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1.
合成了巯基乙酸(TGA)修饰的壳核型CdTe/CdS量子点(TGA-CdTe/CdSQDs).利用紫外-可见光谱吸收、荧光光谱研究TGA-CdTe/CdS QDs与盐酸药根碱(JH)的相互作用机理.在pH值为7.4的tris-HCl缓冲溶液介质中,QDs与JH相互作用后使QDs的荧光呈线性猝灭,并有良好的线性关系(r=0.999 1),线性范围0.011 ~ 10 mg/L,检出限(3σ为3.3×10-3 mg/L,因此可以作为一种快速、简便、定量测定盐酸药根碱的新方法.  相似文献   

2.
在水相中合成了硫普罗宁(Tiopronin,TP)修饰的CdTe/CdS量子点(TP-CdTe/CdS QDs).利用紫外-可见吸收光谱、荧光光谱研究了TP-CdTe/CdS QDs与丝裂霉素(mitomycin C,MMC)的相互作用机理.在pH=7.6的tris-HCl缓冲溶液介质中,TP-CdTe/CdS QDs与MMC相互作用,使TP-CdTe/CdS QDs的荧光发生猝灭,并且QDs的荧光强度与MMC的浓度有良好的线性关系(r=0.9991),线性范围4.7×10-9~1.2×10-8g/mL,检出限(3σ)为1.4×10-g/mL.此方法快速简便,用于尿样中丝裂霉素的测定,实验结果令人满意.  相似文献   

3.
采用水相法合成了谷胱甘肽(GSH)修饰的CdTe/CdS量子点(GSH-CdTe/CdS QDs).透射电子显微镜表征结果表明,GSH-CdTe/CdS QDs的粒径分布均匀,分散性好.在Tris-HCl(pH=7.6)缓冲液中,由于静电引力作用,带正电的盐酸洛美沙星(LMFH)-Cu(Ⅱ)配合物[LMFH-Cu(Ⅱ)]吸附到带负电的GSH-CdTe/CdSQDs表面形成基态复合物,导致GSH-CdTe/CdS QDs的荧光猝灭.随后,向GSH-CdTe/CdS QDs-LMFH-Cu(Ⅱ)配合物体系中加入鲱鱼精DNA(hsDNA),hsDNA可诱导LMFH-Cu(Ⅱ)配合物从GSH-CdTe/CdS QDs表面脱落而嵌入到hsDNA的双螺旋结构中,使GSH-CdTe/CdS QDs的荧光恢复.通过对GSH-CdTe/CdS QDs荧光的可逆调控,利用荧光光谱、紫外-可见吸收光谱和共振瑞利散射光谱研究了hsDNA与LMFH-Cu(Ⅱ)配合物的相互作用.通过对比GSH-CdTe/CdS QDs与LMFH相互作用的光谱性质,讨论了GSH-CdTe/CdSQDs-LMFH-Cu(Ⅱ)-hsDNA的相互作用机理,模拟了作用过程,从而建立了一种研究氟诺喹酮类药物的金属配合物与核酸相互作用机制的光谱方法.  相似文献   

4.
CdTe/CdS量子点荧光探针测定司帕沙星含量   总被引:2,自引:1,他引:1  
在水溶液中合成了巯基乙酸修饰的CdTe/CdS量子点(QDs),基于喹诺酮类抗生素司帕沙星与CdTe/CdS量子点的荧光猝灭作用,建立了用CdTe/CdS量子点作为荧光探针检测微量司帕沙星的新方法.用荧光光谱、紫外光谱研究了CdTe/CdSQDs与司帕沙星的相互作用.研究表明:该荧光猝灭的机理属于静态猝灭,反应的作用机理可能是司帕沙星促使QDs表面键合的有机分子发生变化,在Cd的电子空穴上形成了碲氧复合物,致使荧光猝灭.实验发现,pH为6.50的磷酸缓冲溶液中,量子点的浓度为3.75×10-4mol/L时,司帕沙星的浓度在0.1~50μg/mL范围与CdTe/CdS量子点荧光猝灭强度呈良好的线性关系,相关系数0.9992,检出限0.01399μg/mL.该方法简便、快捷、灵敏、线性范围宽,应用于司帕沙星片剂司帕沙星含量的测定,分析结果与标示量一致;用于牛奶中司帕沙星残留量的检测,回收率在93.1%~102.4%,结果满意.  相似文献   

