用于饮用水中有害阴离子检测的GaN基HEMT传感器的研究

发布时间：2018-04-12 23:00

  本文选题：AlGaN/GaN + AlInN/GaN　； 参考：《南京大学》2016年博士论文

【摘要】：水是生命之源,地球上几乎所有的动、植物都离不开它。但随着人口的增长,这种有限的水资源在日益减少；工农业技术的迅速发展,更是将各种有毒、有害的物质排入地下、江河、湖泊、水库,使地下水、地表水污染愈发加重,虽然自来水都会进行消毒处理,但消毒并不会除去重金属离子,而且会带来一些对人类健康有害的消毒副产物,如卤代乙酸类、溴酸根、氯酸根等多种阴离子,它们已被证实具有遗传毒性、致癌性或生殖发育等毒性。在此背景下,本文采用离子印迹聚合物结合GaN HEMT器件的优点构建电化学传感器,实现对磷酸根、三氯乙酸根有害阴离子的检测,本论文设计、制备的传感器对待测离子选择性强、灵敏度高、检测限低、比较稳定且可多次重复使用的特点。本文的主要研究内容和研究成果如下：1.结合磷酸根离子印迹聚合物和AlGaN/GaN HEMT器件的特性,设计了一种新型的磷酸根离子电化学传感器。AlGaN/GaN HEMT传感器的电学特性用Keithley 2600A数字源表进行表征,实验结果表明：该传感器对磷酸根离子具有高度的识别选择性,对高锰酸根、硫酸根等干扰离子不识别,这是因为离子印迹聚合物对模板离子具有专一的识别性。该传感器的灵敏度为3.191μA/mg·L-1,检测极限为1.97μg/L,对磷酸根离子表现出来高的选择性、灵敏度和稳定性,在饮用水中磷酸根离子的在线监测领域具有较大的应用潜力。2.利用AlInN/GaN异质结具有较薄势垒层,表面电荷对沟道二维电子气浓度的调控更灵敏,设计了一种超灵敏的磷酸根离子电化学传感器。通过对该传感器的I-V特性曲线测试,并将它的测试结果与AlGaN HEMT传感器进行对比,发现AlInN/GaN HEMT传感器对磷酸根离子的选择、识别性更高,抗干扰能力更强。这主要因为AlInN/GaN异质结具有比较薄的势垒层,表面电荷距离沟道2DEG比较近,有利于2DEG浓度的调控。AlInN/GaN、AlGaN/GaN HEMT传感器的灵敏度分别为60.831 μA/mg·L-1、3.191 μA/mg·L-1,检测极限分别为0.09μg/L、 1.97μg/L。这说明具有超薄势垒层的AlInN/GaN HEMT传感器比AlGaN/GaN HEMT传感器更灵敏,在离子传感器方面具有潜在的应用优势。3.改变功能单体和模板离子合成三氯乙酸离子印迹聚合物,采用新型表面印迹技术将它修饰到AlInN/GaN HEMT器件的无栅区,制备了三氯乙酸阴离子电化学传感器。通过测得的Ⅰ-Ⅴ特性曲线对传感器的性能进行研究,实验结果表明：该传感器对三氯乙酸阴离子具有比较高的选择识别,但对二氯乙酸阴离子、硫酸根等干扰离子几乎不识别,这是因为离子印迹聚合物对模板离子具有特殊的选择、识别特性。AlInN/GaN HEMT传感器的灵敏度为51.01 μA/mg·L-1,检测极限达0.01μtg／L。这说明AlInN/GaN HEMT传感器能够快速、灵敏的实现对三氯乙酸阴离子的检测,为饮用水中卤乙酸的在线监测提供了一种新的方法。
[Abstract]:Water is the source of life, almost all the animals and plants on the earth can not do without it.But with the growth of population, this limited water resource is decreasing day by day. With the rapid development of industrial and agricultural technology, all kinds of poisonous and harmful substances are being discharged into the ground, rivers, lakes, reservoirs, groundwater and surface water pollution will be aggravated.Although tap water is sanitized, disinfection does not remove heavy metal ions, but also brings some harmful disinfection by-products to human health, such as halogenated acetic acid, bromate, chlorate and other anions.They have been proved to be genotoxic, carcinogenic or reproductive toxicity.Under this background, the electrochemical sensor was constructed by using ion-imprinted polymer combined with the advantages of GaN HEMT device to detect the harmful anions of phosphate and trichloroacetate.The sensor has the advantages of high selectivity, high sensitivity, low detection limit, stability and repeated use.The main contents and results of this paper are as follows: 1.Based on the characteristics of phosphate ion imprinted polymer and AlGaN/GaN HEMT devices, a novel electrochemical sensor of phosphate ion. AlGaN / gan HEMT sensor was designed and characterized by Keithley 2600A digital source meter.The experimental results show that the sensor has high recognition selectivity for phosphate ions, and no recognition for interference ions such as high manganate and sulfate, which is due to the unique recognition of template ions by ionic imprinted polymers.The sensor has a sensitivity of 3.191 渭 A/mg L ~ (-1) and a detection limit of 1.97 渭 g 路L ~ (-1), showing high selectivity, sensitivity and stability to the phosphate ion. It has great application potential in the field of on-line monitoring of phosphate ion in drinking water.Based on the thin barrier layer of AlInN/GaN heterojunction and the sensitivity of surface charge to the control of channel two-dimensional electron gas concentration, a hypersensitive phosphate ion electrochemical sensor was designed.The I-V characteristic curve of the sensor is tested and compared with that of AlGaN HEMT sensor. It is found that the selection of phosphate ion by AlInN/GaN HEMT sensor is more recognizable and has stronger anti-interference ability.This is mainly due to the fact that the AlInN/GaN heterojunction has a thin barrier layer, and the surface charge is close to the channel 2DEG. The sensitivity of the AlInN / gan / gan HEMT sensor is 60.831 渭 A/mg L ~ (-1) ~ 3.191 渭 A/mg ~ (-1), and the detection limit is 0.09 渭 g / L and 1.97 渭 g 路L ~ (-1), respectively.This indicates that AlInN/GaN HEMT sensor with ultra-thin barrier layer is more sensitive than AlGaN/GaN HEMT sensor and has potential application advantage in ion sensor.Trichloroacetic acid ion-imprinted polymers were synthesized by changing functional monomers and template ions. The novel surface imprinting technique was applied to fabricate trichloroacetic acid anion electrochemical sensors into the gridless region of AlInN/GaN HEMT devices.The performance of the sensor was studied by the measured 鈪，

本文编号：1741792