基于石墨烯量子点的荧光传感器的构建及应用

发布时间：2018-01-20 12:25

本文关键词： 石墨烯量子点柠檬黄抗坏血酸谷胱甘肽荧光传感　出处：《郑州大学》2016年硕士论文　论文类型：学位论文

【摘要】：石墨烯量子点(Graphene quantum dot,GQDs)是石墨烯家族中的最新成员,也是近三年来发展起来的一种准零维的纳米荧光材料。和传统的半导体量子点相比,GQDs具有生物相容性好,毒性低,光学性质稳定等优异的性能,在荧光传感、细胞标记以及生物成像等方面具有广阔的应用前景。然而,目前基于GQDs的荧光传感分析仍处于初级阶段,在报道的文献中存在荧光量子产率低,荧光传感敏感度低,选择性差等问题。因此,改进合成条件和传感体系的设计,以及构建高灵敏度和高选择性的GQDs传感器是非常重要的。本研究合成了GQDs和氮掺杂的石墨烯量子点(N-GQDs),基于内滤光效应,以及荧光共振能量转移两种荧光猝灭方式,分别构建了基于GQDs的柠檬黄荧光传感体系和基于N-GQDs的抗坏血酸(Ascorbic Acid,AA)和谷胱甘肽(Glutathion,GSH)的荧光传感体系,所获结果对于GQDS在荧光传感体系的应用和三种目标物的分析提供了方法学的参考和依据。具体内容如下:1.基于GQDs荧光传感法测定柠檬黄(tartrazine)利用Hummer法,通过浓硫酸和高锰酸钾对石墨在高温条件下的氧化剥离,合成GO;采用TOP-down的合成策略,以获得的GO为碳源,浓氨水(浓NH3·H2O)为碱性介质,在高温高压条件下(200℃反应5 h),使GO去氧化并断裂成尺寸较小的GQDs,利用红外光谱(IR)和透射电镜(TEM)等对获得的GQDs进行了表征。该GQDs在440 nm具有较强的荧光,与柠檬黄的吸收光谱具有较大程度的重叠,基于二者之间的内滤光效应,建立了柠檬黄的荧光传感分析新方法。在最优的实验条件下,柠檬黄的加入量与体系荧光的猝灭在0.008μmol/L~4μmol/L呈线性关系,检出限为0.0035μmol/L,相对于报道的方法,该方法具有更灵敏的检测限和更高的选择性。常见的金属离子和色素不干扰体系的测定,该方法可成功用于饮料中柠檬黄的测定。2.基于N-GQDs-MnO_2荧光off-on法测定抗坏血酸(AA)采用Down-TOP的合成策略以柠檬酸为碳源,氨水为氮源,水热法200℃反应3 h,合成了N-GQDs,通过IR,X射线电子能谱(XPS),TEM等对合成的N-GQDs进行了表征;通过Na2SO_3还原KMnO_4合成了MnO_2纳米片,MnO_2纳米片在N-GQDs发射峰处具有较宽范围的光吸收,并且和N-GQDs之间具有较强的π-π堆积作用,二者之间发生共振能量转移,从而猝灭N-GQDs的荧光;AA具有较强的还原性,可以将MnO_2纳米片还原为Mn2+,从而使得体系的荧光恢复,基于此,建立了检测AA的荧光传感新方法,AA的加入量在0.02μmol/L~8μmol/L范围内与体系荧光的恢复呈线性关系,检测限5.6 nmol/L。相对于报道的方法,该方法不仅具有最高的检测灵敏度,而且可以消除生物血样中常见干扰物尿酸(UA)、多巴胺(DA)、谷胱甘肽(GSH)的干扰,该方法成功用于血样中AA的检测,加标回收率在96.5-102.7%之间。3.基于N-GQDs-MnO_2荧光off-on法测定谷胱甘肽(GSH)在上一章合成的N-GQDs的基础上,以2-(N-吗啡啉)乙磺酸为还原剂合成MnO_2纳米片,MnO_2纳米片通过π-π堆积,与N-GQDs发生共振能量转移,N-GQDs荧光猝灭,还原型的GSH能够将MnO_2还原成Mn2+,从而使得体系的荧光恢复。基于此,建立了检测GSH的荧光传感新方法,相对于Na2SO_3还原合成的MnO_2纳米片来说,该荧光能量转移体系对GSH具有更高的选择性。在0.02~8μmol/L浓度范围内,GSH的加入量与体系的荧光恢复成线性关系,检测限为16 nmol/L,常见的金属离子、氨基酸,UA和DA不干扰GSH的测定,该方法成功的用于血样中GSH的检测,回收率在95.2-103.8%之间。
[Abstract]:Graphene quantum dots (Graphene quantum, dot, GQDs) is the newest member of the family of graphene, a quasi zero dimensional nano fluorescent material is developed in three years. Compared with traditional semiconductor quantum dots, GQDs has good biocompatibility, low toxicity, stable optical properties and excellent performance in fluorescence sensing, and has wide application prospect cell markers and biological imaging. However, the fluorescence sensing analysis based on GQDs is still in the primary stage, reported in the literature have low fluorescence quantum yield and fluorescence sensing sensitivity is low, the problem of poor selectivity. Therefore, the improved design of synthesis conditions and sensing system, and the construction of high sensitivity and high selectivity of GQDs sensor is very important. The graphene quantum dots GQDs and nitrogen doped were synthesized in this study (N-GQDs), based on the inner filter effect, and fluorescence resonance energy transfer Two fluorescence quenching method, were constructed based on Huang Yingguang lemon sensing system based on N-GQDs GQDs and ascorbic acid (Ascorbic Acid AA) and glutathione (Glutathion, GSH) the fluorescence sensing system, the analysis of the results for the application of GQDS in fluorescence sensing system and three kinds of objects provide methodological reference and the specific contents are as follows: 1.. Based on the determination of lemon yellow fluorescence sensing method based on GQDs (tartrazine) by using Hummer method, by concentrated sulfuric acid and Potassium Permanganate on oxidation stripping, under the condition of high temperature graphite synthesis GO; synthetic strategy of