【作者】 李太山；

【导师】 刘绍璞；

【作者基本信息】 西南大学 ， 分析化学， 2008， 博士

【摘要】 纳米材料具有体积效应、表面效应、量子尺寸效应和宏观量子隧道效应,使它们表现出独特的物理化学性质,因此在许多领域有着广阔的应用前景,成为当前一个热门的、前沿性的研究领域。近年来纳米材料在分析化学中的应用日益增多,其中利用它们的光谱特性而发展出的纳米探针和纳米光学传感器受到人们的关注,除了在紫外-可见吸光光谱,荧光光谱分析的应用外,在其他光谱分析中的应用也受到人们的重视。共振瑞利散射（RRS）光谱分析是二十世纪九十年代发展起来的一种分子光潜分析新技术,它既与分子中电子在入射光电磁场作用下发生受迫振动有关,又受电子能级跃迁的影响,因而它能够对研究分子结构和形态、电荷分布、键合性质以及反应特征等提供更丰富的信息。由于RRS分析法高灵敏度和简便快速而受到人们的关注,在纳米微粒的表征和分析应用方面也得到越来越多的研究。本文研究了硒化镉、硒化镉/硫化镉、碲化镉、碲化镉/硫化镉、硒化亚铜纳米晶及Eu₂O₃纳米棒的合成技术,优选了合成方法,制备了一系列具有优良光谱性能和反应能力的纳米晶。并以多种方法（透射电镜、高分辨透射电镜、X射线衍射、红外光谱、吸收光谱、荧光光谱等）对制备的纳米晶的粒径尺度、形貌和结构进行了表征。研究了它们的紫外可见吸收、荧光和共振瑞利光谱特性,并研究了这些纳米材料与某些金属离子、药物和生物大分子的相互作用及其对荧光和RRS光谱的影响,探索利用纳米晶做探针建立以荧光和RRS法测定某些金属离子、药物和生物大分子的可能性,从而为进一步拓展纳米晶做探针在分析化学中的应用创造了条件。一、硒化镉纳米晶的制备、表征及其与某些金属离子和药物相互作用的荧光和RRS光谱研究以柠檬酸钠、巯基乙酸钠、巯基琥珀酸等为包裹剂,硒粉为硒源,氯化镉为镉源,水或氨水为介质,KBH₄作为还原剂,水相合成了CdSe纳米晶。通过透射电镜（TEM）、高分辨透射电镜（HRTEM）、X-射线衍射（XRD）等对其结构、形貌进行了分析,通过荧光光谱、紫外可见光谱和RRS光谱对其光谱性质等进行了研究。并研究某些金属离子及抗癌药物多柔比星对CdSe纳米晶荧光和RRS的影响。结果表明,以巯基乙酸包裹效果最好。其中pH 11.2及Cd:Se:KBH₄:巯基乙酸=1.0:0.5:2.0:2.5的条件下,制备的纳米晶粒径在2-4 nm,纳米晶颗粒清晰并具有较强荧光,其最大激发和最大发射波长分别为与277 nm和556 nm处,与此同时CdSe纳米晶在320 nm和559 nm处有两个散射峰。研究了CdSe纳米晶与Na（Ⅰ）、K（Ⅰ）、Mn（Ⅱ）、Cu（Ⅱ）、Cd（Ⅱ）、Mg（Ⅱ）、Ni（Ⅱ）、Zn（Ⅱ）、Co（Ⅱ）和Cr（Ⅲ）离子在水溶液中的相互作用及其对荧光和RRS光谱的影响,结果表明:在水溶液中纳米晶与Cr（Ⅲ）的反应产物可使其荧光显著增强,Cu（Ⅱ）与纳米晶结合使其荧光猝灭,其余金属离子对纳米晶的荧光影响甚微,这为在水溶液中以CdSe纳米晶做探针荧光增强和荧光猝灭法测定Cr（Ⅲ）和Cu（Ⅱ）创造了条件。此时对Cr（Ⅲ）的检出限为17 ng/ml,但对测定Cu（Ⅱ）灵敏度不高。CdSe纳米晶在乙醇溶液中,荧光光谱发生变化,最大发射波长从556 nm移动至470 nm。当CdSe纳米晶与Zn（Ⅱ）、Ni（Ⅱ）、Cr（Ⅲ）、Cu（Ⅱ）反应时,在407 nm附近出现一个新的荧光峰,该荧光峰增强的顺序是Zn（Ⅱ）、Ni（Ⅱ）、Cr（Ⅲ）、Cu（Ⅱ）,对Zn（Ⅱ）的检出限是26μg╱ml,显然,对于金属离子的选择性不如水相反应。研究还表明,上述离子与8-羟基喹啉形成螯合物,导致407 nm附近荧光猝灭。但是,不论在水相或乙醇溶液中,CdSe纳米晶与上述金属离子的反应,对RRS的影响不显著,缺乏分析应用价值。还研究了CdSe纳米晶与抗癌药物多柔比星相互作用对荧光和RRS的影响,结果表明,纳米晶与多柔比星反应时将导致荧光显著猝灭,但对RRS的影响不大。荧光猝灭法对于多柔比星有较高灵敏度,其检出限为34 ng╱ml。这为以CdSe纳米晶做探针荧光猝灭法测定多柔比星创造了条件。二、硒化镉/硫化镉纳米晶的制备、表征及其与某些金属离子和药物相互作用的荧光和RRS光谱研究采用柠檬酸为包裹剂,硒粉为硒源,硫代乙酰胺为硫源,氯化镉为镉源,硼氢化钾为还原剂水相制备CdSe/CdS纳米晶,通过TEM、HRTEM、XRD等对其结构、形貌进行了表征,通过荧光光谱、紫外可见光谱和RRS光谱对其光谱性质进行了研究。并研究某些金属离子及氨基糖苷类药物对CdSe/CdS纳米晶荧光和RRS的影响。结果表明,Cd:Se:S:KBH₄:柠檬酸钠=3.0:1.0:1.0:2.0:4.0条件下,合成的CdSe/CdS纳米晶粒径在4.1-6.5 nm,它具有较强的荧光,其最大激发和最大发射波长分别位于232 nm和620 nm,荧光峰的半峰宽39 nm。研究了日光照射对CdSe/CdS纳米晶荧光性质的影响,结果表明随着日光照射时间的增加,荧光强度有所增强。纳米晶溶液暴露的气氛对荧光也有较大的影响,发现有氧存在下,荧光增强的速度将会加快,文中还考察了溶液pH值对荧光的影响,发现pH值对于荧光光谱特征和相对荧光强度均有较大的影响,其pH值的最佳区间是8.95-11.2之间。研究了CdSe/CdS纳米晶与Cu（Ⅱ）、Mn（Ⅱ）、Hg（Ⅱ）、Co（Ⅱ）、Cr（Ⅲ）、Fe（Ⅲ）的相互作用及其对荧光的影响。结果表明,纳米晶与这些金属离子反应时,能引起纳米晶的荧光猝灭。文中考察了上述6种离子适宜的反应条件和影响因素,确定了线性范围和相关系数,反应有较高的灵敏度,对于上述离子的检出限分别是:0.53 ng/ml（Cu（Ⅱ））、11.0 ng╱ml（Mn（Ⅱ））、3.9 ng╱ml（Hg（Ⅱ））、2.0 ng╱ml（Co（Ⅱ））、2.9 ng╱ml Cr（Ⅲ）、11.6 ng╱ml（Fe（Ⅲ））,因此,为以CdSe/CdS作探针测定上述离子创造了条件。与此同时,还研究了CdSe/CdS纳米晶与硫酸小诺霉素（MS）和硫酸阿米卡星（AS）等氨基糖苷类抗生素的结合作用对荧光的影响。