5.
以巯基乙酸为稳定剂,在水溶液中合成了CdTe/CdS量子点(QDs),并基于QDs与锑混合后发生荧光猝灭作用,建立了以CdTe/CdS QDs作为荧光探针检测微量锑的新方法。研究表明,在pH值为4.80的柠檬酸-柠檬酸钠中,反应时间为10min时,锑浓度在0.03~2.50μg/mL范围与CdTe/CdS QDs的荧光猝灭程度呈良好的线性关系,相关系数为0.9969,检出限为2.60×10-3μg/mL。  相似文献   

6.
制备了巯基乙酸(TGA)修饰的CdTe/CdS量子点(QDs),并基于pH值为5.80的柠檬酸-柠檬酸钠缓冲溶液和十二烷基苯磺酸钠(SDBS)存在下,Ag(Ⅰ)与CdTe/CdS QDs的荧光猝灭作用,建立了以CdTe/CdS QDs为荧光探针测定样品中痕量Ag(Ⅰ)含量的新方法。室温下,Ag(Ⅰ)的质量浓度在3.0~700μg/L范围内与CdTe/CdS QDs荧光猝灭强度呈线性关系,相关系数为0.9988,方法的检出限为1.0μg/L。方法应用于环境废水中痕量Ag(Ⅰ)含量检测,并做回收试验,测得回收率为95.2%~103.0%。  相似文献   

7.
以巯基乙酸(TGA)为稳定剂制备CdSe/CdS量子点(CdSe/CdS QDs)。在弱酸性条件下,灭蝇胺(Cyr)可使CdSe/CdS QDs的荧光增强,据此建立了以CdSe/CdS QDs为荧光探针快速检测辣椒、豇豆、苦瓜、黄瓜和圣女果中Cyr残留的新方法,并优化了Cyr的测定条件。结果表明,当激发波长(λ_(ex))为481 nm时,CdSe/CdS QDs的最大发射波长(λ_(em))为580 nm,且不受基质背景荧光干扰。在最优条件下,Cyr在5.0~120 nmol/L范围内与CdSe/CdS QDs的荧光强度增强呈线性关系,相关系数(r)均不低于0.999 1,检出限(LOD,S/N=3)为0.8~1.4 nmol/L,定量下限(LOQ,S/N=10)为2.4~4.6 nmol/L;在4、40、100μg/kg加标水平下的回收率为82.5%~108%,相对标准偏差(RSD,n=3)不大于6.9%。该方法选择性好、灵敏度高、操作简便,应用于实际蔬菜中Cyr的测定,结果满意。  相似文献   

8.
采用胶体化学法制备了四种表面修饰有不同有机功能团的CdS量子点(QDs),利用透射电子显微镜(TEM)、紫外-可见(UV-Vis)吸收光谱、光致发光(PL)光谱、开孔Z扫描技术分别研究了四种CdS样品的线性光学和非线性光学性能.结果表明:颗粒大小、表面形貌和缺陷浓度是影响CdS QDs非线性光学性能的主要因素.  相似文献   

9.
在水相中合成了巯基丙酸( MPA)包覆的CdTe量子点(QDs),采用透射电子显微镜和原子力显微镜对其进行表征.利用荧光光谱、紫外-可见吸收光谱和红外光谱研究了CdTe QDs与绿原酸(CHA)的相互作用.结果表明,CHA可显著猝灭CdTe QDs的荧光,在一定的浓度范围内,荧光猝灭值与CHA的浓度呈现一定的线性关系.推断其主要猝灭机理为动态猝灭,并实现了荧光光谱法测定CHA.向CdTe QDs-CHA体系中加入血管紧张素Ⅰ (Ang Ⅰ)后,CdTe QDs荧光在一定浓度范围内逐渐恢复,从而实现了CdTe QDs的荧光可逆调控.CdTe QDs荧光的猝灭与恢复过程对于荧光传感的设计以及荧光可逆调控机理的研究具有指导意义.  相似文献   

