纤维素基荧光碳点的制备及其应用研究

发布时间：2018-01-21 04:27

  本文关键词： 碳点 纤维素 生物成像 Fe(Ⅲ)检测　出处：《浙江理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：碳点(CDs)是一种尺寸小于10 nm的新型荧光纳米粒子,自2004年CDs被报道以来,已经吸引了广大科研工作者的兴趣和关注。CDs具有极好的生物相容性、优秀的荧光性能、稳定的化学和物理性质、低毒性、极佳的水溶性等性质,大大拓展了CDs的应用领域和范围。目前,CDs的制备方法主要有,激光蚀刻法,电化学法,模板法等,这些方法存在原料价格高,设备价格昂贵或者实验操作复杂等缺陷,因此,急需一种操作简单,原料便宜同时可提高碳点荧光量子产率的制备方法。提高CDs荧光量子产率的方法一般有两种,一种是后期对CDs进行表面钝化;另一种是掺杂杂原子。为了进一步降低制备成本,改善CDs的荧光性能,本课题选择以廉价易得可降解的生物质基—纤维素为原料,掺杂氮硫杂原子,通过一步水热法制得一系列纤维素基荧光CDs,分别对制得的CDs进行最适实验条件探究,形貌表征,成分和性能分析,通过细胞毒性试验评价其毒性,并将它们应用于生物成像与在溶液中对Fe(Ⅲ)检测,并对Fe(Ⅲ)检测下限和检测机理进行探究最终得到实验结论如下:(1)氮掺杂纤维素基荧光CDs的制备及在生物成像的应用研究:以纤维素粉和尿素为原料,通过绿色环保的水热法一步制备了氮掺杂纤维素基荧光CDs(N-CDs)。考察了尿素质量、反应时间和反应温度对N-CDs荧光量子产率的影响,并探究最适实验条件为:尿素与纤维素的质量比为0.7,反应温度为180°C,反应时间为72 h,此时N-CDs的荧光量子产率达21.7%;对N-CDs的形貌、成分和光学性能进行表征与分析,发现它的平均尺寸为4.2 nm,表面存在氨基、羟基等基团,具有依赖激发光波长的荧光性质;通过细胞毒性试验,发现N-CDs的细胞存活率达89%以上,并将其成功应用于细胞成像。(2)氮硫共掺杂纤维素基荧光CDs的制备及在生物成像的应用研究:以纤维素粉、硫代硫酸钠和乙二胺(EDA)为原料,通过绿色环保的水热法一步制备了氮硫共掺杂纤维素基荧光CDs(N,S-CDs)。N,S-CDs的最适实验条件为:纤维素粉0.5 g,硫代硫酸钠0.1 g,乙二胺0.5 mL,反应时间72 h,反应温度180°C,此时他的荧光量子产率达28.2%;并对N,S-CDs的形貌、成分和光学性能进行表征与分析,发现它的平均尺寸为3.2 nm,存在氨基,羟基和含硫基团等基团,具有依赖激发光波长的荧光性质;相较于N-CDs,N,S-CDs具有更高的荧光量子产率,相同激发光下的N,S-CDs发射光发生红移;通过细胞毒性试验,发现N,S-CDs的细胞存活率达93%以上,并将其成功应用于细胞成像。(3)纤维素基荧光CDs在溶液中对Fe(Ⅲ)检测的应用研究:将Cellulose-CDs,N-CDs,N,S-CDs和EDA-CDs分别在PBS缓冲液和水溶液当中进行Fe(Ⅲ)检测。并对N,S-CDs和EDA-CDs分别在PBS缓冲液和水溶液中进行Fe(Ⅲ)检测下限的测定,分别为0.3119 ppm和0.03378 ppm,对其检测机理进行探究。
[Abstract]:Carbon dots (CDs) is a new type of fluorescent nanoparticles with size less than 10 nm, which has been reported since 2004. CDs have attracted the interest and attention of many researchers. CDs have excellent biocompatibility, excellent fluorescence properties, stable chemical and physical properties, low toxicity, excellent water solubility and so on. At present, the main preparation methods of CDs are laser etching, electrochemical method, template method and so on. These methods have high raw material price. The equipment is expensive or the experiment operation is complex, so it is urgent to have a simple operation. The method of preparing carbon dot fluorescence quantum yield can be improved by cheap raw material. There are two methods to improve CDs fluorescence quantum yield, one is to passivate the surface of CDs in the later stage; In order to further reduce the cost of preparation and improve the fluorescence properties of CDs, we choose biodegradable biomass-based cellulose as the raw material, doped nitrogen and sulfur hetero atoms. A series of Cellulose based fluorescent CDs were obtained by one step hydrothermal method. The optimal experimental conditions, morphology characterization, composition and performance analysis of the CDs were studied, and the toxicity was evaluated by cytotoxicity test. They were applied to biometric imaging and detection of Fe (鈪，

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