结果表明,当纳米晶与上述药物结合时能促使荧光产生不同程度的增强,并且在一定范围内使荧光增强与药物的浓度成正比,对于上述药物的检出限分别为18.7 ng/ml（MS）、25.8 ng/ml（AS）,这就使得用CdSe/CdS做探针荧光的荧光法测定上述药物成为可能。文中还研究了CdSe/CdS纳米晶的共振瑞利散射光谱特性,散射峰位于555nm和298 nm处,当它与上述金属离子反应时,Mn（Ⅱ）、Hg（Ⅱ）、Co（Ⅱ）使RRS增强,而Cu（Ⅱ）使RRS下降,并且RRS强度的变化与相应离子的浓度在一定范围内呈线性关系,只是离子的检出限比荧光猝灭法低。但是CdSe/CdS纳米晶与MS和AS作用时,不能引起RRS的明显变化,故CdSe/CdS纳米晶不能用于上述药物的RRS法测定。三、碲化镉纳米晶的制备、表征及其与药物相互作用的荧光和RRS光谱研究以氯化镉、碲氢化钾为原料,巯基乙酸钠为包裹剂水相合成了碲化镉纳米晶,通过透射电镜、高分辨透射电镜、能量色散谱、荧光光谱、紫外可见光谱、X射线衍射对碲化镉纳米晶进行了表征,所合成的纳米晶直径为5 nm左右,属立方结构。碲化镉纳米晶溶液在制备后放置19 d其荧光量子产率从初始的37%达到97%,而最大荧光发射波长（λem）从543 nm移至510 nm,蓝移33 nm,而且在冰箱4℃可稳定至少10个月。同时碲化镉纳米晶溶液也具有一定的共振瑞利散射（RRS）,其最大散射峰位于554 nm附近。研究了碲化镉纳米晶与硫酸阿米卡星和硫酸小诺霉素的相互作用对荧光和RRS的影响。结果表明:当两者反应形成结合产物时,将使纳米晶溶液荧光显著猝灭并使RRS明显增强,并且荧光猝灭作用和RRS增强在一定的范围内与药物的浓度成正比,对于硫酸阿米卡星和硫酸小诺霉素的检出限分别为3.4 ng/ml和2.6 ng/ml（荧光猝灭法）及15.2 ng/ml和14.0ng╱ml（RRS法）,方法具有高灵敏度。因此为用碲化镉纳米晶作荧光探针荧光猝灭法和RRS法测定氨基糖苷类药物创造了条件。四、碲化镉/硫化镉纳米晶的制备、表征与金属离子作用及用于生物分子标记的研究以氯化镉、碲粉、硼氢化钾为原料,巯基乙酸为包裹剂,水相合成碲化镉/硫化镉纳米晶。通过TEM、HRTEM、XRD等对其结构、形貌进行了表征,通过荧光光谱、紫外可见光谱和RRS光谱对其光谱性质进行了研究。研究某些金属离子对CdTe/CdS纳米晶荧光和RRS的影响,并将CdTe/CdS纳米晶用于生物材料的特异性标记。研究结果表明,在Cd:Te:巯基乙酸钠=2:1:4.8条件下,合成的CdTe/CdS纳米晶粒径约6 nm,它具有强的荧光,荧光量子产率可达到98%。其最大激发和最大发射波长分别位于253 nm和511 nm。pH对纳米晶荧光影响较大,酸性介质中荧光猝灭,在pH 7.0-11.2之间荧光强而稳定。研究了此种纳米晶与金属离子反应时对于荧光和RRS的影响,结果表明Cu（Ⅱ）、Co（Ⅱ）、Ni（Ⅱ）和Cr（Ⅲ）均可使荧光发生不同程度的猝灭作用,其中以Cu（Ⅱ）的猝灭作用最强,其次是Co（Ⅱ）、Ni（Ⅱ）和Cr（Ⅲ）,在一定范围内荧光猝灭值与金属离子的浓度成正比,对于上述金属的检出限分别是1.0 ng╱ml（Cu（Ⅱ））、1.8 ng/ml（Co（Ⅱ））、3.5 ng╱ml（Ni（Ⅱ））、3.4 ng╱ml（Cr（Ⅲ））。并以Cu（Ⅱ）为例,研究了适宜的反应条件和共存物质的影响,表明方法有一定的选择性,从而为用CdTe/CdS纳米晶做探针荧光猝灭法测定上述离子,特别是Cu（Ⅱ）离子奠定了基础。纳米晶与Cu（Ⅱ）、Co（Ⅱ）和Ni（Ⅱ）反应时,导致纳米晶溶液RRS降低,在一定范围内RRS降低值与金属离子的浓度成正比,但是与荧光法相比,RRS法灵敏度较低,线性关系稍差。将CdTe/CdS纳米晶用于生物分子标记,结果发现,牛血清白蛋白（BSA）、兔抗羊IgG抗体和羊抗鼠IgG三种蛋白质均能与纳米晶结合,使蛋白质带有绿色荧光。CdTe/CdS纳米晶和羊抗鼠IgG结合之后,保持了二抗的活性,能与鼠抗人IgG抗原作用实现特异性识别。与羊抗鼠IgG结合的CdTe/CdS纳米晶,再用BSA封闭纳米晶表面剩余位点,CdTe/CdS-羊抗鼠IgG能与已结合于细胞表面CK19鼠抗人IgG结合,使细胞被荧光标记。五、硒化亚铜和氧化铕纳米材料的制备、表征及其荧光光谱研究建立了一种室温水相合成Cu₂Se纳米晶的新方法,以硝酸铜、硒粉和巯基乙酸钠为原料在氨水介质中室温合成了Cu₂Se纳米晶。通过透射电镜、高分辨透射电镜、X射线衍射、荧光光谱和紫外可见光谱等手段分析、表征了合成的纳米晶。Cu₂Se呈硒铜矿结构,尺寸为长20-40nm,宽10-20nm。Cu₂Se纳米晶具有较强的荧光其最大激发和发射波长分别位于253 nm和585 nm。建立了合成一维Eu₂O₃纳米材料的简易方法,在表面活性剂（SDS）作用下,以丁醇水溶液作溶剂,六次甲基四胺做碱源合成了Eu₂O（CO₃）2·H₂O和Eu₂O₃纳米棒。通过透射电镜、高分辨透射电镜、扫描电镜、X射线衍射等手段分析、表征了合成的一维产品。Eu₂O₃纳米棒直径为80-300纳米,长为1-5微米。同时讨论了纳米棒的形成机理。Eu₂O₃纳米棒最大吸收波长位于317nm,发生蓝移47nm,呈现出明显的量子限域效应。Eu₂O₃纳米棒在329nm和617nm呈现出荧光峰。上述两种纳米材料均有较好的荧光特性。但是因其水溶性较差而影响了它们与金属离子、药物和生物大分子的反应能力。今后将从合成方法及表面改性等方面改善其水溶性,使之能在分析化学中得到更好的应用。更多还原

