基于纳米材料修饰电极的酚类污染物电化学传感器研究

发布时间：2019-06-08 06:54

【摘要】：随着经济的发展,酚类物质被大量应用于工业领域,对土壤和水环境造成了污染,且其在环境中很难降解,不断累积的酚类污染物会通过食物链进入到人体中。由于酚类物质的较大毒性,即使在浓度很低时都会造成人体机能紊乱甚至致癌,因此,发展一种对环境中的酚类污染物进行快速、准确测定的方法,有着十分重要的现实意义。目前检测酚类物质的方法较多,电化学方法具有成本低、快速方便、灵敏度和准确度高、检测的浓度范围宽等优点,广泛应用于酚类物质的检测。在电化学分析中,可通过将电极表面附着上一些功能性的物质制备化学修饰电极,来增加电极的电流响应、提高检测的灵敏度。本文通过构建了四种纳米材料修饰电极,对不同种的酚类物质进行了测定。主要研究内容如下:1.基于离子液体功能化类水滑石的双酚A电化学传感器研究采用共沉淀法合成了氨基功能化离子液体(1-胺丙基-3-甲基咪唑四氟硼酸盐)修饰的锌铝类水滑石(ILs-LDH),通过滴涂法将ILs-LDH修饰在玻碳电极表面,制得ILs-LDH/GCE修饰电极,并将其用于双酚A的测定。实验结果表明,该修饰电极可加快双酚A的电化学氧化进程,使其氧化峰电流明显增加,氧化过电位明显降低。在最优实验条件下,采用DPV进行测定,双酚A在0.02~3μM的浓度范围内与其氧化峰电流值呈线性关系,其检出限为4.6 nM(S/N=3)。此外,将其应用于实际水样中的双酚A检测,回收率在94.9%到102.0%之间。2.基于超薄类水滑石纳米片的双酚A电化学传感器研究超薄Ni_2Al类水滑石纳米片(ELDH)在水溶介质中用L-天冬酰胺剥离,剥离的纳米片直径约为200 nm,厚度小于3 nm。制备超薄类水滑石纳米片修饰电极对双酚A进行检测,结果显示修饰电极呈现优良的电化学性能,双酚A具有较低的氧化电位(0.489 V)。差分脉冲伏安法对双酚A检测呈现较宽的线性检测范围(0.02~1.51μM)和较低的检出限(6.8 nM)。此外,将其应用于实际牛奶样品的检测,结果满意。3.基于离子液体结构化的氮化碳纳米片电化学传感器用于2,4-二氯酚的检测用正溴丁烷与质子化已剥离的氮化碳反应,得到离子液体结构化的氮化碳纳米片。将其修饰到电极表面,制备IL-eC3N4/GCE,结果表明该修饰电极对2,4-DCP的电化学氧化有较强的催化活性,2,4-二氯酚的氧化峰电位明显负移。电流-时间曲线显示2,4-DCP的浓度在0.02~160μM之间,峰电流与浓度成正比且检出限为6.67 nM。此外,将其应用于湖水和矿物水中邻苯二酚的检测,加标回收率在97%~106%之间。4.基于碳量子点-银复合物的邻苯二酚电化学传感器的研究一步水热法合成了氮硫掺杂的碳量子点,然后用碳量子点原位还原硝酸银制备了碳量子点-银纳米复合物(N-S-CQDs-Ag),将N-S-CQDs-Ag修饰到玻碳电极表面构建检测邻苯二酚的电化学传感器。分析结果表明,该传感器明显降低了邻苯二酚的氧化还原峰电位差(ΔEp),线性检测范围为0.2~180μM,检出限为0.013μM,实现了对邻苯二酚的高灵敏和高效分析。此外,将其应用于湖水和自来水中邻苯二酚的检测,加标回收率在97%~107%之间。
[Abstract]:With the development of economy, the phenolic substances are widely used in the industrial field, and the soil and the water environment are polluted, and the phenolic contaminants are difficult to degrade in the environment, and the continuously accumulated phenolic contaminants can enter into the human body through the food chain. Because of the great toxicity of the phenolic substances, even when the concentration is low, the human body function disorder is even carcinogenic, therefore, the method for rapidly and accurately measuring the phenolic contaminants in the environment is of great practical significance. The method for detecting the phenolic substance is more, the electrochemical method has the advantages of low cost, high speed, high sensitivity and accuracy, wide detection concentration range and the like, and is widely applied to the detection of the phenolic substances. In the electrochemical analysis, a chemical modification electrode can be prepared by attaching some of the functional materials to the surface of the electrode to increase the current response of the electrode and improve the detection sensitivity. In this paper, four kinds of nano-material modified electrodes were constructed, and different kinds of phenolic compounds were measured. The main contents of the study are as follows:1. The zinc-aluminum hydrotalcite (ILs-LDH) modified by amino-functional ionic liquid (1-aminopropyl-3-methyl-4-fluoroborate) was synthesized by co-precipitation method based on the study of the ionic liquid-functionalized hydrotalcite-based bisphenol A electrochemical sensor. The ILs-LDH was modified on the surface of the glassy carbon electrode by a drop coating method, and the