3-巯基丙酸和L-半胱氨酸修饰的ZnS掺Mn量子点对金属离子传感机理的探讨

由于量子点优异的荧光性质,基于量子点的荧光分析法的应用已经十分广泛,而量子点的磷光性质及其在分析检测中的应用得到的关注仍然较少。相对荧光分析法,室温磷光法（Room—temperature phosphorescence．RTP）具有很多的优点：磷光相对于荧光是一种更为少见的现象,     

发光纳米材料和量子点化学传感及其机理

介绍了荧光和磷光纳米材料的种类,如无机半导体量子点,金属离子掺杂的半导体量子点,金属纳米粒子或纳米簇,硅点,碳点和石墨烯点等。接着阐述了这些纳米材料的光致发光的光物理机制和猝灭或增强的一般性原理。最后简要综述了量子点或纳米材料发光的猝灭或增强现象在化学传感中的应用和具体的响应机理。     

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。     

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=0.99649).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     

多点光纤气体传感系统在煤矿中应用的可行性探讨

阐述了光纤气体传感器的结构及工作原理,介绍了多点光纤气体传感系统OptoSniff的工作原理及其采用的直接探测和TDLS技术,并进行了实验室测试。结果表明,该系统具有传输距离长、响应时间快、测量精度高、不用定期标校的优点。该系统在煤矿中应用还存在无法实现就地声光报警等问题,需进一步研究。     

伽马辐照对量子点嵌入式HEMT力敏结构的影响

辐射对空间通信系统中使用的传感器件的不利影响是需要重点考虑的问题,作为力学传感器件的核心部件,对力敏传感单元的抗辐照特性的研究就尤为重要.设计了一种InAs量子点(QD)嵌入式高电子迁移率晶体管(HEMT)力敏结构,通过60Co-γ射线对InAs QD-HEMT结构进行了不同剂量的辐照,并对辐照前后结构的电学特性、力敏...     

PVP／CdS量子点修饰电极的制备及其对肌红蛋白的直接电化学研究

该文采用溶胶-凝胶法制备了聚乙烯吡咯烷酮(PVP)表面修饰的硫化镉(CdS)半导体量子点,用透射电镜(TEM)、X射线衍射(XRD)等手段进行了表征;将其修饰在玻碳电极(GC)表面制得量子点修饰电极,并研究了肌红蛋白(Myoglobin,Mb)在该量子点修饰电极上的电化学行为.实验结果表明,PVP/CdS量子点修饰电极对肌红蛋白具有催化还原作用,且还原峰电流与被测蛋白质浓度呈良好线性关系.流动注射分析结果进一步表明该量子点修饰电极具有高的稳定性和好的重现性,检出限为2.0×10.mol/L,该电极可作为检测肌红蛋白的新型高灵敏度电化学传感器.     

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.     

2-Mercaptobenzothiazole benzoates as highly sensitive fluorescent enhancement chemosensors for transition metal ions

A new set of 2-mercaptobenzothiazole benzoates for highly sensitive fluorescent chemosensors of transition metal ions was synthesized and their fluorescence enhancement was obtained in the presence of transition metal ions such as Cd²⁺ and Hg²⁺, especially Zn²⁺, which results from the suppression of radiationless transitions from the nπ^* state in the chemosensors.     

基于功能化核酸和金属离子的荧光传感

荧光传感器能够将微观的分子识别事件转换成宏观可测的荧光信号,荧光法在灵敏度、选择性和实时原位检测等方面优势突出.该文主要介绍以功能化核酸和金属离子相互作用为基础而设计的荧光传感器的研究进展.     

