本實驗利用過渡金屬氧化物二氧化釕應用於生物電化學檢測之研究中，為了擴大及改善二氧化釕之表面積不足，將其沉積於奈米碳管之表面上作為結合，以改善其表面積較低之特性，進而提升其檢測能力，奈米碳管之結構穩定於生物感測中造成靈敏度不足，常需要進一步的化學處理，但此實驗中因二氧化釕與奈米碳管結合即可達到尿酸感測的功用，不需其他步驟處理奈米碳管之化性。此兩者材料之結合的優點為：(1) 因二氧化釕與奈米碳管之晶格常數接近，能得到穩定的結合，(2) 得到較大的有效表面積，提升尿酸檢測靈敏度。使用循環伏安法的掃描模式來檢測尿酸之濃度，隨著掃描速率的增加，我們發現氧化峰電流值以線性的方式增大，這表示擁有電活性的尿酸物質是以化學吸附的方式在此電極上產生氧化峰之電流。另外，在人體血漿中含有其他電活性物質也會造成電化學量測中的誤差與降低解析度，因此在量測尿酸濃度時，同時也加入其他干擾物質，如：維他命C與多巴胺。於有干擾物質的環境下，此電極於循環伏安法之掃描下仍可以得到隨著尿酸濃度增加而線性增加的氧化峰值，並且能得到好的靈敏度與低的偵測極限，此靈敏度為72 nM及偵測極限為4.36 uA/uM。另外為了克服背景電流值的問題，也使用差式脈波伏安法作為掃描方式，可得到更低的偵測極限為55 nM。在本論文，我們亦利用可撓的石墨烯作為導電基板與奈米碳管及二氧化釕做結合並應用於生物電化學檢測中，因石墨烯的可撓性更提高了此元件可應用之範圍與領域，經循環伏安法之掃描下此電極可得氧化峰值與尿酸濃度的關係是為線性，其靈敏度為1.80 uA/uM及偵測極限為30 nM。另外，本論文亦將二氧化釕沉積於圖形化之奈米碳管上並以石墨烯為導電基板，應用於超級電容器的使用上，由於奈米碳管之高數密度，會限制電解液與電極之接觸面積，因而藉由黃光微影之技術，將奈米碳管圖形化，使電解液容易與電極接觸，再與擁有優異偽電容特性之二氧化釕結合，能得到不錯的有效電容值，由實驗結果顯示電容值為128.40 F/g。

Transitional metal oxide, RuO2 nanostructures were used in uric acid (UA) biosensor electrochemical analysis. The RuO2 nanostructures were combined with carbon nanotubes (CNTs) to enhance the lower effective specific surface area and improve the detection sensitivity. The CNT structural stability resulted in insufficient sensitivity, making chemical treatments necessary. The CNTs combined with RuO2 can achieve the UA detection goal without extra chemical treatments. The combination of CNTs and RuO2 nanostructures has the following advantages: Their similar lattice constants obtain structural stability. The relatively larger specific surface area offers greater sensitivity. The current densities of the redox peaks linearly increase with the scan rate under cyclic voltammetry, meaning that the UA electroactive molecules are an adsorption-controlled process on the electrode (RuO2/CNTs). Because there are other biomolecules in human serum that may cause UA detection derivation and low sensitivity, ascorbic acid (AA) and dopamine (DA) were added into the UA solution during the measurement. In the presence of AA and DA the RuO2/CNTs electrode still obtained a linear relationship between the oxidation peak current density and UA concentration with the greatest sensitivity at 4.36 uA/uM and the low detection limit of 72 nM. The RuO2/CNTs electrode was produced under differential pulse voltammetry (DPV) with the lower detection limit of 55 nM to eliminate background current. Flexible graphene is a conductive substrate for the growth of the RuO2/CNTs composite and applied in UA biosensors. Because the flexibility and chemical stability of graphene is suitable in UA biosensor application and broadens the applicable fields, the sensitivity and the detection limit of RuO2/CNTs/graphene were 1.80 uA/uM and 30 nM, respectively. RuO2 nanostructures were coated onto patterned CNTs in supercapacitor applications. Owing to the high number density of CNTs, the electrolyte will not be able to permeate into them, thereby reducing the effective specific surface area and the supercapacitor performance. With the aid of photolithography, CNTs were patterned and became CNT bundles. The excellent capacitance of 151.83 F/g was obtained from RuO2 nanostructures with outstanding pseudo-capacitive performance coated onto the CNT bundles.

[1] W. Boyes, Instrumentation Reference Book, Boston: Butterworth-Heinemann, 2010.
[2] A. K. Bewoor and V. A. Kulkarni, Metrology and Measurement, New Delhi: Tata McGraw-Hill Education, 2009.
[3] Y. Jia, K. Sun, F. J. Agosto, and M. T. Quĩones, "Design and characterization of a passive wireless strain sensor," Meas. Sci. Technol., vol. 17, pp. 2869-2876, 2006.
[4] J. F. Tressler, S. Alkoy, and R. E. Newnham, "Piezoelectric sensors and sensor materials," J. Electroceram., vol. 2, pp. 257-272, 1998.
[5] F. A. A. Matias, M. M. D. C. Vila, and M. Tubino, "A simple device for quantitative colorimetric diffuse reflectance measurements," Sens. Actuators B, vol. 88, pp. 60-66, 2003.
[6] S. V. Litvinenko, A. V. Kozinetz, and V. A. Skryshevsky, "Concept of photovoltaic transducer on a base of modified p-n junction solar cell," Sens. Actuators, A, vol. 224, pp. 30-35, 2015.