10.
在水相中合成了巯基丙酸(MPA)包覆的CdTe量子点(QDs), 采用透射电子显微镜和原子力显微镜对其进行表征. 利用荧光光谱、紫外-可见吸收光谱和红外光谱研究了CdTe QDs与绿原酸(CHA)的相互作用. 结果表明, CHA可显著猝灭CdTe QDs的荧光, 在一定的浓度范围内, 荧光猝灭值与CHA的浓度呈现一定的线性关系. 推断其主要猝灭机理为动态猝灭, 并实现了荧光光谱法测定CHA. 向CdTe QDs-CHA体系中加入血管紧张素Ⅰ(AngⅠ)后, CdTe QDs荧光在一定浓度范围内逐渐恢复, 从而实现了CdTe QDs的荧光可逆调控. CdTe QDs荧光的猝灭与恢复过程对于荧光传感的设计以及荧光可逆调控机理的研究具有指导意义.  相似文献   

11.
以巯基乙酸为稳定剂,在水溶液中合成CdTe/CdS量子点,基于量子点与Cu2+混合后发生荧光猝灭作用,建立CdTe/CdS量子点作为荧光探针检测微量铜的新方法。在pH 4.60的HAc-NaAc缓冲溶液中,反应时间为10 min时,Cu2+质量浓度在0.01~1.00μg/mL范围与CdTe/CdS量子点的荧光猝灭程度呈良好的线性关系,相关系数为0.9978,检出限为9.90×10-3μg/mL。方法可以用于雨水、自来水和延河水中Cu2+的分析。  相似文献   

12.
CdTe/CdS半导体量子点作为农药百草枯的高灵敏传感器   总被引:3,自引:1,他引:2  
用硫普罗宁(Tiopronin,TP)作为稳定剂合成了水溶性的高荧光CdTe/CdS量子点.研究了该量子点与10种农药的相互作用.实验发现,当农药浓度为4.76×10-6mol/L时,农药百草枯(Paraquat)能显著猝灭CdTe/CdS量子点的荧光,使其荧光强度下降87.3%,而分别加入乙酰甲胺磷及辛硫磷等其它9种农药,仅能使CdTe/CdS量子点的荧光强度下降0.1%~5.1%,显示了该CdTe/CdS量子点对百草枯的特异性传感作用.采用吸收光谱和时间分辨荧光动力学研究了百草枯对CdTe/CdS量子点的荧光猝灭机理.计算得出荧光强度猝灭的Stern-Volmer常数K为2.03×106,而寿命猝灭的Stern-Volmer常数K为4.25×105.结果表明,百草枯对CdTe/CdS量子点的荧光猝灭主要为静态过程,而动态过程的贡献较小.利用二者的猝灭作用建立了对农药百草枯的高灵敏检测新方法,校正曲线的线性范围为9.90×10-9~1.50×10-6mol/L,检出限为6.35×10-9mol/L,R=0.999.用该方法对3种食品和3种水样中残留农药进行了检测,加标回收率均在82.2%~98.5%之间,其相对标准偏差为2.62%~8.35%.  相似文献   

13.
A novel method has been developed for uric acid analysis based on the quenching of fluorescence emission from CdS quantum dots by uric acid. Also, the effect of the presence of different surfactant agents, in order to improve the fluorescent signals of the CdS QDs, has been investigated, and the cetyltrimethyl ammonium bromide (CTAB) was selected. Under optimum conditions, the calibration graph was linear over the range of 0.1 ng/mL to 12.0 ng/mL (r = 0.9950). The limit of detection (S/N = 3) was 0.1 ng/mL. The RSD for ten determinations of 5.0 ng/mL uric acid was 3.5%. The method was applied to determine uric acid in human serum and urine sample with satisfactory results.  相似文献   

