如果重金屬積聚在體內，對人類就是一種風險。汞是一種極其危險的重金屬，而汞離子主要影響腎臟。因此，監測飲用水，自來水和果汁或我們攝入的食物中的汞濃度非常重要。有幾種技術可以檢查汞的濃度，但大多數都是基於實驗室和昂貴的，有些也不方便。由於汞相關中毒的情況越來越多，因此有必要監測汞含量。延伸閘極ISMFET傳感器可實現簡單經濟的測試，並可在極短的時間內提供特定測試材料中汞含量的可靠輸出。該傳感器實現了對目標離子具有高選擇性並對其他干擾離子具有低親和力的檢測方法。通過將離子選擇性膜與連接到FET的延伸閘極相結合，並引入具有極小間隙距離的electrical double layer(EDL)結構使我們能夠獲得高於能斯特方程式的靈敏度，並且還將檢測限提高到10-13 M比大型實驗室儀器好很多。我們還實現了10-13 M到10-5 M的感應濃度範圍。該傳感器還可用於不同水質系統的測試，如自來水，飲用水，工業廢水，藥品，食品和飲料。除了小尺寸，方便攜帶，便宜和易於製造的優點之外，這可以被創造為可靠且用戶友好的水銀傳感器

Heavy metals are a risk to humans if they get accumulated in your body. Mercury is an extremely dangerous one, if inhaled it directly targets the brain, whereas mercuric salts mainly affects the kidney. Monitoring concentration of mercury in drinking water, tap water and juices or food we intake are thus really important. There are several techniques in place in order to check the concentration of mercury but most of them are either laboratory based and expensive, some are inconvenient as well. Since there is an increasing case of mercury related poisoning it becomes necessary to monitor the mercury level. The extended gate ISMFET sensor enables easy and economical testing and provides a reliable output on the amount of mercury in that particular test material in a really short period of time. This sensor deciphers a sensing methodology which is highly selective to the target ion and offers a low affinity to other interfering ions. By combining ion-selective membrane with an extended gate device connected to a FET, and introducing the electric double layer structure with an extremely small gap distance enables us to attain sensitivity higher than the Nernst behaviour, and also improves the detection limit to 10-13 M which is much better than the benchtop instruments. We have also achieved a dynamic range from 10-13 M to 10-5 M. the sensor can also be used for real time testing in different water based systems such as tap water, drinking water, industrial waste water, medicines, food and beverages. Along with the advantages of small size, portable, less expensive and easy to fabricate this can be coined as a reliable and user friendly mercury sensor.

Chapter 1 Introduction
1.1 Motivation ………………………………..……………………………………..8

Chapter 2 Literature Review
2.1 Mercury ………………………………………………………….………………....12
2.1.1 Mercury exposure to Human and adverse effects………………….……….12
2.2 Traditional methods of ion detection ……………………………………………..16
2.3 Ion selective electrodes(ISE).……………………………………………………...18
2.3.1 Characterization of Ion Selective Electrode……......………….…………....20
2.3.2 Construction of Ion Selective Electrode………..……………………………22
2.4 Mercury Ion selective membrane ………………………………………………...25
2.5 Ion selective FET (ISFET) ………………………………………………………...27

Chapter 3 Preparation and Design of Experiments
3.1 Extended gate Hg-ISMFET Fabrication ………………………….……………...33
3.2 ISM Preparation and Immobilisation ……………………………………………34
3.3 Measurement method ……………………………………………………………..35

Chapter 4 Results and Discussion
4.1 Mercury detection test by ext. gate ISMFET ………………...………………….38
4.1.1 Investigation of sensor characteristics ………………...…………………….41
4.1.2 Mercury ion test by ext. gate Hg-ISMFET ……………..…………………..46
4.1.2.1 Investigation of lifetime of extended gate Hg-ISMFET ………...…..51
4.2 Investigation of sensor mechanism ………………………………………...……..53
4.3 Selectivity and Interfering ion test ……………………………………...………..61

Chapter 5 Applications
5.1 Blind Tests ……………………………………………………………...…………..67
5.1.1 Mercury ion blind test by extended gate Hg-ISMFET in fruit juice sample …………………………………….…………………...…………………….68
5.1.2 Mercury ion blind test by extended gate Hg-ISMFET in Chinese medicine samples……….……………………………….…………………………..70
5.1.3 Mercury ion blind test by extended gate Hg-ISMFET in industrial waste water sample ……………………………...………………………………….74

Chapter 6 Conclusion………………………………………………..…………………78

References …………………………………………………………………………………..

