基于碳点为探针的D-青酶胺、草甘膦和日落黄荧光检测新方法研究

发布时间：2018-10-05 11:24

【摘要】：碳纳米量子点(carbon quantum dots,CDs)作为新型的纳米材料,由于其制备方式简单多样,水溶性和稳定性好,并且具有独特的光学特性,因而在生物医学、生物成像等领域得到了广阔的应用。本文采用水热法制备了三种含氮、氧元素的碳纳米量子点,利用其荧光特性建立对D-青霉胺、草甘膦和日落黄的灵敏检测。具体研究内容如下:1.基于碳点的荧光恢复检测D-青酶胺及逻辑应用基于碳点独特的光学性质,研究并制备了一种新颖、灵敏的碳点荧光探针,成功用于人体血清样本中D-青酶胺的测定。将柠檬酸钠(0.2 g)、碳铵(0.2 g)、二次蒸馏水(10 ml)依次加入到高压不锈钢反应釜中,在180?C的烘箱中反应4小时后得到浅黄色溶液,溶液透析12小时后,冷冻干燥得到最终产品。碳点的激发波长和发射波长分别为358 nm和442 nm。其荧光强度在Hg~(2+)存在时明显降低,在加入D-青酶胺后,由于D-青酶胺和Hg~(2+)之间存在较强的亲和力,导致碳点的荧光恢复。鉴于此,我们首次设计了“AND”的逻辑门和特定的荧光探针来检测D-青酶胺。测定D-青酶胺的线性范围2.0~24.0μmol·L-1,相关系数(R2)为0.998,检出限为0.6μmol·L-1。2.基于碳点的荧光共振能量转移检测草甘膦及逻辑应用提出了基于碳点和草甘膦之间的荧光共振能量转移的新方法来检测草甘膦。用柠檬酸和Tris-HCl通过水热一步合成法制得碳点。碳点的最大激发波长为340nm,在410 nm处发出明亮的蓝色荧光,草甘膦的存在可以有效地猝灭碳点的荧光。我们利用这一现象设计了一个“AND”逻辑门。据此建立了高选择性检测草甘膦的荧光光度法。在优化的条件下,其线性范围为0.02~2.0μmol·L-1,检出限为0.6μmol·L-1。该法用于检测水样中草甘膦,结果满意。3.基于碳点的荧光共振能量转移作为检测日落黄的荧光探针于坩埚中直接将N-羟乙基乙二胺三乙酸加热得到了水溶性好、粒径大小统一的碳点。在366 nm处最大激发,在423 nm波长处发出蓝色的荧光。由于碳点和日落黄之间发生荧光共振能量转移,从而导致碳点的荧光显著猝灭。据此提出了检测日落黄的新方法,测定浓度范围从0.3到8.0μmol·L~(-1),检出限(3σ/k)达到79.6 nmol·L~(-1)。此方法成功应用于检测饮料中的日落黄含量。
[Abstract]:As a new type of nano-material, carbon nanodots (carbon quantum dots,CDs) have been widely used in biomedical, biomedical and imaging fields because of their simple preparation methods, good water solubility, good stability and unique optical properties. In this paper, three kinds of carbon nanoscale quantum dots containing nitrogen and oxygen were prepared by hydrothermal method. The sensitive detection of D- penicillamine, glyphosate and sunset yellow was established by using their fluorescence characteristics. The specific contents of the study are as follows: 1. Based on the unique optical properties of carbon spots, a novel and sensitive carbon point fluorescence probe was developed, which was successfully used for the determination of D- cyanoamine in human serum samples. Sodium citrate (0.2 g), ammonium carbonate (0.2 g), secondary distilled water (10 ml) was added to the autoclave in turn. The light yellow solution was obtained after 4 hours reaction in the oven of C, 12 hours after dialysis, the final product was obtained by freeze-drying. The excitation and emission wavelengths of carbon spots are 358 nm and 442 nm., respectively. The fluorescence intensity decreased obviously when Hg~ (2) was present. After the addition of D- cyanoamine, the fluorescence of carbon point recovered due to the strong affinity between D- cyanoamine and Hg~ (2). In view of this, we first designed a "AND" logic gate and a specific fluorescent probe to detect D-cyanoamine. The linear range for the determination of D-cyanide was 2.0 渭 mol / L ~ (-1), the correlation coefficient (R2) was 0.998, and the detection limit was 0.6 渭 mol L ~ (-1). Detection of glyphosate based on carbon Point fluorescence Resonance Energy transfer and its logical applications A new method based on fluorescence resonance energy transfer between carbon point and glyphosate is proposed to detect glyphosate. Carbon dots were prepared by hydrothermal synthesis with citric acid and Tris-HCl. The maximum excitation wavelength of the carbon point is 340 nm, and bright blue fluorescence is emitted at 410 nm. The existence of glyphosate can effectively quench the fluorescence of the carbon point. We use this phenomenon to design a "AND" logic gate. A high selective fluorescence spectrophotometric method for the determination of glyphosate was established. Under the optimized conditions, the linear range is 0.02 渭 mol L -1 and the detection limit is 0.6 渭 mol L -1. The method has been applied to the determination of glyphosate in water with satisfactory results. Fluorescence resonance energy transfer based on carbon point was used as a fluorescence probe for detecting sunset yellow in crucible to directly heat N- hydroxyethyl ethylenediamine triacetic acid to obtain a carbon point with good water solubility and uniform particle size. The maximum excitation is at 366 nm, and the blue fluorescence is emitted at 423 nm wavelength. Fluorescence resonance energy transfer occurs between carbon point and sunset yellow, which leads to fluorescence quenching of carbon point. A new method for the detection of sunset yellow is proposed. The concentration range is from 0.3 to 8.0 渭 mol L ~ (-1), and the detection limit (3 蟽 / k) is 79.6 nmol L ~ (-1). This method has been successfully applied to the determination of sunset yellow in beverage.
【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O657.3;TB383.1

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