14.
Based on CdTe/CdS quantum dots (CdTe/CdS QDs) fluorescence (FL) reversible control, a new and sensitive FL sensor for determination of anthraquinone (AQ) anticancer drugs (adriamycin and daunorubicin) and herring sperm DNA (hsDNA) was developed. Under the experimental conditions, FL of CdTe/CdS QDs can be effectively quenched by AQ anticancer drugs due to the binding of AQ anticancer drugs on the surface of CdTe/CdS QDs and photoinduced electron transfer (PET) process from CdTe/CdS QDs to AQ anticancer drugs. Addition of hsDNA afterwards brought the restoration of CdTe/CdS QDs FL intensity, as AQ anticancer drugs peeled off from the surface of CdTe/CdS QDs and embedded into hsDNA double helix structure. The liner ranges and the detection limits of FL quenching methods for two AQ anticancer drugs were 0.33-9 μg mL−1 and 0.09 μg mL−1 for ADM and 0.15-9 μg mL−1 and 0.04 μg mL−1 for DNR, respectively. The restored FL intensity was proportional to concentration of hsDNA in the range of 1.38-28 μg mL−1and the detection limit for hsDNA was 0.41 μg mL−1. It was applied to the determination of AQ anticancer drugs in human serum and urine samples with satisfactory results. The reaction mechanism of CdTe/CdS QDs FL reversible control was studied.  相似文献   

15.
Luminescent quantum dots (QDs)-semiconductor nanocrystals are a promising alternative to organic dyes for fluorescence-based applications. We have developed procedures to use CdS to encapsulate CdTe and synthesize a new kind of functionalized CdTe/CdS QDs for the quantitative and selective determination of bovine serum albumin (BSA). Maximum fluorescence intensity was produced at pH 6.83, with excitation and emission wavelengths at 336 and 524 nm, respectively. Under optimal conditions, the straight line equation: DeltaF=6.84+62.29C (10(-6) mol dm(-3)) was found between the relative fluorescence intensity and the concentration of BSA in the range of 0-1.2 x 10(-6) mol dm(-3), and the limit of detection was 5.4 x 10(-8) mol dm(-3). Based on this approach, a novel quantitative method for the determination of BSA is presented in this paper.  相似文献   

16.
The traditional aqueous route to synthesis CdTe/CdS Core/shell (c/s) quantum dots (QDs) via decomposition of Cd-thiol complexes is usually time consuming. Herein, an ultrafast and facile aqueous synthetic approach under atmospheric pressure for CdTe/CdS c/s QDs with emission from the green to the near-infrared window (535–820 nm) is reported. With purified CdTe core QDs diluted in solution of Cd-3-mercaptopropionic acid (MPA) complexes, CdTe/CdS c/s QDs with emission wavelengths at 700 and 800 nm can be obtained within 20- and 45-min refluxing under the optimized experimental conditions, respectively. This is the most rapid way to prepare CdTe/CdS c/s QDs in aqueous phase, and the obtained QDs were highly luminescent without postsynthesis treatment. The influences of various experimental factors, including Cd2+ concentration, MPA-to-Cd ratio, pH value, and dilution ratio on the growth rate and luminescent properties of the obtained CdTe/CdS c/s QDs, have been taken into consideration. The three processes “purification-dilution-addition” ensure the synthesis environment with high pH value and low core concentration and have a marked impact on the rapid synthesis rate and the resulting high fluorescence of CdTe/CdS c/s QDs.  相似文献   

17.
In this paper, we report a simple, selective, sensitive and low-cost turn-on photoluminescent sensor for cysteine and homocysteine based on the fluorescence recovery of the CdTe/CdS quantum dots (QDs)–phenanthroline (Phen) system. In the presence of Phen, the fluorescence of QDs could be quenched effectively due to the formation of the non-fluorescent complexes between water-soluble thioglycolic acid (TGA)-capped QDs and Phen. Subsequently, upon addition of cysteine and homocysteine, the strong affinity of cysteine and homocysteine to QDs enables Phen to be dissociated from the surface of QDs and to form stable and luminescent complexes with cysteine and homocysteine in solution. Thus, the fluorescence of CdTe/CdS QDs was recovered gradually. A good linear relationship was obtained from 1.0 to 70.0 μM for cysteine and from 1.0 to 90.0 μM for homocysteine, respectively. The detection limits of cysteine and homocysteine were 0.78 and 0.67 μM, respectively. In addition, the method exhibited a high selectivity for cysteine and homocysteine over the other substances, such as amino acids, thiols, proteins, carbohydrates, etc. More importantly, the sensing system can not only achieve quantitative detection of cysteine and homocysteine but also could be applied in semiquantitative cysteine and homocysteine determination by digital visualization. Therefore, as a proof-of-concept, the proposed method has potential application for the selective detection of cysteine and homocysteine in biological fluids.  相似文献   

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