【Abstract】 Due to volume effect,surface effect,quantum size effect and macroscopic quantum tunneling effect,nanomaterials exhibit unique physical and chemical properties.Therefore,with broad prospects for application in many fields,they have become a hot and advanced research realm.Recently,more nanomaterials have been applied to analytical chemistry,in which nanoprobes and nano optical sensors developed by using their spectral characteristics have attracted much attention.Besides the application in ultraviolet-visible absorption spectra and fluorescence spectra analysis,other spectroscopic applications have also drawn considerable notice.Resonance Rayleigh Scattering（RRS） is a new analytical technique developed in 1990s.RRS is related to both the compelled vibration of the electrons in molecule and the electronic energy level transitions under the effect of the incident light electromagnetic field.Therefore it can offer more information about molecular structure and conformation,charge distribution,linkage nature as well as the reaction characteristics and so on.More attention has been paid to RRS method,since it is very sensitive and simple in monitoring some ions,some drugs and biomolecules.It has been also applied in the characterization and analysis of nanoparticles.In this thesis,the synthetic methods of cadmium selenide,cadmium selenide/ cadmium sulfide,cadmium telluride,cadmium telluride/ cadmium sulfide,cuprous selenide nanocrystals（NCs） and europium oxide nanorods were researched,and some nanocrystals with fine optical properties and reactivities were obtained by optimized synthetic methods.The size,structure and conformation of the nanocrystals prepared were characterized by various methods（transmission electron microscopy（TEM）, high-resolution transmission electron microscopy（HRTEM）,X-ray diffraction（XRD）, infrared absorption spectrum（IR））.The properties of ultraviolet-visible absorption spectra,fluorescence spectra and RRS spectra of the NCs were investigated.The interactions of the NCs with some metal ions,drugs and biomolecules and the effect of the interactions on fluorescence and RRS spectra were examined.The possibility of the determination of metal ions,drugs and biomolecules by exploiting nanocrystals as fluorescence and RRS probes was explored.Therefore,it provides better conditions for further application of NCs probes in analytical chemistry.1.Study on syntheses,characterizations of cadmium selenide NCs and effects of their interactions with some metal ions and drugs on fluorescence and RRS spectraCadmium selenide NCs were obtained by the reaction of Cd（Ⅱ） with Se（Ⅱ）,with aqueous or aqueous ammonia solution as solvent,KBH₄ as reducer,selenium powder as