基于氧化锌量子点双比色荧光传感器检测炭疽生物标记物的研究

发布时间：2018-02-28 18:16

本文关键词： 氧化锌量子点炭疽芽孢杆菌吡啶二羧酸钙双比色荧光传感器　出处：《郑州大学》2017年硕士论文　论文类型：学位论文

【摘要】：氧化锌量子点是一种新型的荧光纳米传感器,其颗粒粒径小、发光强度高、光稳定性好、生物毒性低,制备简便及生产成本低等优异特性,同时具有水溶性在生物荧光成像,生物荧光探针及载药等许多领域具有广阔的应用前景。炭疽芽孢杆菌作为潜在的生化武器严重威胁人类的生命健康,目前探测其存在的方法多种多样,而镧基荧光光谱法被广泛推广,该方法基于芽孢杆菌的生物标志物Ca DPA可有效敏化稀土离子的荧光发射,同时稀土离子具有窄的发射谱、发光寿命长的原理。铕(Eu)和铽(Tb)是荧光传感器中常用的镧系元素离子,它们具有强的荧光,长的荧光寿命及尖锐的线状发射带。Eu3+的最强发射位于616 nm,该本征发射将不会受到530 nm处的Zn O QDs荧光发射的干扰,而544 nm处的Tb3+的本征发射峰与Zn O QDs的发射带有重叠,同时Eu3+的红色荧光也易于肉眼观察。再次铕基荧光传感器可有效降低芳香族化合物与Tb3+的结合而造成的假阳性结果。迄今为止,以氧化锌量子点作为内在参比荧光检测炭疽芽孢杆菌研究尚未报道。综上我们将选用铕离子与氧化锌量子点结合,铕离子作为传感单元,氧化锌量子点作为参比单元,以制备性能优异的双比色荧光传感器,实现对炭疽芽孢杆菌的快速,灵敏高选择性的检测。本文所取得的研究成果如下:1)成功制备了六方纤锌矿结构的氧化锌量子点,其平均颗粒粒径~5 nm,具有良好的水溶性,强的黄光发射,高量子产率(31.98%)及良好的发光稳定性。同时氧化锌量子点本身具有较低的生物毒性,制备简便,生产成本低等优质的特性。该氧化锌量子点表面带有-NH2基团易于表面改性以设计开发性能优异的纳米荧光探针,在生物医学成像、疾病诊断和治疗等方面起着至关重要的作用。2)成功制备一种铕修饰的氧化锌量子点纳米结构(Zn O/Eu),用于快速、灵敏的双比色检测炭疽芽孢杆菌的存在。具有高强黄色荧光发射的氧化锌量子点作为一种内在参比,铕离子(Eu3+)螯合在氧化锌量子点的表面作为信号报告单元。当铕离子与芽孢杆菌的生物标志物Ca DPA配位后其红色荧光强度将显著增强,而氧化锌量子点的黄色荧光却保持不变,因此增加的Ca DPA浓度可以导致Zn O/Eu杂化纳米结构的两种荧光强度比的变化。同时由于制备的氧化锌量子点的吸收带延伸到深紫外区,覆盖DPA在280 nm处的吸收峰,可实现氧化锌量子点与DPA在同一激发波长(280 nm)下的共同激发,所以该ZnO/Eu纳米结构有望实现对CaDPA的双比色荧光检测。3)该传感器时间响应曲线展示传感反应可在~8 s内完成,从而能够快速检测炭疽芽孢杆菌孢子的存在。在同一激发波长下,该传感器中氧化锌量子点和Eu3+的发光强度比值(I616/I530)与Ca DPA在0~4μM浓度范围内呈良好的线性关系,使其能实现对微量浓度的Ca DPA进行定量测定,同时通过IUPAC方法计算Zn O/Eu纳米结构对Ca DPA的检测极限为3 n M,此检测极限远低于人体对炭疽芽孢杆菌感染剂量(60μM)。比率荧光测试也有效降低外界环境的干扰,以提升检测结果的准确性。增大Ca DPA的浓度该传感器在紫外灯照射下溶液颜色由黄色过渡到红色,因人眼对颜色变化敏感,该传感器也利于裸眼检测Ca DPA的浓度。最后该比率荧光传感器对Ca DPA显示出比其它芳族配体,氨基酸和常见细胞离子具有显着的选择性。因此快速地响应、良好的灵敏度及选择性使得Zn O/Eu纳米结构在检测炭疽细菌中提供了有效便捷的方式,在临床分析中具有巨大的应用潜力。
[Abstract]:Zinc Oxide is a new type of quantum dot fluorescent nano sensor, its small particle size, high luminous intensity, good light stability, low toxicity and low production cost, simple preparation and excellent properties, it is soluble in water in biological fluorescence imaging, and has broad application prospects in biological fluorescent probes and drug loading and many other fields Bacillus anthracis. As a potential biological weapon serious threat to human life and health, the current detection methods are varied, and the lanthanum based fluorescence spectroscopy has been widely popularized, the method based on Bacillus biomarker fluorescence emission Ca DPA can effectively sensitized, and rare earth ions having narrow emission spectra. The principle of luminescence and long life. (Eu) europium and terbium (Tb) fluorescent sensor lanthanide ions commonly used, they have strong fluorescence, long fluorescence lifetime and sharp linear emission band.Eu3+ The strongest emission at 616 nm, the intrinsic emission will be at 530 nm Zn O QDs fluorescence emission interference, and the intrinsic emission peak and Zn O QDs emission at 544 nm Tb3+ with red fluorescence overlap, while the Eu3+ is easily observed. Again based europium fluorescent sensors can have false positive the effect of reduced binding of aromatic compounds and Tb3+ caused. So far, Zinc Oxide quantum dots as internal reference fluorescence detection of Bacillus anthracis research have not been reported yet. So we will choose europium ion and Zinc Oxide quantum dots with europium ion as a sensing unit, Zinc Oxide quantum dots as a reference cell, producing excellent performance dual color