[7] N. A. Hall and F. L. Degertekin, "Integrated optical interferometric detection method for micromachined capacitive acoustic transducers," Appl. Phys. Lett., vol. 80, pp. 3859-3861, 2002.
[8] M. T. Abuelma'atti, "Harmonic and intermodulation distortion in carbon microphones," Appl. Acoust., vol. 31, pp. 233-243, 1990.
[9] L. C. Clark Jr and C. Lyons, "Electrode systems for continuous monitoring in cardiovascular surgery," Ann. N.Y. Acad. Sci., vol. 102, pp. 29-45, 1962.
[10] A. P. F. Turner, "Biosensors: Sense and sensibility," Chem. Soc. Rev., vol. 42, pp. 3184-3196, 2013.
[11] K. Ramanathan and B. Danielsson, "Principles and applications of thermal biosensors," Biosens. Bioelectron., vol. 16, pp. 417-423, 2001.
[12] Z. Qie, B. Ning, M. Liu, J. Bai, Y. Peng, N. Song, Z. Lv, Y. Wang, S. Sun, X. Su, Y. Zhang, and Z. Gao, "Fast detection of atrazine in corn using thermometric biosensors," Analyst, vol. 138, pp. 5151-5156, 2013.
[13] X. Fan, I. M. White, S. I. Shopova, H. Zhu, J. D. Suter, and Y. Sun, "Sensitive optical biosensors for unlabeled targets: A review," Anal. Chim. Acta, vol. 620, pp. 8-26, 2008.
[14] R. J. Green, J. Davies, M. C. Davies, C. J. Roberts, and S. J. B. Tendler, "Surface plasmon resonance for real time in situ analysis of protein adsorption to polymer surfaces," Biomaterials, vol. 18, pp. 405-413, 1997.
[15] J. H. Lee, K. H. Yoon, K. S. Hwang, J. Park, S. Ahn, and T. S. Kim, "Label free novel electrical detection using micromachined PZT monolithic thin film cantilever for the detection of C-reactive protein," Biosens. Bioelectron., vol. 20, pp. 269-275, 2004.
[16] G. Y. Kang, G. Y. Han, J. Y. Kang, I.-H. Cho, H.-H. Park, S.-H. Paek, and T. S. Kim, "Label-free protein assay with site-directly immobilized antibody using self-actuating PZT cantilever," Sens. Actuators B, vol. 117, pp. 332-338, 2006.
[17] K. Ikebukuro, C. Kiyohara, and K. Sode, "Novel electrochemical sensor system for protein using the aptamers in sandwich manner," Biosens. Bioelectron., vol. 20, pp. 2168-2172, 2005.
[18] M. Mir, M. Vreeke, and I. Katakis, "Different strategies to develop an electrochemical thrombin aptasensor," Electrochem. Commun., vol. 8, pp. 505-511, 2006.
[19] Y. Wang, H. Xu, J. Zhang, and G. Li, "Electrochemical Sensors for Clinic Analysis," Sensors, vol. 8, p. 2043, 2008.
[20] E. S. Gil and G. R. de Melo, "Electrochemical biosensors in pharmaceutical analysis," Braz. J. Pharm. Sci., vol. 46, pp. 375-391, 2010.
[21] G. Hanrahan, D. G. Patil, and J. Wang, "Electrochemical sensors for environmental monitoring: Design, development and applications," J. Environ. Monit., vol. 6, pp. 657-664, 2004.
[22] I. E. Tothill, "Biosensors developments and potential applications in the agricultural diagnosis sector," Comput. Electron. Agric., vol. 30, pp. 205-218, 2001.
[23] U. E. Spichiger-Keller, Chemical sensors and biosensors for eedical and biological applications, Federal Republic of Germany: Wiley-VCH, 2008.
[24] F. Zhang, J. Tang, Z. Wang, and L.-C. Qin, "Graphene–carbon nanotube composite aerogel for selective detection of uric acid," Chem. Phys. Lett., vol. 590, pp. 121-125, 2013.
[25] D. Lakshmi, M. J. Whitcombe, F. Davis, P. S. Sharma, and B. B. Prasad, "Electrochemical Detection of Uric Acid in Mixed and Clinical Samples: A Review," Electroanalysis, vol. 23, pp. 305-320, 2011.
[26] X. Dai, X. Fang, C. Zhang, R. Xu, and B. Xu, "Determination of serum uric acid using high-performance liquid chromatography (HPLC)/isotope dilution mass spectrometry (ID-MS) as a candidate reference method," J. Chromatogr. B, vol. 857, pp. 287-295, 2007.
[27] J. Perelló, P. Sanchis, and F. Grases, "Determination of uric acid in urine, saliva and calcium oxalate renal calculi by high-performance liquid chromatography/mass spectrometry," J. Chromatogr. B, vol. 824, pp. 175-180, 2005.
[28] H. C. Hong and H. J. Huang, "Flow injection analysis of uric acid with a uricase- and horseradish peroxidase-coupled Sepharose column based luminol chemiluminescence system," Anal. Chim. Acta, vol. 499, pp. 41-46, 2003.
[29] C. Yang and Z. Zhang, "A novel flow-injection chemiluminescence determination of uric acid based on diperiodatoargentate(III) oxidation," Talanta, vol. 81, pp. 477-481, 2010.
[30] M. R. Moghadam, S. Dadfarnia, A. M. H. Shabani, and P. Shahbazikhah, "Chemometric-assisted kinetic–spectrophotometric method for simultaneous determination of ascorbic acid, uric acid, and dopamine," Anal. Biochem., vol. 410, pp. 289-295, 2011.