Polymer-grafted QCM chemical sensor and application to heavy metal ions real time detection

A flow type quartz crystal microbalance (QCM) chemical sensor was developed for monitoring heavy metal ions in aqueous solutions (that is suitable for environmental monitoring). The sensor is based upon surface chelation of the metal ions at multifunctional polymer modified gold electrodes on 9 MHz AT-cut quartz resonators, functioning as a QCM. New processes have been developed which enable to obtain surface-modified gold electrodes with high heavy metal ions complexing ability. These polymer grafted QCM sensors can selectively adsorb heavy metal ions, such as copper, lead, chrome and cadmium, from solution over a wide range from 0.01 to 1000 ppm concentration by complexation with functional groups in the polymers. Cations typically present in natural water did not interfere with the detection of heavy metals. X-Ray Reflectivity (XRR) and Total Reflection X-ray Fluorescence (TXRF) were carried out to characterise the unmodified and modified gold surfaces as well as to verify the possibility to selectively bond and remove metal ions.     

Layer-by-layer self-assembly CdTe quantum dots and molecularly imprinted polymers modified chemiluminescence sensor for deltamethrin detection

A novel chemiluminescence sensor for determination deltamethrin was firstly reported based on CdTe quantum dots and deltamethrin imprinted polymers by layer-by-layer assembly modified on the surface of slide glass, whose shape was the same as the bottom of 96 well micro-plate. The binding characteristic of the imprinted polymers to deltamethrin was evaluated by equilibrium binding experiments and the morphology was studied by scanning electronic microscope. Scatchard analysis was carried out to estimate the binding parameters of the imprinted polymers. The water-soluble TGA-capped CdTe quantum dots were prepared. NaHTe was used as the Te precursor for CdTe quantum dots synthesis. Under the optimum conditions, the chemiluminescence intensity had a linear relationship against the concentration of deltamethrin over the range of 0.053-46.5 μg mL⁻¹ with a lower detection limit of 0.018 μg mL⁻¹. The regression equation was ΔI = 2225 + 107c (c: μg mL⁻¹) with a correlation coefficient of 0.9973. The relative standard deviation was 4.7%. The presented method was applied successfully to the determination of deltamethrin in real samples with satisfactory results.     

基于纳米金／石墨烯－壳聚糖－离子液体／L－半胱氨酸包覆CdTe量子点的双酚A传感器

在石墨烯、壳聚糖和1-乙基－3－甲基眯唑四氟硼酸盐（[BMIM]）复合材料（Graphene—Chits-[BMIM]）表面电沉积金,并自组装L－半胱氨酸包覆CdTe量子点,制备了修饰玻碳电极新型双酚A传感器。采用循环伏安法和电化学交流阻抗等方法研究了修饰电极的电化学特性。由于Graphene-Chits－[BMIM]复合材料中,石墨烯和[BMIMI都具有良好的导电性,该修饰电极对于双酚A有较好的电流响应。在最佳条件下,该传感器对双酚A的检测浓度范围：5．0×10^-8～7．05×10^-6mol／L,检测限为2．0×10^-8mol／L（3倍信噪比）,相关系数为0．999。     

Polythiophene based fluorescence sensors for acids and metal ions

Poly(thiophene-3-yl-acetic acid 8-quinolinyl ester) is a fluorescent material and it shows fluorescence at 540 nm. The fluorescence of poly (thiophene-3-yl-acetic acid 8-quinolinyl ester) has been studied in the presence of acids, metal ions, nucleotides and protein (l-proline). The fluorescence of polymer is quenched by the addition of HCl which could be recovered by the addition of equivalent amount of alkali. The Stern–Volmer quenching coefficient for HCl is calculated and found to be 141 M⁻¹. Moreover quenching depends on concentration of HCl. Similarly, the fluorescence of polymer is quenched by copper, cadmium and lead metal ions and quenching is sensitive to concentrations of metal ions. The Stern–Volmer quenching coefficient is 2.285 × 10³ M⁻¹ for Cu²⁺ ions, 2.287 × 10³ M⁻¹ for Cd²⁺ ions and 3.7 × 10⁴ M⁻¹ for Pb²⁺ ions. In Al³⁺, Zn²⁺, nucleotides and protein (l-proline), the fluorescence is exorbitantly increased.