selenium source,cadmium chloride as cadmium source and sodium mercaptoacetate （SMA）,sodium mercaptosuccinate（SMS） and sodium citrate（SC） as wrapper.The structure and conformation of the NCs were characterized by TEM,HRTEM and XRD. The properties of ultraviolet-visible absorption spectra,fluorescence spectra and RRS spectra of the NCs were investigated.The effects of some metal ions and anticarcinogen doxorubicin hydrochloride（DH） on fluorescence and RRS of CdSe NCs were also studied.Among the wrappers,sodium mercaptoacetate（SMA） showed the best capping effect.CdSe NCs prepared under the conditions of Cd:Se:KBH₄:SMA=1:0.5:2.0:2.5 and pH11.2 showed higher intensity of fluorescence and the clear edge of the NCs.The average diameter of the CdSe NCs was 2-4 nm.The maximum excitation and emission wavelengths were about 277 nm and 556 nm.The RRS peaks of CdSe NCs were located at about 320 nm and 559 nm.The interactions of CdSe NCs with certain metal ions in aqueous solution,such as Na（Ⅰ）,K（Ⅰ）,Mn（Ⅱ）,Cu（Ⅱ）,Cd（Ⅱ）,Mg（Ⅱ）,Ni（Ⅱ）,Zn（Ⅱ）,Co（Ⅱ）,Cr（Ⅲ）,and the effects of their interactions on fluorescence spectra and RRS spectra were investigated. The results indicate that Cr（Ⅲ）can enhance the fluorescence greatly,while Cu（Ⅱ） can result in the quenching of fluorescence of the NCs.The other ions have little influence on the fluorescence.This offers the possibility of determinations of Cr（Ⅲ） and Cu（Ⅱ） using CdSe NCs as fluorescence probe.The detection limit for Cr（Ⅲ） was 17 ng/ml, however the determination sensitivity of Cu（Ⅱ） was relatively lower.In alcohol solution,fluorescence peak of CdSe NCs shifted from 556 nm to 470nm.While the NCs reacted with Zn（Ⅱ）,Ni（Ⅱ）,Cr（Ⅲ）,Cu（Ⅱ）,and a new peak appeared at 407nm.The order of the fluorescence intensity was CdSe-Zn＞CdSe-Ni＞CdSe-Cr＞CdSe-Cu.The detection limit for Zn（Ⅱ） was 26μg/ml.Obviously, selectivities of interactions of metal ions with CdSe NCs in alcohol were poorer than those in aqueous solution.It was also found that the interactions of above ions with 8-Hydroxyquinoline（HQ） could cause fluorescence quenching at 407 nm.However,whether in aqueous or alcohol solution,the effects of metal ions on the RRS of CdSe NCs were unobvious.Therefore,the RRS methods mentioned above can not be applied in analysis.The effect of the interactions of doxorubicin hydrochloride（DH） with CdSe NCs on fluorescence and RRS was also studied.The results indicated that DH could result in the fluorescence quenching of the NCs,on the other hand,DH has little influence on the RRS spectra.That fluorescence