1 Tchounwou, P. B., Yedjou, C. G., Patlolla, A. K. & Sutton, D. J. Heavy Metals Toxicity and the Environment. EXS 101, 133-164, doi:10.1007/978-3-7643-8340-4_6 (2012).
2 Duffus, J. H. "Heavy metals"-A meaningless term? (IUPAC Technical Report). Pure and Applied Chemistry 74, 793-807 ( 2002).
3 Jaishankar, M., Tseten, T., Anbalagan, N., Mathew, B. B. & Beeregowda, K. N. Toxicity, mechanism and health effects of some heavy metals. Interdisciplinary Toxicology 7, 60-72, doi:10.2478/intox-2014-0009 (2014).
4 Organization, W. H. The public health impact of chemicals: knowns and unknowns. World Health Organization WHO/FWC/PHE/EPE/16.01 (2016).
5 Bjorklund, G., Bengtsson, U., Chirumbolo, S. & Kern, J. Concerns about environmental mercury toxicity: do we forget something else? , Vol. 152 (2017).
6 Prüss-Ustün, A., Vickers, C., Haefliger, P. & Bertollini, R. Knowns and unknowns on burden of disease due to chemicals: a systematic review. Environmental Health 10, 9, doi:10.1186/1476-069X-10-9 (2011).
7 Shukla, G. S. & Singhal, R. L. The present status of biological effects of toxic metals in the environment: lead, cadmium, and manganese. Canadian Journal of Physiology and Pharmacology 62, 1015-1031, doi:10.1139/y84-171 (1984).
8 Gibb H, O. L. K. Mercury exposure and health impacts among individuals in the artisanal and small-scale gold mining community: a comprehensive review. Environ Health Perspect 122, 667–672 (2014).
9 Siqi Zhu, B. C., Man He,Tong Huang,Bin Hu. Speciation of mercury in water and fish samples by HPLC-ICP-MS after magnetic solid phase extraction. Talanta 171, 213-219 (2017).
10 A Bernhoft, R. Mercury Toxicity and Treatment: A Review of the Literature. Vol. 2012 (2012).
11 Fish and Shellfish program newsletter. United States Environment Protection Agency.
12 Pyle, S. M. et al. Comparison of AAS, ICP-AES, PSA, and XRF in Determining Lead and Cadmium in Soil. Environmental Science & Technology 30, 204-213, doi:10.1021/es9502482 (1996).
13 Allibone, J., Fatemian, E. & J Walker, P. Determination of mercury in potable water by ICP-MS using gold as a stabilising agent. Journal of Analytical Atomic Spectrometry 14, 235-239, doi:10.1039/A806193I (1999).
14 Masatoshi Morita, J. Y., John S Edmonds. The determination of Mercury species in environmental and biological samples. International Union of Pure and Applied Chemistry 70 1585-1615 (1998).
15 Asadnia, M. et al. Mercury(II) selective sensors based on AlGaN/GaN transistors. Vol. 943 (2016).
16 Lee, C.-S., Kim, S. & Kim, M. Ion-Sensitive Field-Effect Transistor for Biological Sensing. Sensors 9, 7111–7131 (2009).
17 Ambacher, O. et al. Two-dimensional electron gases induced by spontaneous and piezoelectric polarization charges in N- and Ga-face AlGaN/GaN heterostructures. Journal of Applied Physics 85, 3222-3233, doi:10.1063/1.369664 (1999).
18 D, H. The Diseases of Occupations. 4 edn, 314–328 (1969).
19 Sarangadharan, I. et al. High sensitivity cardiac troponin I detection in physiological environment using AlGaN/GaN High Electron Mobility Transistor (HEMT) Biosensors. Vol. 100 (2017).
20 Chu, C.-H. et al. Beyond the Debye length in high ionic strength solution: direct protein detection with field-effect transistors (FETs) in human serum. Scientific Reports 7, 5256, doi:10.1038/s41598-017-05426-6 (2017).
21 Sarangadharan, I. et al. Single Drop Whole Blood Diagnostics: Portable Biomedical Sensor for Cardiac Troponin I Detection. Vol. 90 (2018).
22 Chen, Y.-W. et al. Highly Sensitive and Rapid MicroRNA Detection for Cardiovascular Diseases with Electrical Double Layer (EDL) Gated AlGaN/GaN High Electron Mobility Transistors. Vol. 262 (2018).
23 Huan-Shu-Tu-Tzu. (Environmental Protection Administration, Taiwan, 2009).
24 Rice, K. M., Walker, E. M., Wu, M., Gillette, C. & Blough, E. R. Environmental Mercury and Its Toxic Effects. Journal of Preventive Medicine and Public Health 47, 74-83, doi:10.3961/jpmph.2014.47.2.74 (2014).
