-ZnS:Mn/n-SnO₂ structure is thought to be the controlling current mechanism. Aging studies revealed that further forming is the dominant degradation mechanism in the early stages, while load-line degradation and softening become the dominant degradation modes as the aging process is continued. The conventional DCPEL device structure was modified by introducing a thin chromium layer just prior to the deposition of the aluminum back electrode. Incorporating chromium reduced the initial series resistance of the device. A hybrid device employing a thin film (1 μm) of ZnS:Mn, sandwiched between two thin dielectric layers (5 nm), was fabricated; ZnS:Mn,Cu powder was sprayed onto the thin-film sandwich. The hybrid structure showed good luminance without forming; however, device degradation with time was still present.