quenching method exhibited high sensitivity and the detection limit for DH was 34 ng/ml.This provides a feasibility for utilizing CdSe NC as fluorescence probe to determine DH.2.Study on syntheses,characterizations of cadmium selenide/cadmium sulfide nanocrystals and effects of their interactions with some metal ions and drugs on fluorescence and RRS spectraCadmium selenide/cadmium sulfide NCs were prepared by the reaction of Cd（Ⅱ） with Se（Ⅱ） and S（Ⅱ）,with water as solvent,KBH₄ as reducer,selenium powder as selenium source,cadmium chloride as cadmium source,thioacetamide as sulphur source and sodium citrate（SC） as wrapper.The structure and conformation of the NCs were characterized by TEM,HRTEM and XRD.The properties of ultraviolet-visible absorption spectra,fluorescence spectra and RRS spectra of the NCs were investigated. The effects of some metal ions and aminoglycoside antibiotics on fluorescence and RRS of CdSe/CdS NCs were also studied. As the results indicated,CdSe/CdS NCs prepared under the conditions of Cd:Se: S:KBH₄:SC=3.0:1.0:1.0:2.0:4.0 showed higher intensity of fluorescence and the average diameter of the NCs was 4.1-6.5 nm.The maximum excitation and emission wavelengths were about 232 nm and 620 nm.The fluorescence peak width at half height was only 39 nm.The effects of normal room light on the fluorescence characteristics of the CdSe /CdS NCs were investigated.It was found that the intensity of fluorescence of the NCs increased with the time extension.The exposed atmosphere of the NCs solution had great influence on fluorescence.The fluorescence was more enhanced under air than that under nitrogen.The effects of pH on the intensity of the fluorescence were also investigated.It was found that pH value had an obvious influence on the characteristics and intensity of the fluorescence.In pH 8.95-11.2,the fluorescence intensity was high and stable.The influences of the interactions of CdSe /CdS NCs with Cu（Ⅱ）,Mn（Ⅱ）, Hg（Ⅱ）,Co（Ⅱ）,Cr（Ⅲ） and Fe（Ⅲ） ions on fluorescence and RRS were investigated.It was found that the above six kinds of ions caused the fluorescence quenching.The conditions of interactions of the NCs with the ions were optimized.The correlation coefficients and linear ranges were obtained.The interactions had high sensitivities and the detection limits were 0.53 ng/ml（Cu（Ⅱ））,11.0 ng/ml（Mn（Ⅱ））,3.9 ng/ml （Hg（Ⅱ））,2.0 ng/ml（Co（Ⅱ））,2.9 ng/ml Cr（Ⅲ） and 11.6 ng/ml（Fe（Ⅲ））.This offers opportunities to determine above ions using CdSe/CdS NCs as fluorescence probe.The interactions of CdSe/CdS NCs