人的體內會因為L-半胱氨酸(L-cys)濃度異常而引發各種疾病，因此本研究以簡單、準確、快速檢測的電化學方式結合玻璃碳電極(GCE)及可拋棄式金電極(AuE)測定L-cys的濃度。然而，直接使用GCE和AuE會使感測的靈敏度不足，故本研究使用兩種不同的系統分別修飾GCE及AuE以達到高感測靈敏度。
第一個系統為製備普魯士藍-殼聚醣混和物(PB-Chi)與銅-銀纖維複合材料(500-Ag-Cu/PVP)並將兩者修飾於GCE表層(Cu-Ag-PB-Chi/GCE)，第二個系統以電鍍方式將銅沉積於金電極表面(Cu/AuE)。
本論文第一部分利用電紡絲製備PVP纖維，並且將PVP纖維硫醇官能化 (thiol-functionalization)，在500 oC下將銀還原於PVP纖維上，再以化學鍍銅方式將500-Ag-Cu/PVP製備而成。而GCE的修飾層是將已製備出的500-Ag/PVP 、500-Ag-Cu/PVP、化學合成PB，及殼聚醣溶液，用於製備三種不同的修飾GCE ( PB-Chi，Ag-PB-Chi，以及Cu-Ag-PB-Chi/ GCE)。
利用SEM觀察熱燒結含有銀離子之PVP纖維(Ag+-RSH-CL-PVP fibers)，依然存在絲狀結構。同時可以觀察到，經過銅化學鍍層法製備出的500-Ag-Cu/PVP複合纖維較500-Ag/PVP纖維平均直徑大。透過FTIR分析可觀察到Si-O-Si以及Si-O-CH3官能基訊號，由此可說明硫醇官能化反應成功。更利用XRD觀察500-Ag/PVP纖維與500-Ag-Cu/PVP複合纖維的結晶型態，由訊號結果可得到Ag和Cu良好的結晶性。
將三種不同的修飾GCE分別利用循環伏安法去檢測L-cys，從循環伏安法結果得知，L-cys的感測能力分別為Cu-Ag-PB-Chi/GCE > Ag-PB-Chi/GCE > PB-Chi/GCE。有這樣的改善結果是由於，500-Ag-Cu/PVP複合纖維中的Ag-Cu協同效應和對於L-cys有好的氧化催化效果。在電化學測試結果中可以找到兩線性範圍及相對靈敏度，分別為40-1800 µM : 0.1501 µA.µM-1cm-2以及1800-2500 M : 0.0707µA.µM-1cm-2，並可計算出最低偵測極限為1.42 M。此外，在抗干擾測試中發現Cu-Ag-PB-Chi/GCE對L-cys有很高的專一性，且不受sucrose、 glucose、 citric acid、 oxalic acid、 urea、 EDTA以及uric acid的影響。
本論文第二部分為利用Cu/AuE感測L-cys，Cu/AuE主要將金電極浸泡於含銅之水溶液，並利用恆電位沉積法使銅離子沉積在金電極上面，以製備出Cu/AuE。透過XRD與SEM做表面形態以及結晶性分析。從SEM表面特性分析中可以證明，銅電鍍層會受到電化學條件(如: 供應電流、沉積時間)以及前驅物組成溶液(如: CuSO4以及Na2SO4濃度比例不同)的影響，進而發現在沉積時間大於480秒會有較均勻的銅層覆蓋；此外，在較高的供應電流下銅會有樹突狀結構形成。在XRD的分析中可以確認，利用電化學沉積方法成功地將銅沉積在金電極表面。透過最適化測試，可以找出在供應電流為-0.4 V下沉積480秒有最高的電流響應。而製備出的Cu/AuE也利用循環伏安法做電化學特性的測試。根據循環伏安法的測試結果可以看出，Cu/AuE在0.1 M NaOH鹼性溶液中，對L-cys有較好的電催化活性。而最適化參數下Cu/AuE有最小的偵測極限約為0.21 M，並可以找到兩段線性範圍及其相對靈敏度，分別為1-400 µM : 1.0493 µA.µM-1.cm-2以及 400-1800 µM : 0.5090 µA.µM-1.cm-2。此外，在抗干擾測試中發現Cu/AuE對L-cys有很高的專一性，且不受sucrose、 glucose、 citric acid、 oxalic acid、 urea、 EDTA，以及uric acid的影響。

The development of effective strategy to perform electrochemical determination of l-cysteine (L-cys) is of great importance for physiological and clinical diagnosis of various diseases owing to the abnormal level of L-cys. In this study, the application of electrochemical method aim to perform simple, accurate, and fast detection of L-cys using glassy carbon (GCE) and gold electrodes (AuE).
Since direct use of bare GCE and AuE possessed problems of insufficient sensitivity and specificity, two designs of sensors for electrochemical determination of L-cys which are copper-silver fibers composite (500-Ag-Cu/PVP fibers) incorporated in Prussian blue-chitosan modified on GCE (Cu-Ag-PB-Chi/GCE) and copper electrodeposited on AuE (Cu/AuE) were prepared in order to address those problems. The modified layer of GCE was made under three steps: (1) preparation of 500-Ag-Cu/PVP fibers involving electrospinning, crosslinking, thiol-functionalization, silver-ions loading, heat reduction and copper electroless plating, (2) chemical synthesis of PB, and (3) preparation of chitosan solution (Chi). The as-prepared 500-Ag/PVP fibers, 500-Ag-Cu/PVP fibers, chemically synthesized PB, and Chi were used to fabricate: PB-Chi, Ag-PB–Chi, and Cu-Ag-PB–Chi/ GCE.