[31] L. Yang, D. Liu, J. Huang, and T. You, "Simultaneous determination of dopamine, ascorbic acid and uric acid at electrochemically reduced graphene oxide modified electrode," Sens. Actuators B, vol. 193, pp. 166-172, 2014.
[32] G. Wang, J. Meng, H. Liu, S. Jiao, W. Zhang, D. Chen, and B. Fang, "Determination of uric acid in the presence of ascorbic acid with hexacyanoferrate lanthanum film modified electrode," Electrochim. Acta, vol. 53, pp. 2837-2843, 2008.
[33] M. Noroozifar, M. Khorasani-Motlagh, H. Hassani Nadiki, M. Saeed Hadavi, and M. Mehdi Foroughi, "Modified fluorine-doped tin oxide electrode with inorganic ruthenium red dye-multiwalled carbon nanotubes for simultaneous determination of a dopamine, uric acid, and tryptophan," Sens. Actuators B, vol. 204, pp. 333-341, 2014.
[34] F. Zhang, J. Tang, Z. Wang, and L. C. Qin, "Graphene-carbon nanotube composite aerogel for selective detection of uric acid," Chem. Phys. Lett., vol. 590, pp. 121-125, 2013.
[35] S. Y. Yi, J. H. Lee, and H. G. Hong, "A selective determination of levodopa in the presence of ascorbic acid and uric acid using a glassy carbon electrode modified with reduced graphene oxide," J. Appl. Electrochem., vol. 44, pp. 589-597, 2014.
[36] T. Thomas, R. J. Mascarenhas, P. Martis, Z. Mekhalif, and B. E. K. Swamy, "Multi-walled carbon nanotube modified carbon paste electrode as an electrochemical sensor for the determination of epinephrine in the presence of ascorbic acid and uric acid," Mater. Sci. Eng. C, vol. 33, pp. 3294-3302, 2013.
[37] M. Rutkowski and K. Grzegorczyk, "Vitamin C in medicine: "normal concentration" in serum," (in Polish), Pol. Merkur. Lekarski., vol. 6, pp. 57-60, 1999.
[38] D. J. VanderJagt, P. J. Garry, and H. N. Bhagavan, "Ascorbic acid intake and plasma levels in healthy elderly people," Am. J. Clin. Nutr., vol. 46, pp. 290-294, 1987.
[39] N. J. Christensen, C. J. Mathias, and H. L. Frankel, "Plasma and urinary dopamine studies during fasting and exercise and in tetraplegic man," Eur. J. Clin. Invest., vol. 6, pp. 403-409, 1976.
[40] C. B. Jacobs, M. J. Peairs, and B. J. Venton, "Review: Carbon nanotube based electrochemical sensors for biomolecules," Anal. Chim. Acta, vol. 662, pp. 105-127, 2010.
[41] E. A. Khudaish, K. Y. Al-Ajmi, and S. H. Al-Harthi, "A solid-state sensor based on ruthenium (II) complex immobilized on polytyramine film for the simultaneous determination of dopamine, ascorbic acid and uric acid," Thin Solid Films, vol. 564, pp. 390-396, 2014.
[42] X. Zhang, L.-X. Ma, and Y.-C. Zhang, "Electrodeposition of platinum nanosheets on C60 decorated glassy carbon electrode as a stable electrochemical biosensor for simultaneous detection of ascorbic acid, dopamine and uric acid," Electrochim. Acta, to be published.
[43] H. Zhang, X. Wang, L. Wan, Y. Liu, and C. Bai, "Electrochemical behavior of multi-wall carbon nanotubes and electrocatalysis of toluene-filled nanotube film on gold electrode," Electrochim. Acta, vol. 49, pp. 715-719, 2004.
[44] Z. Gao and H. Huang, "Simultaneous determination of dopamine, uric acid and ascorbic acid at an ultrathin film modified gold electrode," Chem. Commun., pp. 2107-2108, 1998.
[45] A. S. Kumar and P. Swetha, "Ru(DMSO)4Cl2 nano-aggregated Nafion membrane modified electrode for simultaneous electrochemical detection of hypoxanthine, xanthine and uric acid," J. Electroanal. Chem., vol. 642, pp. 135-142, 2010.
[46] A.-L. Liu, S.-B. Zhang, W. Chen, X.-H. Lin, and X.-H. Xia, "Simultaneous voltammetric determination of norepinephrine, ascorbic acid and uric acid on polycalconcarboxylic acid modified glassy carbon electrode," Biosens. Bioelectron., vol. 23, pp. 1488-1495, 2008.
[47] C. A. S. Ballesteros, J. Cancino, V. S. Marangoni, and V. Zucolotto, "Nanostructured Fe3O4 satellite gold nanoparticles to improve biomolecular detection," Sens. Actuators, B, vol. 198, pp. 377-383, 2014.
[48] G. Fabregat, E. Armelin, and C. Alemán, "Selective detection of dopamine combining multilayers of conducting polymers with gold nanoparticles," J. Phys. Chem. B, vol. 118, pp. 4669-4682, 2014.
[49] A. Benvidi, A. Dehghani-Firouzabadi, M. Mazloum-Ardakani, B. B. F. Mirjalili, and R. Zare, "Electrochemical deposition of gold nanoparticles on reduced graphene oxide modified glassy carbon electrode for simultaneous determination of levodopa, uric acid and folic acid," J. Electroanal. Chem., vol. 736, pp. 22-29, 2015.
[50] N. Pires, T. Dong, U. Hanke, and N. Hoivik, "Recent Developments in Optical Detection Technologies in Lab-on-a-Chip Devices for Biosensing Applications," Sensors, vol. 14, pp. 15458-15479, 2014.