with micronomicin sulfate（MS） and amikacin sulfate（AS） and its influence on fluorescence were investigated respectively.It was found that MS and AS could enhance the fluorescence of CdSe/CdS NCs in varying degrees.Under optimum conditions,the increased intensities had linear relationship with the concentrations of MS and AS.The detection limits for MS and AS were 18.7 ng mL^-1 and 25.8 ng mL^-1.This provides opportunities to determine aminoglycoside antibiotics using CdSe/CdS NCs as fluorescence probe.The resonance Rayleigh scattering（RRS） of CdSe/CdS NCs in aqueous solution was investigated.The scattering peaks were located at about 555 nm and 298 nm.It was found that Mn（Ⅱ）,Hg（Ⅱ） and Co（Ⅱ） ions increased the intensity of RRS of the NCs and Cu（Ⅱ） ions decreased the intensity of RRS.There were linear relationships between the intensity of RRS and the concentration of the ions.But the detection limits for the ions of RRS method were lower than those of fluorescence quenching method. AS and MS did not cause the obvious change of RRS of CdSe/CdS NCs,so that the NCs could not be used to determine MS and AS by the RRS method.3.Study on syntheses,characterizations of cadmium telluride nanocrytals and effects of their interactions with some drugs on fluorescence and RRS spectraCadmium telluride nanocrystals（NCs） were achieved by reaction of CdCl₂ with KHTe solution and were capped with sodium mercaptoacetate.The products were characterized by TEM,HRTEM,energy dispersive spectroscopy（EDS）,XRD, fluorescence spectra and ultraviolet-visible spectra.The CdTe NCs were of cubic structure and the average size was about 5 nm.The fluorescence quantum yield of CdTe NCs aqueous solution increased from 37%to 97%after 20 days under room light.The maximum of fluorescence(λ_em) changed from 543 nm to 510 nm and the blue shift was 33 nm.The CdTe NCs aqueous solution can be kept stable for at least 10 months under 4℃in refrigerator.The resonance Rayleigh scattering（RRS） of CdTe NCs in aqueous solution was investigated.The maximum scattering peak is located at about 554 nm. The interactions of CdTe NCs with amikacin sulfate（AS） and micronomicin sulfate （MS） were investigated respectively.The effects of AS and MS on fluorescence and RRS of CdTe NCs were analysized.It was found that AS and MS could result in the fluorescence quenching of CdTe NCs and RRS enhancement of CdTe NCs.Under optimum conditions,the fluorescence quenching intensity and the enhanced RRS intensty had linear relationship with the concentration of AS and MS,respectively.The