ILs-LDH/ GCE modified electrode was prepared and used in the determination of bisphenol A. The experimental results show that the modified electrode can accelerate the electrochemical oxidation process of bisphenol A, and the oxidation peak current of the modified electrode is obviously increased, and the oxidation potential is obviously reduced. Under the optimum experimental conditions, DPV was used to determine the concentration of bisphenol A in the concentration range of 0.02 to 3. m u.M, and the detection limit was 4.6 nM (S/ N = 3). In addition, it is applied to the detection of bisphenol A in the real water sample, and the recovery rate is between 94.9% and 102.0%. In this paper, an ultra-thin Ni _ 2Al hydrotalcite-like nano-sheet (ELDH) is separated by L-triammine in a water-soluble medium based on an ultra-thin hydrotalcite-like nano-sheet, and the peeled nano-sheet has a diameter of about 200 nm and a thickness of less than 3 nm. The result showed that the modified electrode exhibited excellent electrochemical performance and bisphenol A had a lower oxidation potential (0.489 V). The differential pulse voltammetry showed a wide linear detection range (0.02-1.51. mu.M) and a lower detection limit (6.8 nM) for bisphenol A detection. In addition, it is applied to the detection of real milk samples, and the results are satisfactory. The ion-liquid-structured carbon nitride nanosheet electrochemical sensor is used for the detection of 2,4-dichlorophenol, and the n-bromobutane is reacted with the deprotonated carbon nitride to obtain the ionic liquid-structured carbon nitride nanosheet. The results show that the modified electrode has strong catalytic activity to the electrochemical oxidation of 2,4-DCP, and the oxidation peak potential of 2,4-dichlorophenol is obviously negative. The current-time curve shows that the concentration of 2,4-DCP is between 0.02 and 160. m u.M, the peak current is proportional to the concentration and the detection limit is 6.67 nM. In addition, the method is applied to the detection of the catechol in the lake water and the mineral water, and the recovery rate of the spike is between 97% and 106%. A carbon quantum dot-silver nano-composite (N-S-CQDs-Ag) is prepared by a step-by-step hydrothermal method of a pyrocatechol electrochemical sensor based on a carbon quantum dot-silver complex, And the N-S-CQDs-Ag is modified to the surface of the glassy carbon electrode to construct an electrochemical sensor for detecting the catechol. The results of the analysis show that the oxidation-reduction peak potential difference (OEp) of the pyrocatechol is obviously reduced, the linear detection range is 0.2-180. m u.M, the detection limit is 0.013. m u.M, and the high-sensitivity and high-efficiency analysis of the catechol is realized. In addition, the method is applied to the detection of the catechol in the lake water and the tap water, and the recovery rate of the spike is between 97% and 107%.
【学位授予单位】：青岛科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O657.1

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