[51] S. Zhao, X. Lan, and Y.-M. Liu, "Gold nanoparticles - enhanced capillary electrophoresis- chemiluminescence assay of trace uric acid," Electrophoresis, vol. 30, pp. 2676-2680, 2009.
[52] S. Pennathur and D. K. Fygenson, "Improving fluorescence detection in lab on chip devices," Lab Chip, vol. 8, pp. 649-652, 2008.
[53] N. Wongkaew, P. He, V. Kurth, W. Surareungchai, and A. Baeumner, "Multi-channel PMMA microfluidic biosensor with integrated IDUAs for electrochemical detection," Anal. Bioanal. Chem., vol. 405, pp. 5965-5974, 2013.
[54] L. C. Jiang and W. D. Zhang, "Electroanalysis of dopamine at RuO2 modified vertically aligned carbon nanotube electrode," Electroanalysis, vol. 21, pp. 1811-1815, 2009.
[55] L. Wu, L. Feng, J. Ren, and X. Qu, "Electrochemical detection of dopamine using porphyrin-functionalized graphene," Biosens. Bioelectron., vol. 34, pp. 57-62, 2012.
[56] Y.-T. Shih, K.-Y. Lee, and Y.-S. Huang, "Electrochemical capacitance characteristics of patterned ruthenium dioxide-carbon nanotube nanocomposites grown onto graphene," Appl. Surf. Sci., vol. 294, pp. 29-35, 2014.
[57] A. A. Bolzan, C. Fong, B. J. Kennedy, and C. J. Howard, "Structural Studies of Rutile-Type Metal Dioxides," Acta Crystallogr. Sect. B, vol. 53, pp. 373-380, 1997.
[58] P. I. Sorantin and K. Schwarz, "Chemical bonding in rutile-type compounds," Inorg. Chem., vol. 31, pp. 567-576, 1992.
[59] W. D. Ryden, A. W. Lawson, and C. C. Sartain, "Electrical transport properties of IrO2 and RuO2," Phys. Rev. B, vol. 1, pp. 1494-1500, 1970.
[60] A. T. Kuhn and C. J. Mortimer, "The Kinetics of Chlorine Evolution and Reduction on Titanium‐Supported Metal Oxides Especially RuO2 and IrO2," J. Electrochem. Soc., vol. 120, pp. 231-236, 1973.
[61] J. C. Cruz, V. Baglio, S. Siracusano, V. Antonucci, A. S. Aricò, R. Ornelas, L. Ortiz-Frade, G. Osorio-Monreal, S. M. Durón-Torres, and L. G. Arriaga, "Preparation and characterization of RuO2 catalysts for oxygen evolution in a solid polymer electrolyte," Int. J. Electrochem. Sci., vol. 6, pp. 6607-6619, 2011.
[62] H. Xia, Y. S. Meng, G. Yuan, C. Cui, and L. Lu, "A Symmetric RuO2/RuO2 Supercapacitor Operating at 1.6 V by Using a Neutral Aqueous Electrolyte," Electrochem. Solid-State Lett., vol. 15, pp. A60-A63, 2012.
[63] T. Audichon, E. Mayousse, S. Morisset, C. Morais, C. Comminges, T. W. Napporn, and K. B. Kokoh, "Electroactivity of RuO2–IrO2 mixed nanocatalysts toward the oxygen evolution reaction in a water electrolyzer supplied by a solar profile," Int. J. Hydrogen Energy, vol. 39, pp. 16785-16796, 2014.
[64] L.-Å. Näslund, Á. S. Ingason, S. Holmin, and J. Rosen, "Formation of RuO(OH)2 on RuO2-Based Electrodes for Hydrogen Production," J. Phys. Chem. C, vol. 118, pp. 15315-15323, 2014.
[65] L. Krusin‐Elbaum, M. Wittmer, and D. S. Yee, "Characterization of reactively sputtered ruthenium dioxide for very large scale integrated metallization," Appl. Phys. Lett., vol. 50, pp. 1879-1881, 1987.
[66] Q. X. Jia, L. H. Chang, and W. A. Anderson, "Surface and interface properties of ferroelectric BaTiO3 thin films on Si using RuO2 as an electrode," J. Mater. Res., vol. 9, pp. 2561-2565, 1994.
[67] D. Ferizović, L. K. Hussey, Y.-S. Huang, and M. Muñoz, "Determination of the room temperature thermal conductivity of RuO2 by the photothermal deflection technique," Appl. Phys. Lett., vol. 94, p. 131913, 2009.
[68] M. Ramani, B. S. Haran, R. E. White, B. N. Popov, and L. Arsov, "Studies on activated carbon capacitor materials loaded with different amounts of ruthenium oxide," J. Power Sources, vol. 93, pp. 209-214, 2001.
[69] Y. L. Chueh, C. H. Hsieh, M. T. Chang, L. J. Chou, C. S. Lao, J. H. Song, J. Y. Gan, and Z. L. Wang, "RuO2 nanowires and RuO2/TiO2 core/shell nanowires: From synthesis to mechanical, optical, electrical, and photoconductive properties," Adv. Mater., vol. 19, pp. 143-149, 2007.
[70] S. Iijima, "Helical microtubules of graphitic carbon," Nature, vol. 354, pp. 56-58, 1991.
[71] R. Saito, Physical Properties of Carbon Nanotubes, London: Imerial College Press, 1998.
[72] A. Thess, R. Lee, P. Nikolaev, H. Dai, P. Petit, J. Robert, C. Xu, Y. H. Lee, S. G. Kim, A. G. Rinzler, D. T. Colbert, G. E. Scuseria, D. Tománek, J. E. Fischer, and R. E. Smalley, "Crystalline Ropes of Metallic Carbon Nanotubes," Science, vol. 273, pp. 483-487, 1996.
