汞离子的比率型电化学传感和荧光增强分析

发布时间：2018-01-21 13:15

本文关键词： 汞离子电化学传感检测和除去荧光增强探针环境和生物体分析　出处：《华东师范大学》2017年硕士论文　论文类型：学位论文

【摘要】：近年来,随着工业不断发展,重金属离子污染也日趋严重,其中,汞离子(Hg~(2+))作为一种对环境及生物体有毒的重金属污染离子,不仅对人类的消化系统、神经系统、肝脏以及其他器官有严重损伤,而且对其他物种同样损伤严重。所以,美国环境保护署(EPA)和世界健康组织(WHO)规定,在饮用水中能检测到的Hg~(2+)浓度必须小于2ppb。除此之外,汞污染也十分严重,为了处理汞污染,人们不仅需要开发新材料检测更低浓度的Hg~(2+),更重要的是还能将其从溶液中快速移除。因此,发展一种高灵敏的可用于环境及生物体中Hg~(2+)的检测并移除的新方法具有非常重要的意义。本文主要采用电化学传感和荧光增强两种分析方法,设计并开发具有高性能的Hg~(2+)探针,实现了对Hg~(2+)高灵敏高准确度的检测,具体内容如下:(一)我们设计并制备了一种超灵敏比率型电化学传感器,可准确检测和除去水中Hg~(2+),并成功实现了环境水样和生物体中Hg~(2+)含量的检测。首先,我们设计并合成了能够与Hg~(2+)特异性结合的有机功能分子苯基硫脲(phenyl thiourea,PT),并将识别分子PT修饰到电极表面制备了性能稳定的汞离子传感器。该传感器具有良好的选择性,不受其他金属离子和氨基酸的影响。其次,采用了电沉积金和金纳米球放大信号的方法,将Hg~(2+)的测定灵敏度显著提高了 5.3倍。与此同时,将内参比HS-DNA-MB(MB =Methylene Blue)分子共组装于三维纳米金电极表面,构筑了检测Hg~(2+)的比率型电化学探针。该方法在1nM～1.3 μM范围内呈现良好线性关系,检测限低至0.12 nM(0.024 ppb),完全可以满足WHO和EPA的检测需求。最后,我们将该传感成功应用于实际水样和斑马鱼中Hg~(2+)的检测。检测结果与传统电感耦合等离子体质谱法(ICP-MS)一致,证明我们的检测方法更简单准确,成本更低。更重要的是,该比率型电化学探针可用于痕量汞的高效率移除,移除效率高达99%。(二)我们开发了一种基于荧光增强原理来检测Hg~(2+)的新型荧光探针。首先,制备了多种金属纳米材料,结果表明,不同长径比的金纳米棒与传统的球形纳米颗粒相比具有良好的荧光增强效果。然后通过静电作用实现了金纳米棒与能够特异性识别Hg~(2+)的荧光染料相结合,通过多聚物层层自组装优化了荧光增强效果最佳的距离,制备了无机-有机的Hg~(2+)测定体系,实现了 Hg~(2+)的检测,该方法有望用于细胞中Hg~(2+)的检测。
[Abstract]:In recent years, with the continuous development of industry, the pollution of heavy metal ions is becoming more and more serious. Not only are there serious damage to the human digestive system, nervous system, liver and other organs, but also to other species. The Environmental Protection Agency (EPA) and the World Health Organization (WHO) require that the concentration of Hg~(2 detectable in drinking water must be less than 2 ppb. in addition, mercury pollution is very serious. In order to deal with mercury pollution, it is necessary not only to develop new materials to detect lower concentrations of Hg~(2, but also to remove it quickly from solution. It is of great significance to develop a highly sensitive method for the detection and removal of Hg~(2 in the environment and organisms. In this paper, two analytical methods, electrochemical sensing and fluorescence enhancement, are used. The Hg~(2 probe with high performance is designed and developed to detect Hg~(2 with high sensitivity and accuracy. The main contents are as follows: (1) We have designed and fabricated an ultra-sensitive ratio electrochemical sensor, which can accurately detect and remove Hg~(2 in water. And has successfully realized the environmental water sample and the organism Hg~(2 content detection. First. We have designed and synthesized phenyl thioureaPTs, an organic functional molecule that can specifically bind to Hg~(2. The recognition molecule PT was modified to the electrode surface to prepare a stable mercury ion sensor. The sensor has good selectivity and is not affected by other metal ions and amino acids. Secondly. The sensitivity of Hg~(2 was increased by 5.3 times by using electrodeposition of gold and gold nanospheres to amplify the signal. The internal reference HS-DNA-MB(MB methylene Blue molecules were co-assembled on the surface of three-dimensional gold nanocrystalline electrode. A ratio electrochemical probe for the detection of Hg~(2 was constructed, and the linear range of the method was 1. 3 渭 m. The detection limit is as low as 0. 12 nM(0.024 PbBX, which can completely meet the detection requirements of WHO and EPA. Finally. We have successfully applied the sensor to the detection of Hg~(2 in real water samples and zebrafish. The results are consistent with the conventional ICP-MS method. It is proved that our detection method is simpler, more accurate, cheaper and more important, the ratio electrochemical probe can be used for the efficient removal of trace mercury. We have developed a new fluorescent probe based on fluorescence enhancement principle to detect Hg~(2. First, we have prepared a variety of metal nanomaterials, and the results show that. The gold nanorods with different aspect ratios have good fluorescence enhancement effect compared with the traditional spherical nanoparticles. Then the gold nanorods and Hg~(2 can be specifically recognized by electrostatic action. Of fluorescent dyes. The best distance of fluorescence enhancement was optimized by layer by layer self-assembly of polymer. Inorganic-organic Hg~(2) system was prepared and the detection of Hg~(2) was realized. This method is expected to be used for the detection of Hg~(2 in cells.
【学位授予单位】：华东师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O657

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