TOP-down, to obtain the GO as carbon source, ammonia (concentrated NH3 - H2O) for in alkaline medium, under high pressure and high temperature (200 DEG C, the reaction of 5 h) to GO oxidation and broken into smaller size GQDs, using infrared spectroscopy (IR) and transmission electron microscopy (TEM) to obtain GQDs were investigated. The GQDs in 440 nm There is a strong fluorescence, with a greater degree of overlap with the absorption spectrum of lemon yellow, the inner filter effect between the two based on the established fluorescence sensing tartrazine analysis methods. Under the optimal conditions, the amount of lemon yellow fluorescence quenching system and a linear relationship in the 0.008 mol/ L~4 mol/L, the detection limit was 0.0035 mol/L, compared with the reported methods, this method has a detection limit of more sensitive and higher selectivity. Common metal ions do not interfere with the determination of pigment and system, this method can be successfully used for the determination of lemon yellow beverage in.2. based on N-GQDs-MnO_2 off-on fluorescence method for the determination of ascorbic acid (AA) synthesis by Down-TOP's strategy of using citric acid as carbon source, ammonia as nitrogen source, hydrothermal reacting at 200 DEG C for 3 h, N-GQDs was synthesized by IR, X ray photoelectron spectroscopy (XPS), on the synthesis of N-GQDs were characterized by the reduction of Na2SO_3 KM TEM; The synthesis of nO_4 nano MnO_2, nano MnO_2 has wide range of N-GQDs emission peak light absorption, strong stacking interaction between and N-GQDs resonance energy transfer occurs between the two, so the fluorescence quenching of N-GQDs; AA has the strong reducibility, the reduction of MnO_2 nanosheets Mn2+, which makes the system of fluorescence recovery, based on this, a new method was established for fluorescence detection of AA, the amount of AA in the 0.02 mol/L~8 mol/L range and the linear relationship between the fluorescence recovery and detection limit of 5.6 nmol/L. compared with the reported methods, this method not only has the highest detection sensitivity, but also can to eliminate the common biological blood uric acid disruptors (UA), dopamine (DA), glutathione (GSH) interference, the method was successfully used for detection of AA in a blood sample, the recovery rate was 96.5-102.7%.3. N-GQDs-MnO_2 off-o based on fluorescence labeled N method for the determination of glutathione (GSH) on the basis of a chapter on the synthesis of N-GQDs, 2- (N- morpholine) ethane sulfonic acid as reducing agent synthesis of nano MnO_2, nano MnO_2 by tt-tt stacking, resonance energy transfer and fluorescence quenching of N-GQDs, N-GQDs, GSH reduced MnO_2 can be reduced to Mn2+ thus, the fluorescence recovery system. Based on this, a new method was established for fluorescence detection of GSH, compared with Na2SO_3 reduction of MnO_2 nanosheets synthesized, the fluorescence energy transfer system has a higher selectivity to GSH. In the 0.02~8 mol/L concentration range, fluorescence amount and the recovery of the GSH system into a linear relationship, the detection limit is 16 nmol/L, metal ions, common amino acids, UA and DA do not interfere with the determination of GSH, this method has been successfully used to detect GSH in a blood sample, the recovery rate was 95.2-103.8%.

【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O657.3;TP212

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