25 Vol. Environmental Health Criteria 1 (World Health Organization, Geneva, 1976).
26 Bakir, F. et al. Methylmercury poisoning in Iraq. Science (New York, N.Y.) 181, 230-241 (1973).
27 Bennett, B. Anatomy of the Amazon Gold Rush. The Latin American Anthropology Review 3, 25-26, doi:10.1525/jlca.1991.3.1.25.2 (1991).
28 Pfeiffer, W. C. & de Lacerda, L. D. Mercury inputs into the Amazon Region, Brazil. Environmental Technology Letters 9, 325-330, doi:10.1080/09593338809384573 (1988).
29 EPA., U. S. Mercury Report to Congress Office of Air Quality and Standards
U.S. Environmental Protection Agency (1997).
30 EPA., U. S. Water Quality Criterion for the Protection of Human Health: Methyl Mercury. (2001).
31 Registry, A. f. T. S. a. D. Toxicological Profile for Mercury. :, . (1999).
32 Cernichiari, E. et al. Monitoring methylmercury during pregnancy: maternal hair predicts fetal brain exposure. Neurotoxicology 16, 705-710 (1995).
33 Kerper, L. E., Ballatori, N. & Clarkson, T. W. Methylmercury transport across the blood-brain barrier by an amino acid carrier. The American journal of physiology 262, R761-765, doi:10.1152/ajpregu.1992.262.5.R761 (1992).
34 Magos, L. et al. The comparative toxicology of ethyl- and methylmercury. Archives of toxicology 57, 260-267 (1985).
35 Davis, L. E. et al. Methylmercury poisoning: long-term clinical, radiological, toxicological, and pathological studies of an affected family. Annals of neurology 35, 680-688, doi:10.1002/ana.410350608 (1994).
36 Slaets, S., Adams, F., Rodriguez Pereiro, I. & Lobinski, R. Optimization of the coupling of multicapillary GC with ICP-MS for mercury speciation analysis in biological materials. Journal of Analytical Atomic Spectrometry 14, 851-857, doi:10.1039/A809296F (1999).
37 Bushee, D. S. Speciation of Mercury Using Liquid Chromatography with Detection by Inductively Coupled Plasma Mass Spectrometry Center for Analytical Chemistry,National Bureau of Standards
Vol. 113 (Analyst, 1988).
38 ICP-OES and ICP-MS detection limit guidance. (Nanoscience).
39 Wojciech Wroblewski Warsaw University of Technology, D. o. A. C., Noakowskiego 300-664 (Warsaw, Poland).
40 Mahajan, R. K., Sood, P., Pal Mahajan, M. & Marwaha, A. Mercury(II) ion-selective electrodes based on heterocyclic systems. Annali di chimica 97, 959-970 (2007).
41 Bakker, E., Bühlmann, P. & Pretsch, E. Carrier-Based Ion-Selective Electrodes and Bulk Optodes. 1. General Characteristics. Chemical Reviews 97, 3083-3132, doi:10.1021/cr940394a (1997).
42 Wang, J. Analytical Electrochemistry. Vol. Frontmatter (John Wiley and Sons, 2006).
43 Buhlmann, P., Pretsch, E. & Bakker, E. Carrier-Based Ion-Selective Electrodes and Bulk Optodes. 2. Ionophores for Potentiometric and Optical Sensors. Chem Rev 98, 1593-1688 (1998).
44 Kaushal, S., Badru, R., Kumar, S., Mittal, S. K. & Singh, P. Fabrication of a mercury(ii) ion selective electrode based on poly-o-toluidine-zirconium phosphoborate. RSC Advances 6, 3150-3158, doi:10.1039/C5RA23284H (2016).
45 Lu, J., Tong, X. & He, X. A mercury ion-selective electrode based on a calixarene derivative containing the thiazole azo group. Journal of Electroanalytical Chemistry 540, 111-117, doi:https://doi.org/10.1016/S0022-0728(02)01298-6 (2003).
46 Bose-O'Reilly, S., McCarty, K. M., Steckling, N. & Lettmeier, B. Mercury exposure and children's health. Current problems in pediatric and adolescent health care 40, 186-215, doi:10.1016/j.cppeds.2010.07.002 (2010).
47 Belyustin, A. The centenary of glass electrode: From Max Cremer to F. G. K. Baucke. Vol. 15 (2010).
48 Marczewska, B. & Marczewski, K. First Glass Electrode and its Creators F. Haber and Z. Klemensiewicz – On 100th Anniversary. Vol. 224 (2010).
49 Yin, T., Pan, D. & Qin, W. All-Solid-State Polymeric Membrane Ion-Selective Miniaturized Electrodes Based on a Nanoporous Gold Film as Solid Contact. Analytical Chemistry 86, 11038-11044, doi:10.1021/ac5029209 (2014).
