水热法合成碳量子点及作为荧光传感器的应用

发布时间：2018-05-02 02:49

本文选题：碳量子点 + 绿色合成　；参考：《山西大学》2017年硕士论文

【摘要】：碳量子点(CQDs)作为碳纳米材料家族的后起之秀,因其原材料广、成本低廉、光学性能稳定、生物相容性好、制备方法多样等优势,在研究初期便受到了广泛的关注。近几年,CQDs作为荧光纳米传感器对金属阳离子或有机小分子的识别与检测方面仍是研究热点。本论文采用一步水热法合成了三种蓝色荧光CQDs,对其形貌进行了表征,测试了其光谱性质,分别实现了其对苦味酸(PA)、pH、和Fe~(3+)/抗坏血酸(AA)的分析检测。第一章:简要概述了CQDs的合成、光学性质、及作为荧光纳米传感应用方面的研究进展。第二章:以香蕉汁为绿色碳源,采用简单、经济的一步水热法合成了水溶性好,稳定性高的蓝色荧光CQDs。通过X射线衍射(XRD)、透射电镜(TEM)、傅立叶红外光谱(FT-IR)、紫外-可见吸收光谱(UV-vis)、及荧光光谱(FL)等方法对CQDs的形貌、结构以及光谱性能进行了表征。研究发现,苦味酸(PA)对该CQDs荧光具有猝灭作用,其猝灭程度与PA浓度在0.5~30.4μM的范围内呈良好的线性关系,检出限为94.8nM(S/N=3)。该方法可用于实际样品中PA的测定,方法回收率为96.4%~101.4%。通过紫外吸收光谱和荧光寿命衰减曲线的变化确定了二者的猝灭类型为静态猝灭。第三章:以柳絮为绿色碳源,通过一步水热法合成出蓝色CQDs。该CQDs的荧光量子产率(QY)为4.93%,荧光寿命为3.322ns。基于该CQDs对pH的敏感响应,构建了可逆pH传感体系。该pH传感不受离子强度,金属离子的影响。该CQDs的荧光强度在pH值6-12的范围内呈现良好的线性关系,其线性回归方程为F=-138.81pH+1736.64,相关系数R2为0.994。采用本法测定了当地自来水和汾河水中pH值,结果满意。第四章:以天然产物黑芝麻为原料,采用水热法一步合成了稳定发蓝光的CQDs。在Fe~(3+)存在下,该水溶性CQDs的荧光有显著猝灭现象,加入抗坏血酸(AA)后对Fe~(3+)有还原作用,使CQDs-Fe~(3+)体系的荧光猝灭产生一定程度的恢复行为,且恢复程度与AA的浓度呈线性关系。基于CQDs的这种荧光“关-开”现象,建立了对Fe~(3+)和AA具有选择性响应的Turn-on型荧光传感分析技术。该方法Fe~(3+)和AA的线性范围分别为50-1500μM和32.2-987.6μM。Fe~(3+)和AA的检出限分别为2.78μM和0.0344μM。第五章:对本论文的工作进行了简要总结,并对CQDs面临的挑战和下一步研究方向做出了展望。
[Abstract]:Carbon Quantum Dots (CQDs), as a rising star of carbon nanomaterial family, has attracted wide attention in the early stage of research because of its advantages of wide raw materials, low cost, stable optical properties, good biocompatibility and various preparation methods. In recent years, CQDs as a fluorescent nanosensor for the recognition and detection of metal cations or organic small molecules is still a research hotspot. In this paper, three kinds of blue fluorescent CQDswere synthesized by one step hydrothermal method. Their morphology was characterized, their spectral properties were tested, and the pH of picric acid and Fe~(3 / ascorbic acid were determined. Chapter 1: the synthesis, optical properties and applications of CQDs as fluorescent nanosensors are briefly reviewed. In chapter 2, using banana juice as green carbon source, blue fluorescent CQDs with good water solubility and high stability were synthesized by a simple and economical one step hydrothermal method. The morphology, structure and spectral properties of CQDs were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), UV-vis (UV-vis) and fluorescence spectroscopy (CQDs). It was found that the fluorescence of CQDs was quenched by picric acid (PAA), and the quenching degree was linear with the concentration of PA in the range of 0.5 渭 m and 30.4 渭 M. the detection limit was 94.8 nMN / N ~ (3 +). The method can be applied to the determination of PA in practical samples. The recovery of the method is 96. 4% and 101.4%. According to the change of UV absorption spectrum and fluorescence lifetime decay curve, the quenching type of them is static quenching. Chapter 3: blue CQDs were synthesized by one step hydrothermal method with catkins as green carbon source. The fluorescence quantum yield (QY) of the CQDs is 4.93 and the fluorescence lifetime is 3.322 ns. Based on the pH sensitivity of the CQDs, a reversible pH sensing system was constructed. The pH sensor is not affected by ionic strength and metal ions. The fluorescence intensity of the CQDs shows a good linear relationship in the range of pH 6-12. The linear regression equation is F=-138.81pH 1736.64, and the correlation coefficient R2 is 0.994. The pH value of local tap water and Fenhe river water was determined by this method with satisfactory results. Chapter 4: using black sesame as raw material, CQDs with stable blue light were synthesized by hydrothermal method. In the presence of Fe~(3, the fluorescence of the water-soluble CQDs was significantly quenched. After adding ascorbic acid (AAA), the Fe~(3) was reduced to a certain extent, and the fluorescence quenching of the CQDs-Fe~(3) system was induced to a certain extent. The degree of recovery was linear with the concentration of AA. Based on the "turn-on" phenomenon of CQDs, a Turn-on type fluorescence sensing technique with selective response to Fe~(3 and AA was established. The linear ranges of Fe~(3 and AA are 50-1500 渭 M and 32.2-987.6 渭 M.Fe~(3, respectively. The detection limits of AA are 2.78 渭 M and 0.0344 渭 M, respectively. Chapter 5: this paper briefly summarizes the work of this paper, and the challenges faced by CQDs and the future research direction are prospected.
【学位授予单位】：山西大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O657.3

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