荧光掺杂碳点的制备、表征及其应用研究

发布时间：2018-02-08 11:09

本文关键词： 硼氮共掺杂碳点氮硫共掺杂碳点汞离子姜黄素还原型谷胱甘肽　出处：《山西医科大学》2017年硕士论文　论文类型：学位论文

【摘要】：目的:荧光碳点(CDs)作为一种新型的碳纳米材料因具有优良的光学性能、优越的生物相容性、良好的水溶性、较低的细胞毒性等优点被广泛用于荧光探针、光催化剂、生物成像和荧光化学传感器等领域。虽然碳点的优点很多,但是传统的碳点荧光量子产率相对较低,极大限制了其在化学传感、药物载体、生物成像等领域的发展。研究者们利用各种方法来提高碳点的量子产率,发现将N、S、P等杂原子与碳点掺杂可以有效提高碳点的量子产率。因此,制备高量子产率的掺杂碳点并开发其在分析测试中的应用具有现实意义。方法:本文利用微波加热法成功制备了硼氮共掺杂碳点(BNCDs)和氮硫共掺杂碳点(NSCDs)。通过透射电镜(TEM)、X射线衍射法(XRD)、傅里叶变换红外光谱(FT-IR)、X射线光电子能谱(XPS)等技术对这两种掺杂碳点的形状、粒径大小、官能团及元素组成等进行了表征。利用紫外-可见吸收光谱(UV-Vis)和荧光光谱考察了掺杂碳点的光学性质。BNCDs的荧光强度随着溶液中Hg~(2+)或姜黄素浓度的增加显著降低,利用此现象分别建立了检测Hg~(2+)和姜黄素的方法。基于Hg~(2+)对NSCDs荧光猝灭及还原型谷胱甘肽(GSH)使NSCDs-Hg~(2+)体系荧光恢复的特性,建立了检测GSH的“开关”型(turnoff/on)荧光探针。结果:分别对BNCDs和NSCDs的形态、元素组成及官能团进行了表征。以BNCDs为荧光探针,对Hg~(2+)和姜黄素进行了定量测定。Hg~(2+)的检出限(LOD)是2.3nM,线性范围是0.04～22.00 μM。此外,姜黄素的检出限和线性范围分别为65 nM、0.2～12.5 μM。该方法被成功用于自来水和湖水样品中Hg~(2+)的测定,加标回收率在99.8～101.8%之间。对尿样和血样中姜黄素的含量进行了测定,回收率是96.5～105.5%。我们还构建了一种基于NSCDs的“开关”型荧光探针,实现了 GSH的微量测定。向NSCDs溶液中引入Hg~(2+)后,NSCDs荧光明显被猝灭,此时NSCDs-Hg~(2+)体系处于荧光“关闭”的状态。向NSCDs-Hg~(2+)体系加入GSH溶液后,NSCDs荧光得到恢复,此时体系处于荧光“打开”的状态,这一过程可用于GSH的测定,检出限为52 nM,线性范围是0.5～34.0μM。结论:基于Hg~(2+)和姜黄素对BNCDs荧光的猝灭,分别建立了实际水样中Hg~(2+)和实际样品中姜黄素的检测方法。初步推断Hg~(2+)对BNCDs的荧光猝灭主要为静态猝灭过程,姜黄素对BNCDs荧光猝灭主要是内滤光效应和动态猝灭。利用Hg~(2+)使NSCDs荧光猝灭和GSH对NSCDs-Hg~(2+)体系荧光恢复的过程,构建了“开关”型荧光探针,用于实际尿样和血样中GSH的检测,获得满意的结果。探讨了 NSCDs荧光猝灭和恢复的机理。Hg~(2+)与NSCDs相互作用的过程主要为动态猝灭。由于GSH对Hg~(2+)的亲和力很强,向NSCDs-Hg~(2+)体系加入GSH后,GSH与Hg~(2+)形成稳定的配合物,从而使NSCDs荧光得到恢复。
[Abstract]:Objective: as a new carbon nanomaterial, fluorescent carbon dots (CDS) have been widely used as fluorescent probes and photocatalysts for their excellent optical properties, excellent biocompatibility, good water solubility and low cytotoxicity. Although the advantages of carbon dots are many, the fluorescence quantum yields of traditional carbon dots are relatively low, which greatly limits their applications in chemical sensing, drug carriers, and so on. The researchers used various methods to improve the quantum yield of carbon dots, and found that doping hetero atoms such as Nu Schip with carbon dots can effectively improve the quantum yield of carbon dots. It is of practical significance to prepare doped carbon dots with high quantum yield and to develop their applications in analysis and measurement. Methods: in this paper, boron nitrogen co-doped carbon dots (BNCDs) and nitrogen-sulfur co-doped carbon dots (NSCDss) were successfully prepared by microwave heating. The shape of the two doped carbon spots was studied by means of electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The size of particle size, functional group and elemental composition were characterized. The optical properties of the doped carbon sites were investigated by UV-Visand fluorescence spectra. The fluorescence intensity of the doped carbon dots decreased with the increase of Hg~(2) or curcumin concentration in the solution. Using this phenomenon, a method for the detection of Hg~(2) and curcumin was developed. The fluorescence quenching of NSCDs and the fluorescence recovery of NSCDs-Hg~(2 by reduced glutathione (Glutathione) were based on Hg~(2. A "switch" fluorescence probe for the detection of GSH was established. Results: the morphology, elemental composition and functional groups of BNCDs and NSCDs were characterized, respectively. BNCDs was used as fluorescence probe. The detection limit of Hg~(2) and curcumin was 2.3nM and the linear range of curcumin was 0.04 ~ 22.00 渭 M. in addition, the detection limit and linear range of curcumin were 65 nm ~ 0.2n ~ (12.5 渭 m), respectively. The method has been successfully applied to the determination of Hg~(2 in tap water and lake water samples. The recoveries of curcumin in urine and blood samples were determined in the range of 99.8 ~ 101.8%. The recoveries of curcumin in urine and blood samples were 96. 5 ~ 105.5%. We also constructed a "switch" fluorescent probe based on NSCDs. The microdetermination of GSH was realized. The fluorescence of GSH was obviously quenched after the introduction of Hg~(2 into NSCDs solution, and the fluorescence of NSCDs-Hg~(2) system was in the state of "off". The fluorescence of NSCDs was recovered after adding GSH solution to the NSCDs-Hg~(2 system. This process can be used for the determination of GSH with a detection limit of 52 nm and a linear range of 0.5 渭 m ~ 34.0 渭 M. conclusion: based on Hg~(2) and curcumin, the fluorescence of BNCDs can be quenched. Methods for the determination of curcumin in real water samples and curcumin samples were established respectively. The fluorescence quenching of BNCDs by Hg~(2) was mainly a static quenching process. The fluorescence quenching of BNCDs by curcumin was mainly internal filter effect and dynamic quenching. By using Hg~(2 to quench the fluorescence of NSCDs and GSH to restore the fluorescence of NSCDs-Hg~(2) system, a "switch" fluorescence probe was constructed for the detection of GSH in real urine and blood samples. The mechanism of fluorescence quenching and recovery of NSCDs was studied. The process of interaction between GSH and NSCDs was mainly dynamic quenching. Because of the strong affinity of GSH to Hg~(2), the NSCDs-Hg~(2) system was added to GSH to form a stable complex. Thus, the fluorescence of NSCDs was restored.
【学位授予单位】：山西医科大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O657.3;TB383.1

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