fluorescence sensor for realization of Bacillus anthracis, rapid, sensitive and highly selective detection. The results of this study are as follows: 1) Zinc Oxide six quantum wurtzite structure were prepared Point, the average particle size of ~5 nm, has good water solubility, strong yellow emission, high quantum yield (31.98%) and good luminescent stability. At the same time Zinc Oxide quantum dot itself has low toxicity, easy preparation, low production cost and good quality. The surface of the quantum dots with Zinc Oxide -NH2 group of easy surface modification for the design of nano fluorescent probe excellentperformance, in biomedical imaging, plays a crucial role in.2 disease diagnosis and treatment) were prepared by Zinc Oxide quantum dot nanostructures for europium were successfully modified (Zn, O/Eu) for rapid, sensitive double colorimetric detection of Bacillus anthracis there is Zinc Oxide quantum dots. High strength yellow fluorescence emission as an internal reference, europium (Eu3+) chelate on the surface of Zinc Oxide quantum dots as a signal unit. When the report of europium ion and Bacillus biomarkers The red fluorescence intensity will be significantly enhanced Ca DPA markers after coordination, while Zinc Oxide yellow fluorescent quantum dots has remained unchanged, so Ca increased DPA concentration can lead to changes of two kinds of fluorescence intensity of Zn O/Eu hybrid nanostructures. At the same time as Zinc Oxide than quantum dots prepared by extending to the deep ultraviolet absorption band DPA, covered in the peak of 280 nm, Zinc Oxide and DPA can realize quantum dots at the same excitation wavelength (280 nm) under the common excitation, so the ZnO/Eu nano structure is expected to achieve the CaDPA dual color fluorescence detection.3) the sensor response time curve display sensing reaction can be completed in ~8 s thus, rapid detection of Bacillus anthracis spores. At the same excitation wavelength, emission intensity ratio of quantum dots and the Zinc Oxide Eu3+ sensor (I616/I530) and Ca DPA in 0~4 M concentration range showed a good linear relationship The system can realize the trace concentrations of Ca DPA were measured and calculated by the IUPAC method, the detection limit of Zn O/Eu nano structure of Ca DPA 3 N M, the detection limit is far lower than the human dose infection of Bacillus anthracis (60 M). The fluorescence test also effectively reduce interference ratio of low external environment in order to improve the accuracy of the test results. The increase of the concentration of Ca DPA in the sensor solution under the irradiation of ultraviolet light color from yellow to red transition, because of the human eye to color sensitive to changes in concentration of the sensor to the naked eye detection of Ca DPA. Finally, the ratio of fluorescence sensor for Ca DPA than other aromatic ligand, amino acids and common cell ions have significant selectivity. Therefore, fast response, good sensitivity and selectivity makes Zn O/Eu nanostructures in the detection of anthrax bacteria provides effective and convenient way in clinical analysis It has great potential for application.

【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O657.3

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