[73] S. Hong and S. Myung, "Nanotube Electronics: A flexible approach to mobility," Nat. Nano, vol. 2, pp. 207-208, 2007.
[74] X. Lu and Z. Chen, "Curved Pi-Conjugation, Aromaticity, and the Related Chemistry of Small Fullerenes (<C60) and Single-Walled Carbon Nanotubes," Chem. Rev., vol. 105, pp. 3643-3696, 2005.
[75] I. Stavarache, A.-M. Lepadatu, V. Teodorescu, M. Ciurea, V. Iancu, M. Dragoman, G. Konstantinidis, and R. Buiculescu, "Electrical behavior of multi-walled carbon nanotube network embedded in amorphous silicon nitride," Nanoscale Res. Lett., vol. 6, p. 88, 2011.
[76] M. Shiraishi and M. Ata, "Work function of carbon nanotubes," Carbon, vol. 39, pp. 1913-1917, 2001.
[77] S. Kazaoui, N. Minami, N. Matsuda, H. Kataura, and Y. Achiba, "Electrochemical tuning of electronic states in single-wall carbon nanotubes studied by in situ absorption spectroscopy and ac resistance," Appl. Phys. Lett., vol. 78, pp. 3433-3435, 2001.
[78] K. S. Novoselov, A. K. Geim, S. V. Morozov, D. Jiang, Y. Zhang, S. V. Dubonos, I. V. Grigorieva, and A. A. Firsov, "Electric field in atomically thin carbon films," Science, vol. 306, pp. 666-669, 2004.
[79] J. Hass, W. A. De Heer, and E. H. Conrad, "The growth and morphology of epitaxial multilayer graphene," J. Phys.: Condens. Matter, vol. 20, 2008.
[80] A. H. Castro Neto, F. Guinea, N. M. R. Peres, K. S. Novoselov, and A. K. Geim, "The electronic properties of graphene," Rev. Mod. Phys., vol. 81, pp. 109-162, 2009.
[81] M. Burghard, H. Klauk, and K. Kern, "Carbon-based field-effect transistors for nanoelectronics," Adv. Mater., vol. 21, pp. 2586-2600, 2009.
[82] K. I. Bolotin, K. J. Sikes, Z. Jiang, M. Klima, G. Fudenberg, J. Hone, P. Kim, and H. L. Stormer, "Ultrahigh electron mobility in suspended graphene," Solid State Commun., vol. 146, pp. 351-355, 2008.
[83] H. Wang, T. Maiyalagan, and X. Wang, "Review on recent progress in nitrogen-doped graphene: Synthesis, characterization, and its potential applications," ACS Catal., vol. 2, pp. 781-794, 2012.
[84] X. D. Chen, Z. B. Liu, C. Y. Zheng, F. Xing, X. Q. Yan, Y. Chen, and J. G. Tian, "High-quality and efficient transfer of large-area graphene films onto different substrates," Carbon, vol. 56, pp. 271-278, 2013.
[85] X. Wang, X. Li, L. Zhang, Y. Yoon, P. K. Weber, H. Wang, J. Guo, and H. Dai, "N-doping of graphene through electrothermal reactions with ammonia," Science, vol. 324, pp. 768-771, 2009.
[86] D. Wei, Y. Liu, Y. Wang, H. Zhang, L. Huang, and G. Yu, "Synthesis of n-doped graphene by chemical vapor deposition and its electrical properties," Nano Lett., vol. 9, pp. 1752-1758, 2009.
[87] S. Stankovich, D. A. Dikin, G. H. B. Dommett, K. M. Kohlhaas, E. J. Zimney, E. A. Stach, R. D. Piner, S. T. Nguyen, and R. S. Ruoff, "Graphene-based composite materials," Nature, vol. 442, pp. 282-286, 2006.
[88] D. A. Dikin, S. Stankovich, E. J. Zimney, R. D. Piner, G. H. B. Dommett, G. Evmenenko, S. T. Nguyen, and R. S. Ruoff, "Preparation and characterization of graphene oxide paper," Nature, vol. 448, pp. 457-460, 2007.
[89] S. Subrina and D. Kotchetkov, "Simulation of Heat Conduction in Suspended Graphene Flakes of Variable Shapes," J. Nanoelectron. Optoelectron., vol. 3, pp. 249-269, 2008.
[90] A. A. Balandin, S. Ghosh, W. Bao, I. Calizo, D. Teweldebrhan, F. Miao, and C. N. Lau, "Superior Thermal Conductivity of Single-Layer Graphene," Nano Lett., vol. 8, pp. 902-907, 2008.
[91] E. Pop, V. Varshney, and A. K. Roy, "Thermal properties of graphene: Fundamentals and applications," MRS Bull., vol. 37, pp. 1273-1281, 2012.
[92] J. F. Dai, G. J. Wang, L. Ma, and C. K. Wu, "Surface properties of graphene: Relationship to graphene-polymer composites," Rev. Adv. Mater. Sci., vol. 40, pp. 60-71, 2015.
[93] A. K. Geim and K. S. Novoselov, "The rise of graphene," Nat. Mater., vol. 6, pp. 183-191, 2007.
[94] P. J. Britto, K. S. V. Santhanam, and P. M. Ajayan, "Carbon nanotube electrode for oxidation of dopamine," Bioelectrochem. Bioenerg., vol. 41, pp. 121-125, 1996.
[95] S. C. Tsang, Y. K. Chen, P. J. F. Harris, and M. L. H. Green, "A simple chemical method of opening and filling carbon nanotubes," Nature, vol. 372, pp. 159-162, 1994.
