氧化钼量子点的制备及其应用研究

发布时间：2018-07-06 09:02

本文选题：氧化钼量子点(MoO_x + QDs)　；参考：《东华理工大学》2017年硕士论文

【摘要】：氧化钼纳米材料因其卓越的光学、电学、催化和机械性能,在基础科学研究中引起了科研工作者们极大的兴趣。目前,人们已经合成了不同形貌的氧化钼纳米材料并在生物化学传感、催化、锂离子电池等方面取得了很大的进展。然而,现有的氧化钼纳米材料合成方法或操作步骤繁琐、或耗时长、或反应条件苛刻、或使用有机溶剂。同时,具有荧光的氧化钼纳米材料鲜有报道,更未曾作为荧光探针应用于化学和生物传感。因此,开发一种快速、环保且可大规模合成荧光氧化钼纳米材料的方法仍具有很大的挑战。基于此,本文合成了具有荧光的氧化钼量子点(MoO_x QDs),并将其作为一种新型的荧光探针,用于环境和巯基化合物分析。本文的研究内容如下:(1)氧化钼量子点的制备。本文以市售二硫化钼粉末(MoS2)为前驱体,30%双氧水(H_2O_2)为氧化剂,采用“一锅煮”的方法合成了MoO_x QDs。与以往方法相比,本方法具有以下优点:合成速度快,在1个小时内即可完成;在室温下反应,无需外部设备辅助;合成的MoO_x QDs具有强荧光,绝对荧光量子产率为1.35%。(2)MoO_x QDs在环境水样分析中的应用。利用Eu~(3+)与MoO_x QDs和磷酸根(Pi)中氧原子结合能力的差异,建立了一种新型的“off-on”荧光传感器用于Pi的检测。Pi浓度在0.1~160mmol/L时,体系溶液荧光强度与Pi浓度有很好的线性关系,检测限为56 nmol/L(3s/k)。无需繁杂的样品前处理,该方法即可快速准确地检测环境水样中Pi。此外,利用2,4,6-三硝基甲苯(TNT)在强碱性环境中形成的Meisenheimer复合物可通过内滤效应猝灭MoO_x QDs的荧光,本文还建立了一种新型的“turn-off”荧光传感器用于检测水样中的TNT,线性范围为0.5-240.0mmol/L,检测限为0.12mmol/L。(3)MoO_x QDs在巯基化合物分析中的应用。Cu~(2+)是一种常见的荧光猝灭剂,能够通过静态猝灭机理猝灭MoO_x QDs的荧光,而活性巯基-SH与Cu~(2+)之间较强的亲和力使Cu~(2+)从与MoO_x QDs分离,从而使MoO_x QDs的荧光恢复。基于此原理,本文建立了巯基药物卡托普利(Cap)的传感平台,且实现了药物中Cap的定量分析。此外,乙酰胆碱酯酶(AchE)可催化底物硫代乙酰胆碱生成硫代胆碱(Tch)。Tch中所带有活性基团巯基可与Cu~(2+)相互作用,使得生成的MoO_x QDs-Cu~(2+)复合物解离,进而恢复MoO_x QDs的荧光。但当AchE抑制剂存在时,AchE活性被抑制,无法生成Tch,因此溶液荧光无法恢复。根据此原理,本文建立了基于MoO_x QDs-Cu~(2+)的“off-on”平台以用于AchE活性检测及其抑制剂筛选。在优化的条件下,AchE活性检测的线性范围为0.1~15.0 mU/mL,检测限为0.08 mU/mL,常见抑制剂,如扑灭津、毒死蜱等对AchE活性具有很好的抑制效果。综上,本文开发了一种快速、简便、环保的“一锅煮”方法,制备了具有强荧光的MoO_x QDs,而后将新制备的MoO_x QDs作为一种新型的荧光探针,初步研究了其在环境污染物Pi和TNT与巯基化合物分析中的应用。
[Abstract]:Molybdenum oxide nanomaterials have attracted great interest in basic science because of their excellent optical, electrical, catalytic and mechanical properties. At present, different morphologies of molybdenum oxide nanomaterials have been synthesized and great progress has been made in biochemical sensing, catalysis, lithium ion batteries and so on. However, the existing synthesis methods or operation steps of molybdenum oxide nanomaterials are tedious, time-consuming, harsh reaction conditions, or the use of organic solvents. At the same time, molybdenum oxide nanomaterials with fluorescence have not been reported, and have not been used as fluorescent probes for chemical and biological sensing. Therefore, the development of a rapid, environmentally friendly and large-scale synthesis of fluorescent molybdenum oxide nanomaterials is still a challenge. Based on this, molybdenum oxide quantum dots (MoOs x QDs) with fluorescence have been synthesized and used as a new fluorescent probe for environmental and sulfhydryl compounds analysis. The main contents of this paper are as follows: (1) preparation of molybdenum oxide quantum dots. In this paper, Moo _ x QDss were synthesized by one-pot cooking with MoS _ 2 powder (MoS _ 2) as precursor 30% H _ 2O _ 2 (H _ 2O _ 2) as oxidant. Compared with the previous methods, this method has the following advantages: the synthesis speed is fast and can be completed in one hour; the reaction at room temperature without the assistance of external equipment; the synthesized MoOx QDs have strong fluorescence, The absolute fluorescence quantum yield is 1.35. (2) the application of Moo _ x QDs in the analysis of environmental water samples. Based on the difference between EU3 and Moox QDs and oxygen atom binding ability in phosphoric acid (Pi), a new "off-on" fluorescence sensor was established for the detection of Pi. The fluorescence intensity of the system was linear with Pi concentration at concentration of 0.1 ~ 160 mmol / L. The detection limit was 56 nmol / L (3s/k). Without complicated sample pretreatment, the method can be used to detect Pii in environmental water samples quickly and accurately. In addition, the Meisenheimer complex, which was formed in a strongly alkaline environment by using 2O4O6-trinitrotoluene (TNT), can quench the fluorescence of Moox QDs by internal filtration effect. A novel "turn-off" fluorescence sensor has been developed for the determination of TNT in water samples. The linear range is 0.5-240.0 mmol / L and the detection limit is 0.12 mmol / L. (3) the application of MoOx QDs in the analysis of mercapto compounds. Cu2 is a common fluorescence quenching agent. The fluorescence of MoOx QDs can be quenched by static quenching mechanism, while the strong affinity between active mercapto -SH and Cu2 can separate Cu2 from MoOx QDs and thus restore the fluorescence of MoOx QDs. Based on this principle, the sensing platform of captopril (Cap) was established, and the quantitative analysis of Cap was realized. In addition, acetylcholinesterase (ache) can catalyze thioacetylcholine to form thiocholine (Tch). However, the activity of ache was inhibited in the presence of ache inhibitor and could not produce Tch. so the fluorescence of the solution could not be restored. Based on this principle, a "off-on" platform based on MoOx QDs-Cu2 was established for the detection of ache activity and the screening of its inhibitors. Under the optimized conditions, the linear range of the detection of ache activity was 0.1 ~ 15.0 mU / mL, and the detection limit was 0.08 MU / mL. Common inhibitors, such as extinguishing and chlorpyrifos, had a good inhibitory effect on ache activity. In this paper, a fast, simple and environmentally friendly "one pot boiling" method was developed to prepare MoOx QDswith strong fluorescence, and then the newly prepared Moo _ x QDs were used as a new fluorescent probe. Its application in the analysis of environmental pollutants Pi, TNT and sulfhydryl compounds was studied.
【学位授予单位】：东华理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O657.3

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