detection limits for AS and MS were 3.4 ng mL^-1,2.6 ng mL^-1 for fluorescence quenching method,15.2 ng mL^-1,14.0 ng mL^-1 for RRS method,respectively.The methods have high sensitivities so that CdTe NCs can be used as fluorescence probes and RRS probes for the determination of aminoglycoside antibiotics.4.Study on syntheses,characterizations of cadmium telluride/cadmium sulfide nanocrytals and their interactions with some ions and labeling of biomoleculesCadmium telluride/cadmium sulfide NCs were prepared by the reaction of Cd（Ⅱ） with Te（Ⅱ）,with water as the solvent,KBH₄ as reducer,tellurium powder as tellurium source,sodium mercaptoacetate as sulphur source and wrapper.The structure and conformation of the NCs were characterized by TEM,HRTEM and XRD.The properties of ultraviolet-visible absorption spectra,fluorescence spectra and RRS spectra of the NCs were investigated.The influences of the interactions of CdTe/CdS NCs with some ions on fluorescence and RRS were examined.CdTe/CdS NCs were used for specific labeling of bio-material.The CdTe/CdS NCs prepared under the conditions of Cd:Te:SMA=2:1:4.8 showed higher intensity of fluorescence.The average diameter of the NCs was about 6 nm.The fluorescence quantum yield was 98%.The maximum excitation and emission wavelengths were about 253 nm and 511 nm,respectively.The effect of pH value on fluorescence of the NCs was examined.It was found that in acidic medium,the fluorescence of the NCs was quenched and in pH 7.0-11.2,the fluorescence was the highest and stable.The influences of the interaction of CdTe /CdS NCs with some ions on fluorescence and RRS were investigated.It could be seen from the experiments that Cu（Ⅱ）,Co（Ⅱ）,Ni（Ⅱ） and Cr（Ⅲ） ions resulted in fluorescence quenching in varying degrees,among them,Cu（Ⅱ） exhibited the greatest quenching effect and the others were in the order of Co（Ⅱ）＞Ni（Ⅱ）＞Cr（Ⅲ）.There were linear relationships between intensity of fluorescence and the concentration of the ions.The detection limits for the ions were 1.0 ng/ml（Cu（Ⅱ））,1.8 ng/ml（Co（Ⅱ））,3.5 ng/ml（Ni（Ⅱ）） and 3.4 ng/ml（Cr（Ⅲ））.Taken Cu（Ⅱ） as an example,the optimum reaction conditions and the influences of the coexisting substances were investigated.It was found that the fluorescence quenching method had certain selectivity,which offered a sound basis for the determination of the above ions,esp.Cu（Ⅱ） by utilizing fluorescence quenching method using CdTe/CdS NCs as fluorescence probe.When CdTe/CdS NCs reacted with Cu（Ⅱ）,Co（Ⅱ） and Ni（Ⅱ）,the intensity of RRS decreased.It