[96] H. Hiura, T. W. Ebbesen, and K. Tanigaki, "Opening and purification of carbon nanotubes in high yields," Adv. Mater., vol. 7, pp. 275-276, 1995.
[97] C. E. Banks and R. G. Compton, "New electrodes for old: From carbon nanotubes to edge plane pyrolytic graphite," Analyst, vol. 131, pp. 15-21, 2006.
[98] T. Rohani and M. A. Taher, "Novel functionalized multiwalled carbon nanotube-glassy carbon electrode for simultaneous determination of ascorbic acid and uric acid," Arab. J. Chem., to be published.
[99] K. C. Lin, Y. S. Li, and S. M. Chen, "Carboxy-functionalized multi-walled carbon nanotubes hybridized with poly(xanthurenic acid) enhance the electrocatalytic oxidation of ascorbic acid, dopamine, and uric acid," Int. J. Electrochem. Sci., vol. 10, pp. 2764-2775, 2015.
[100] L. Yi-Hung and C. Jung-Chuan, "Potentiometric Multisensor Based on Ruthenium Dioxide Thin Film With a Bluetooth Wireless and Web-Based Remote Measurement System," IEEE Sens. J., vol. 9, pp. 1887-1894, 2009.
[101] R. M. A. Tehrani and S. Ab Ghani, "MWCNT-ruthenium oxide composite paste electrode as non-enzymatic glucose sensor," Biosens. Bioelectron., vol. 38, pp. 278-283, 2012.
[102] R. M. Westervelt, "Applied physics: Graphene nanoelectronics," Science, vol. 320, pp. 324-325, 2008.
[103] H. Gwon, H. S. Kim, K. U. Lee, D. H. Seo, Y. C. Park, Y. S. Lee, B. T. Ahn, and K. Kang, "Flexible energy storage devices based on graphene paper," Energ. Environ. Sci., vol. 4, pp. 1277-1283, 2011.
[104] N. Mohanty and V. Berry, "Graphene-based single-bacterium resolution biodevice and DNA transistor: Interfacing graphene derivatives with nanoscale and microscale biocomponents," Nano Lett., vol. 8, pp. 4469-4476, 2008.
[105] M. Zhou, Y. Zhai, and S. Dong, "Electrochemical sensing and biosensing platform based on chemically reduced graphene oxide," Anal. Chem., vol. 81, pp. 5603-5613, 2009.
[106] C. Shan, H. Yang, D. Han, Q. Zhang, A. Ivaska, and L. Niu, "Graphene/AuNPs/chitosan nanocomposites film for glucose biosensing," Biosens. Bioelectron., vol. 25, pp. 1070-1074, 2010.
[107] J. Kailashiya, N. Singh, S. K. Singh, V. Agrawal, and D. Dash, "Graphene oxide-based biosensor for detection of platelet-derived microparticles: A potential tool for thrombus risk identification," Biosens. Bioelectron., vol. 65, pp. 274-280, 2015.
[108] H. Huang, W. Bai, C. Dong, R. Guo, and Z. Liu, "An ultrasensitive electrochemical DNA biosensor based on graphene/Au nanorod/polythionine for human papillomavirus DNA detection," Biosens. Bioelectron., vol. 68, pp. 442-446, 2015.
[109] J. Du, R. Yue, F. Ren, Z. Yao, F. Jiang, P. Yang, and Y. Du, "Simultaneous determination of uric acid and dopamine using a carbon fiber electrode modified by layer-by-layer assembly of graphene and gold nanoparticles," Gold Bull., vol. 46, pp. 137-144, 2013.
[110] B. W. Kwak, Y. C. Choi, and B. S. Lee, "Small variations in the sheet resistance of graphene layers with compressive and tensile bending," Physica E, vol. 68, pp. 33-37, 2015.
[111] X.-D. Chen, Z.-B. Liu, W.-S. Jiang, X.-Q. Yan, F. Xing, P. Wang, Y. Chen, and J.-G. Tian, "The selective transfer of patterned graphene," Sci. Rep., vol. 3, 2013.
[112] X. Li, Y. Zhu, W. Cai, M. Borysiak, B. Han, D. Chen, R. D. Piner, L. Colomba, and R. S. Ruoff, "Transfer of large-area graphene films for high-performance transparent conductive electrodes," Nano Lett., vol. 9, pp. 4359-4363, 2009.
[113] C. Ma, X. Wang, Y. Ma, J. Sheng, Y. Li, S. Li, and J. Shi, "Carbon nanofiber/graphene composite paper for flexible supercapacitors with high volumetric capacitance," Mater. Lett., vol. 145, pp. 197-200, 2015.
[114] L. Wei, W. Jiang, Y. Yuan, K. Goh, D. Yu, L. Wang, and Y. Chen, "Synthesis of free-standing carbon nanohybrid by directly growing carbon nanotubes on air-sprayed graphene oxide paper and its application in supercapacitor," J. Solid State Chem., vol. 224, pp. 45-51, 2015.
[115] L.-L. Xu, M.-X. Guo, S. Liu, and S.-W. Bian, "Graphene/cotton composite fabrics as flexible electrode materials for electrochemical capacitors," RSC Adv., vol. 5, pp. 25244-25249, 2015.
[116] S. Dong, J. Xi, Y. Wu, H. Liu, C. Fu, H. Liu, and F. Xiao, "High loading MnO2 nanowires on graphene paper: Facile electrochemical synthesis and use as flexible electrode for tracking hydrogen peroxide secretion in live cells," Anal. Chim. Acta, vol. 853, pp. 200-206, 2015.
[117] A. Salimi, R. Hallaj, and G. R. Khayatian, "Amperometric detection of morphine at preheated glassy carbon electrode modified with multiwall carbon nanotubes," Electroanalysis, vol. 17, pp. 873-879, 2005.