50 Coetzee, C. J. & Freiser, H. Liquid-liquid membrane electrodes based on ion-association extraction systems. Analytical Chemistry 41, 1128-1130, doi:10.1021/ac60277a017 (1969).
51 Frant, M. S. Historical perspective. History of the early commercialization of ion-selective electrodes. Analyst 119, 2293-2301, doi:10.1039/AN9941902293 (1994).
52 Ikeda, A. & Shinkai, S. Novel Cavity Design Using Calix[n]arene Skeletons:  Toward Molecular Recognition and Metal Binding. Chemical Reviews 97, 1713-1734, doi:10.1021/cr960385x (1997).
53 Lai, M.-T. & Shih, J.-S. Mercury(II) and silver(I) ion-selective electrodes based on dithia crown ethers. Analyst 111, 891-895, doi:10.1039/AN9861100891 (1986).
54 Wang, H.-T. et al. Fast electrical detection of Hg (II) ions with AlGaN∕ GaN high electron mobility transistors. Vol. 91 (2007).
55 T. Wang, H. et al. Selective detection of Hg (II) ions from Cu(II) and Pb(II) using AlGaN/GaN high electron mobility transistors. Vol. 10 (2007).
56 Asadnia, M. et al. Mercury(II) selective sensors based on AlGaN/GaN transistors. Analytica chimica acta 943, 1-7, doi:10.1016/j.aca.2016.08.045 (2016).
57 Gupta, V., Chandra, S. & Agarwal, S. Mercury selective electrochemical sensor based on a double armed crown ether as ionophore. Vol. 42 (2003).
58 Myers, M. et al. Nitrate ion detection using AlGaN/GaN heterostructure-based devices without reference electrode. (2013).
59 Bergveld, P. Development, operation, and application of the ion-sensitive field-effect transistor as a tool for electrophysiology. IEEE transactions on bio-medical engineering 19, 342-351, doi:10.1109/tbme.1972.324137 (1972).
60 Duroux, P. et al. The ion sensitive field effect transistor (ISFET) pH electrode: a new sensor for long term ambulatory pH monitoring. Gut 32, 240-245 (1991).
61 Bergveld, P. Development of an ion-sensitive solid-state device for neurophysiological measurements. IEEE transactions on bio-medical engineering 17, 70-71 (1970).
62 Bousse, L. & Bergveld, P. The Role of Buried OH Sites in the Response Mechanism of Inorganic-Gate pH-Sensitive ISFETs. Vol. 6 (1984).
63 van den Berg, A., Bergveld, P., Reinhoudt, D. N. & Sudhölter, E. J. Sensitivity control of ISFETs by chemical surface modification. Sensors and Actuators 8, 129-148, doi:https://doi.org/10.1016/0250-6874(85)87010-4 (1985).
64 E. Yates, D., Levine, S. & W. Healy, T. Site-Binding Model of the Electrical Double Layer at the Oxide/Water Interface. Vol. 70 (1974).
65 Thi Ngoc Mai, P. & Phan, H. Fabrication of Solid Contact Ion Selective Electrode for Mercury (II) Using Conductive Polymer Membrane. Vol. 56 (2015).
66 Yao, P.-C., Chiang, J.-L. & Lee, M.-C. Application of sol–gel TiO2 film for an extended-gate H+ ion-sensitive field-effect transistor. Solid State Sciences 28, 47-54, doi:https://doi.org/10.1016/j.solidstatesciences.2013.12.011 (2014).
67 Spijkman, M. et al. Beyond the Nernst-limit with dual-gate ZnO ion-sensitive field-effect transistors. Vol. 98 (2011).
68 Tohda, K., Dragoe, D., Shibata, M. & Umezawa, Y. Studies on the matched potential method for determining the selectivity coefficients of ion-selective electrodes based on neutral ionophores: experimental and theoretical verification. Analytical sciences : the international journal of the Japan Society for Analytical Chemistry 17, 733-743 (2001).
69 Zhou, G. et al. Ultrasensitive Mercury Ion Detection Using DNA-Functionalized Molybdenum Disulfide Nanosheet/Gold Nanoparticle Hybrid Field-Effect Transistor Device. ACS Sensors 1, 295-302, doi:10.1021/acssensors.5b00241 (2016).
70 Li, P., Zhang, D., Jiang, C., Zong, X. & Cao, Y. Ultra-sensitive suspended atomically thin-layered black phosphorus mercury sensors. Biosensors & bioelectronics 98, 68-75, doi:10.1016/j.bios.2017.06.027 (2017).