was found that there are linear relationships between the intensity changes of RRS and the concentrations of ions in certain ranges.Compared with fluorescence methods,the sensitivities and the correlation coefficients of the RRS methods were lower.The CdTe/CdS NCs were used to label biomolecules.It was found that the CdTe/CdS NCs could combine with BSA,rabbit anti-goat IgG and goat anti-mouse IgG and made the proteins showed green fluorescence.The combination of CdTe/CdS NCs with goat anti-mouse IgG could keep the second antibody activity and their binding with mouse anti-human IgG could attain specific recognition.Using BSA to enclose the active points on the surface of the CdTe/CdS NCs binded by goat anti-mouse IgG,it could combine with CK19 mouse anti-human IgG on the surface of cells to realize the fluorescence labeling of the cells.5.Study on syntheses,characterizations and fluorescence spectra of Cu₂Se nanocrystals and Eu₂O₃ nanorodsA simple new method under normal room temperature has been developed to prepare cuprous selenide NCs by the reaction of copper nitrate trihydrate with selenium and sodium mercaptoacetate in aqueous ammonia system.Cu₂Se NCs were characterized by TEM,HRTEM,XRD,electron diffraction（ED）,fluorescence spectrum and ultraviolet-visible absorption spectrum.Cu₂Se NCs showed berzelianite structure with 20-40 nm in length and 10-20 nm in width.The fluorescence excitation and emission peaks were located at 253 nm and 585 nm,respectively.A simple process was proposed for synthesis of Eu₂O₃ nanorods.Eu₂O（CO₃）₂·H₂O nanorod monocrystalline and Eu₂O₃ nanorods were obtained by means of surfactant assistance,with aqueous butanol solution as the solvent and hexamethylene tetramine as the base.The samples obtained were analyzed and characterized by TEM,HRTEM, SEM and XRD.The Eu₂O₃ nanorod was about 80-300 nm in diameter and 1-5μm in length.The formation mechanism of 1D product was also discussed.The maximum absorption peak of the Eu₂O₃ nanorods was located at 317nm.A blue-shift of the peak was 47nm,which showed the obvious quantum-confinement effect.The peaks of fluorescence emission can be seen clearly at 329 nm and 617 nm.Cu₂Se NCs and Eu₂O₃ nanorods mentioned above showed some fluorescence characteristics. However,they could not react with metal ions,medicines and biomolecules effectively because of their poor water-solubility.This should be improved by adopting new synthesis methods and surface modification in order to apply the NCs in analytical chemistry in the future effectively.更多还原