[118] J. S. Ye, Y. Wen, W. D. Zhang, L. M. Gan, G. Q. Xu, and F. S. Sheu, "Nonenzymatic glucose detection using multi-walled carbon nanotube electrodes," Electrochem. Commun., vol. 6, pp. 66-70, 2004.
[119] J. S. Ye, Y. Wen, W. D. Zhang, L. M. Gan, G. Q. Xu, and F. S. Sheu, "Selective Voltammetric Detection of Uric Acid in the Presence of Ascorbic Acid at Well-Aligned Carbon Nanotube Electrode," Electroanalysis, vol. 15, pp. 1693-1698, 2003.
[120] J. Wang and M. Musameh, "Electrochemical detection of trace insulin at carbon-nanotube-modified electrodes," Anal. Chim. Acta, vol. 511, pp. 33-36, 2004.
[121] G. Liu, Y. Lin, Y. Tu, and Z. Ren, "Ultrasensitive voltammetric detection of trace heavy metal ions using carbon nanotube nanoelectrode array," Analyst, vol. 130, pp. 1098-1101, 2005.
[122] F. H. Wu, G. C. Zhao, and X. W. Wei, "Electrocatalytic oxidation of nitric oxide at multi-walled carbon nanotubes modified electrode," Electrochem. Commun., vol. 4, pp. 690-694, 2002.
[123] S. Mitani, S.-I. Lee, K. Saito, Y. Korai, and I. Mochida, "Contrast structure and EDLC performances of activated spherical carbons with medium and large surface areas," Electrochim. Acta, vol. 51, pp. 5487-5493, 2006.
[124] Y. Zhai, Y. Dou, D. Zhao, P. F. Fulvio, R. T. Mayes, and S. Dai, "Carbon Materials for Chemical Capacitive Energy Storage," Adv. Mater., vol. 23, pp. 4828-4850, 2011.
[125] J. R. Miller, "Introduction to electrochemical capacitor technology," IEEE Electr. Insul. Mag., vol. 26, pp. 40-47, 2010.
[126] W.-D. Zhang, B. Xu, and L.-C. Jiang, "Functional hybrid materials based on carbon nanotubes and metal oxides," J. Mater. Chem., vol. 20, pp. 6383-6391, 2010.
[127] L. Diederich, E. Barborini, P. Piseri, A. Podestà, P. Milani, A. Schneuwly, and R. Gallay, "Supercapacitors based on nanostructured carbon electrodes grown by cluster-beam deposition," Appl. Phys. Lett., vol. 75, pp. 2662-2664, 1999.
[128] Z. Fan, J. Chen, K. Cui, F. Sun, Y. Xu, and Y. Kuang, "Preparation and capacitive properties of cobalt–nickel oxides/carbon nanotube composites," Electrochim. Acta, vol. 52, pp. 2959-2965, 2007.
[129] Y. M. Chen, C. A. Chen, Y. S. Huang, K. Y. Lee, and K. K. Tiong, "Synthesis of IrO2 nanocrystals on carbon nanotube bundle arrays and their field emission characteristics," J. Alloys Compd., vol. 487, pp. 659-664, 2009.
[130] C.-C. Liu, D.-S. Tsai, D. Susanti, W.-C. Yeh, Y.-S. Huang, and F.-J. Liu, "Planar ultracapacitors of miniature interdigital electrode loaded with hydrous RuO2 and RuO2 nanorods," Electrochim. Acta, vol. 55, pp. 5768-5774, 2010.
[131] Y. M. Chen, J. H. Cai, Y. S. Huang, K. Y. Lee, and D. S. Tsai, "Preparation and characterization of iridium dioxide-carbon nanotube nanocomposites for supercapacitors," Nanotechnology, vol. 22, 2011.
[132] U. M. Patil, R. R. Salunkhe, K. V. Gurav, and C. D. Lokhande, "Chemically deposited nanocrystalline NiO thin films for supercapacitor application," Appl. Surf. Sci., vol. 255, pp. 2603-2607, 2008.
[133] G. H. Deng, X. Xiao, J. H. Chen, X. B. Zeng, D. L. He, and Y. F. Kuang, "A new method to prepare RuO2•xH2O/carbon nanotube composite for electrochemical capacitors," Carbon, vol. 43, pp. 1566-1569, 2005.
[134] S. Stankovich, D. A. Dikin, R. D. Piner, K. A. Kohlhaas, A. Kleinhammes, Y. Jia, Y. Wu, S. T. Nguyen, and R. S. Ruoff, "Synthesis of graphene-based nanosheets via chemical reduction of exfoliated graphite oxide," Carbon, vol. 45, pp. 1558-1565, 2007.
[135] J. H. Chen, W. Z. Li, D. Z. Wang, S. X. Yang, J. G. Wen, and Z. F. Ren, "Electrochemical characterization of carbon nanotubes as electrode in electrochemical double-layer capacitors," Carbon, vol. 40, pp. 1193-1197, 2002.
[136] M. Li, W. Guo, H. Li, W. Dai, and B. Yang, "Electrochemical biosensor based on one-dimensional MgO nanostructures for the simultaneous determination of ascorbic acid, dopamine, and uric acid," Sens. Actuators B, vol. 204, pp. 629-636, 2014.
[137] K. F. Drake, R. P. Van Duyne, and A. M. Bond, "Cyclic differential pulse voltammetry: A versatile instrumental approach using a computerized system," J. Electroanal. Chem. Interfac., vol. 89, pp. 231-246, 1978.
