基于碳点的新型荧光材料的合成及对金属铬的检测研究

发布时间：2018-04-27 05:32

本文选题：荧光碳点 + β-环糊精　；参考：《江苏大学》2017年硕士论文

【摘要】：荧光碳点(FCDs)是一类性能优异的新型荧光探针材料,荧光性能稳定,毒性小,并且具有较好的水溶性和生物相容性,在金属离子检测领域具有广泛的应用和研究价值。但是它们也存在一定的问题,如荧光碳点的荧光强度较弱,在检测金属离子时灵敏度和选择性有限。针对上述问题,本文探究了单独荧光碳点的合成与应用,在此基础上,设计并制备了不同系列经多糖分子(β-环糊精和壳聚糖)修饰的荧光碳点复合材料,将其用于土壤中金属离子的检测。本论文包括以下四个部分:(1)以纯棉为原料,采用一步水热法,合成了水溶性的荧光FCDs纳米材料。采用紫外-可见光谱分析(UV-vis)、红外光谱分析(FT-IR)和透射电子显微镜分析(TEM)等手段,对FCDs的结构和粒径分布进行了表征,其粒径分布为2-5nm。优化的制备FCDs条件为:水热时间温度200oC,水热时间15h,纯棉材料的使用量1.2g/70mL。探讨了FCDs浓度、pH和反应时间对检测Cr(VI)体系的荧光光谱影响,FCDs检测Cr(VI)的最佳条件为FCDs浓度为2.0×10-5g/mL、pH为6.5和反应时间为20min。FCDs与Cr(VI)体系相互作用后,其相对荧光强度(F0/F)与Cr(VI)浓度具有良好的线性关系,相关系数R2=0.9979,由此建立了FCDs定量测定金属铬的荧光分析方法。将此应用于自制水样和土壤样品中铬的含量测定,回收率分别为96.70%-99.20%和97.20%-99.80%,结果令人满意。(2)以FCDs、β-环糊精(β-CD)为原料,通过异佛尔酮二异氰酸酯(IPDI)的连接作用,成功合成了一种新型水溶性碳点-异佛尔酮二异氰酸酯-环糊精(FCDs-IPDI-CD)荧光复合材料。TEM测试结果表明,FCDs-IPDI-CD为一种腔型结构,在自然光的照射下,其水溶液为淡黄色,在紫外灯照射下呈现出明亮的蓝紫光。当FCDs-IPDI-CD的浓度为0.03g/mL,体系pH值为9.5,反应时间为20min时,Cr(VI)与FCDs-IPDI-CD体系的相对荧光强度(F0/F)与Cr(VI)浓度具有良好的线性关系,相关系数R2=0.9976,由此建立了FCDs-IPDI-CD定量测定铬的荧光分析方法。将此应用于自制水样和土壤样品中的Cr(VI)的检测,回收率分别为95.80%-99.30%和93.59%-97.34%,结果令人满意。(3)以FCDs、壳聚糖(CTS)为原料,成功合成了一种新型水溶性壳聚糖包覆的荧光碳点材料(FCDs/CTS)。TEM测试结果表明,FCDs/CTS为分散的近球形颗粒,并且由不规则的阴影包围,在自然光的照射下,其水溶液为淡黄色,在紫外灯照射下呈现出明亮的蓝紫光。当FCDs/CTS的浓度为0.02g/mL,体系pH值为8.5,反应时间为20min时,Cr(VI)与FCDs/CTS体系的相对荧光强度(F0/F)与Cr(VI)浓度具有良好的线性关系,相关系数R2=0.9970,由此建立了FCDs/CTS定量测定铬的荧光分析方法。将此应用于自制水样和土壤样品中的Cr(VI)的检测,回收率分别为95.60%-99.20%和93.52%-97.47%,结果令人满意。(4)以FCDs、CTS为原料,通过IPDI的连接作用,成功合成了一种新型水溶性碳点-异佛尔酮二异氰酸酯-壳聚糖(FCDs-IPDI-CTS)荧光复合材料。TEM测试结果表明,FCDs-IPDI-CTS为近似球形且带有不规则的阴影,在自然光的照射下,其水溶液为淡黄色,在紫外灯照射下呈现出明亮的蓝紫光。当FCDs-IPDI-CTS的浓度为0.01g/mL,体系pH值为10.5,反应时间为30min时,Cr(VI)与FCDs-IPDI-CTS体系的相对荧光强度(F0/F)与Cr(VI)浓度具有良好的线性关系,相关系数R2=0.9993,由此建立了FCDs-IPDI-CTS定量测定铬的荧光分析方法。将此应用于自制水样和土壤样品中的Cr(VI)的检测,回收率分别为96.10%-99.40%和94.27%-97.58%,结果令人满意。
[Abstract]:Fluorocarbon point (FCDs) is a new type of fluorescent probe material with excellent properties. The fluorescence properties are stable, the toxicity is small, and it has good solubility in water and biocompatibility. It has a wide application and research value in the field of metal ion detection. However, there are some questions, such as the weak fluorescence intensity of the fluorescent carbon point, and the detection of metal. The sensitivity and selectivity of ions are limited. Aiming at the above problems, this paper explores the synthesis and application of separate fluorescent carbon points. On this basis, a series of different series of fluorescent carbon dots modified by polysaccharide molecules (beta cyclodextrin and chitosan) have been designed and prepared for the detection of metal ions in soil. This paper includes the following four Part: (1) the water-soluble fluorescent FCDs nanomaterials were synthesized by one step hydrothermal method using pure cotton as raw materials. Ultraviolet visible spectrum analysis (UV-vis), infrared spectrum analysis (FT-IR) and transmission electron microscope analysis (TEM) were used to characterize the structure and particle size distribution of FCDs. The particle size distribution was 2-5nm. optimized for the preparation of FCDs strips. The thermal time temperature 200oC, the hydrothermal time 15h, the use of the pure cotton material 1.2g/70mL. discussed the FCDs concentration, pH and the reaction time influence the fluorescence spectrum of the Cr (VI) system. The optimum condition for the FCDs to detect Cr (VI) was the FCDs concentration of 2 * 10-5g/mL, and the reaction time was 6.5 and the reaction time was interacted with the system. The fluorescence intensity (F0/F) has a good linear relationship with the concentration of Cr (VI), and the correlation coefficient is R2=0.9979. Thus, a fluorescence analysis method for the quantitative determination of metal chromium by FCDs is established. This method is applied to the determination of chromium content in self-made water samples and soil samples, and the recovery rate is 96.70%-99.20% and 97.20%-99.80% respectively. (2) FCDs, beta cyclodextrin is used. (beta -CD) as a raw material, a new water-soluble carbon point - isophorone diisocyanate diisocyanate - cyclodextrin (FCDs-IPDI-CD) fluorescent composite was synthesized by the connection of isophorone diisocyanate (IPDI). The results showed that FCDs-IPDI-CD was a cavity type structure. Under natural light, the aqueous solution was yellowish yellow and purple. When the concentration of FCDs-IPDI-CD is 0.03g/mL, the pH value of the system is 9.5 and the reaction time is 20min, the relative fluorescence intensity (F0/F) of Cr (VI) and FCDs-IPDI-CD system has a good linear relationship with Cr (VI), and the correlation coefficient is R2= 0.9976. Thus the fluorescence analysis of the quantitative determination of chromium by FCDs-IPDI-CD is established. Methods. The results were applied to the detection of Cr (VI) in self-made water samples and soil samples. The recovery rates were 95.80%-99.30% and 93.59%-97.34%, and the results were satisfactory. (3) a new water-soluble chitosan coated fluorescent carbon point material (FCDs/CTS).TEM test results were successfully synthesized with FCDs and CTS as raw materials. The results showed that FCDs/CTS was dispersed. Near spherical particles, surrounded by irregular shadows, under the light of natural light, the aqueous solution is light yellow and bright blue violet light under ultraviolet light. When the concentration of FCDs/CTS is 0.02g/mL, the pH value of the system is 8.5, the reaction time is 20min, the relative fluorescence intensity (F0/F) and Cr (VI) of Cr (VI) and FCDs/ CTS system are good. Good linear relationship and correlation coefficient R2=0.9970, thus a method for the quantitative determination of chromium by FCDs/CTS was established. This method was applied to the detection of Cr (VI) in self-made water samples and soil samples. The recovery rate was 95.60%-99.20% and 93.52%-97.47% respectively. (4) FCDs, CTS as raw material, and the joint effect of IPDI was successfully synthesized. A new type of water-soluble carbon point - isophorone diisocyanate - chitosan (FCDs-IPDI-CTS) fluorescence composite material.TEM test results show that FCDs-IPDI-CTS is approximately spherical and with irregular shadow. Under the light of natural light, its aqueous solution is light yellow and bright blue violet light under ultraviolet light. When FCDs-IPDI-CTS is strong. When the degree is 0.01g/mL, the system pH value is 10.5 and the reaction time is 30min, the relative fluorescence intensity (F0/F) of Cr (VI) and FCDs-IPDI-CTS system has a good linear relationship with the concentration of Cr (VI), and the correlation coefficient is R2=0.9993. Thus, the fluorescence segregation method of the FCDs-IPDI-CTS quantitative determination of chromium is established. The recoveries were 96.10%-99.40% and 94.27%-97.58% respectively, and the results were satisfactory.

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

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