[138] K. Aoki, J. Osteryoung, and R. A. Osteryoung, "Differential normal pulse voltammetry-theory," J. Electroanal. Chem. Interfac., vol. 110, pp. 1-18, 1980.
[139] M. S. Dresselhaus, G. Dresselhaus, R. Saito, and A. Jorio, "Raman spectroscopy of carbon nanotubes," Phys. Rep., vol. 409, pp. 47-99, 2005.
[140] A. Jorio, A. G. Souza Filho, G. Dresselhaus, M. S. Dresselhaus, A. K. Swan, M. S. Ünlü, B. B. Goldberg, M. A. Pimenta, J. H. Hafner, C. M. Lieber, and R. Saito, "G-band resonant Raman study of 62 isolated single-wall carbon nanotubes," Phys. Rev. B: Condens. Matter., vol. 65, pp. 1554121-1554129, 2002.
[141] P. M. Ajayan, "Nanotubes from Carbon," Chem. Rev., vol. 99, pp. 1787-1799, 1999.
[142] T. W. Ebbesen, "Carbon nanotubes," Phys. Today, vol. 49, pp. 26-32, 1996.
[143] M. S. Dresselhaus, A. Jorio, M. Hofmann, G. Dresselhaus, and R. Saito, "Perspectives on carbon nanotubes and graphene Raman spectroscopy," Nano Lett., vol. 10, pp. 751-758, 2010.
[144] S. Bhaskar, P. S. Dobal, S. B. Majumder, and R. S. Katiyar, "X-ray photoelectron spectroscopy and micro-Raman analysis of conductive RuO2 thin films," J. Appl. Phys., vol. 89, pp. 2987-2992, 2001.
[145] J. Du, R. Yue, Z. Yao, F. Jiang, Y. Du, P. Yang, and C. Wang, "Nonenzymatic uric acid electrochemical sensor based on graphene-modified carbon fiber electrode," Colloids Surf. A, vol. 419, pp. 94-99, 2013.
[146] P. T. Kissinger and W. R. Heineman, Laboratory Techniques in Electroanalytical Chemistry, New York: Marcel Dekker, 1996.
[147] H. Bi, Y. Li, S. Liu, P. Guo, Z. Wei, C. Lv, J. Zhang, and X. S. Zhao, "Carbon-nanotube-modified glassy carbon electrode for simultaneous determination of dopamine, ascorbic acid and uric acid: The effect of functional groups," Sens. Actuators B, vol. 171–172, pp. 1132-1140, 2012.
[148] Y. J. Yang and W. Li, "CTAB functionalized graphene oxide/multiwalled carbon nanotube composite modified electrode for the simultaneous determination of ascorbic acid, dopamine, uric acid and nitrite," Biosens. Bioelectron., vol. 56, pp. 300-306, 2014.
[149] D. A. C. Brownson, R. V. Gorbachev, S. J. Haigh, and C. E. Banks, "CVD graphene vs. highly ordered pyrolytic graphite for use in electroanalytical sensing," Analyst, vol. 137, pp. 833-839, 2012.
[150] M. Hiramatsu, K. Shiji, H. Amano, and M. Hori, "Fabrication of vertically aligned carbon nanowalls using capacitively coupled plasma-enhanced chemical vapor deposition assisted by hydrogen radical injection," Appl. Phys. Lett., vol. 84, pp. 4708-4710, 2004.
[151] C. C. Chiu, M. Yoshimura, and K. Ueda, "Regrowth of carbon nanotube array by microwave plasma-enhanced thermal chemical vapor deposition," Jpn. J. Appl. Phys., vol. 47, pp. 1952-1955, 2008.
[152] A. C. Ferrari, J. C. Meyer, V. Scardaci, C. Casiraghi, M. Lazzeri, F. Mauri, S. Piscanec, D. Jiang, K. S. Novoselov, S. Roth, and A. K. Geim, "Raman Spectrum of Graphene and Graphene Layers," Phys. Rev. Lett., vol. 97, p. 187401, 2006.
[153] M. H. Kim, J. M. Baik, S. J. Lee, H. Y. Shin, J. Lee, S. Yoon, G. D. Stucky, M. Moskovits, and A. M. Wodtke, "Growth direction determination of a single RuO2 nanowire by polarized Raman spectroscopy," Appl. Phys. Lett., vol. 96, 2010.
[154] C. Zhang, Z. Peng, J. Lin, Y. Zhu, G. Ruan, C. C. Hwang, W. Lu, R. H. Hauge, and J. M. Tour, "Splitting of a vertical multiwalled carbon nanotube carpet to a graphene nanoribbon carpet and its use in supercapacitors," ACS Nano, vol. 7, pp. 5151-5159, 2013.
[155] Y. S. Kim, K. Kumar, F. T. Fisher, and E. H. Yang, "Out-of-plane growth of CNTs on graphene for supercapacitor applications," Nanotechnology, vol. 23, 2012.
[156] T. Lu, L. Pan, H. Li, C. Nie, M. Zhu, and Z. Sun, "Reduced graphene oxide-carbon nanotubes composite films by electrophoretic deposition method for supercapacitors," J. Electroanal. Chem., vol. 661, pp. 270-273, 2011.
[157] Y. F. Li, Y. Z. Liu, Y. G. Yang, M. Z. Wang, and Y. F. Wen, "Reduced graphene oxide/MWCNT hybrid sandwiched film by self-assembly for high performance supercapacitor electrodes," Appl. Phys. A, vol. 108, pp. 701-707, 2012.
[158] B. E. Conway, "Transition from 'supercapacitor' to 'battery' behavior in electrochemical energy storage," J. Electrochem. Soc., vol. 138, pp. 1539-1548, 1991.