The surface modification on the electrodes were evaluated by different analytical methods. Surface morphology observation by SEM revealed that after heat reduction allow to load silver-ions on PVP fibers (Ag+-RSH-CL-PVP fibers), where the structure of fibers was maintained. Meanwhile, by means of copper electroless plating, the 500-Ag-Cu/PVP fibers which possessed thicker average diameter than 500-Ag/PVP fibers was generated. The thiol-functionalization process was confirmed by FTIR that the peaks corresponded to the functional group of Si-O-Si and Si-O-CH3 were found. Moreover, XRD pattern results declared that the as-prepared 500-Ag/PVP and 500-Ag-Cu/PVP fibers reveal the crystalline phases of Ag and both Cu and Ag, respectively.
The three modified GCE were characterized by cyclic voltammetry to investigate the current responses toward L-cys. The results of CV response of L-cys revealed the following findings: (1) PB-Chi/GCE was the least sensitive to L-cys, (2) Ag-PB-Chi/GCE exhibited higher current response than that of PB-Chi/GCE (1.2 times fold higher), and (3) Cu-Ag-PB-Chi/GCE owned a significant increase of sensitivity toward L-cys, as compared to that of PB-Chi (1.8 times fold increase) and Ag-PB-Chi/GCE (1.5 times fold increase). This improvement implied the contribution of synergetic effects of catalytic behavior of 500-Ag-Cu/PVP fibers in electrooxidation of L-cys. The sensing performance of Cu-Ag-PB-Chi/GCE was examined by amperometric test under optimized conditions. The Cu-Ag-PB-Chi/GCE showed two linear ranges over conentrations of 40-1800 and 1800-2500 µM with corresponding sensitivities of 0.1501 and 0.0707µA.µM-1cm-2, respectively, with the detection limit of 1.42 µM. According to interference tests, Cu-Ag-PB-Chi/GCE was selective toward L-cys and showed negligible response to sucrose, glucose, citric acid, oxalic acid, urea (concentration ratio L-cys to interferent= 1:1), uric acid, and EDTA (concentration ratio L-cys to interferent= 10:1).
The second objective of this thesis is to prepare L-cys sensor based on Cu/AuE. The Cu/AuE was developed by potentiostatic deposition of metallic Cu from a precursor solution onto AuE. The surface morphology and crystallinity of the Cu/AuE were studied by SEM and XRD, respectively. According to SEM observation, the homogeneous coverage of copper layer on AuE was obtained for longer deposition time (≥ 480 s). In addition, dendrites structure of copper can be produced when high overpotential (≤ -0.7 V) was applied. XRD pattern of Cu/AuE confirmed that copper was successfully electro-deposited on the surface without the presence of its corresponding oxide forms. For further assessments, AuE was electrodeposited at -0.4 V for 480 s from solution containing 0.005 M of CuSO4 and 0.3 M Na2SO4, concerning the highest amperometric response resulted from Cu/AuE farbricated under these parameters. The electrochemical characteristics of Cu/AuE were investigated using cyclic voltammetry tests. Based on CV results, the Cu/AuE displayed a prominent anodic peak ascribed for electrooxidation of L-cys, indicating greater electrooxidation activity toward L-cys than bare AuE. The amperometric test run under optimized conditions showed that the Cu/AuE had lowest detection limit of 0.21 µM and two linear ranges between 1-400 and 400-1800 µM with corresponding sensitivities of 1.0493 and 0.5090 µA.µM-1.cm-2, respectively. Additionally, the Cu/AuE also exhibited high specificity to L-cys, as minor influence from sucrose, glucose, citric acid, oxalic acid, urea, EDTA (concentration ratio L-cys to interferent= 1:1), and uric acid (concentration ratio L-cys to interferent= 40:1) to the L-cys signal.

1. Sharifi, E., A. Salimi, and E. Shams, DNA/nickel oxide nanoparticles/osmium(III)-complex modified electrode toward selective oxidation of l-cysteine and simultaneous detection of l-cysteine and homocysteine. Bioelectrochemistry, 2012. 86: p. 9-21.
2. Dong, Y. and J. Zheng, A nonenzymatic L-cysteine sensor based on SnO2-MWCNTs nanocomposites. Journal of Molecular Liquid, 2014. 196: p. 280-284.
3. Xu, F., F. Wang, D. Yang, Y. Gao, and H. Li, Electrochemical sensing platform for L-CySH based on nearly uniform Au nanoparticles decorated graphene nanosheets. Materials Science and Engineering C, 2014. 38: p. 292-298.
4. Pandey, P.C., A.K. Pandey, and D.S. Chauhan, Nanocomposite of Prussian blue based sensor for l-cysteine: Synergetic effect of nanostructured gold and palladium on electrocatalysis. Electrochimica Acta, 2012. 74: p. 23-31.
5. Pelletier, S. and C.A. Lucy, HPLC simultaneous analysis of thiols and disulfides: on-line reduction and indirect fluorescence detection without derivatization. Analyst, 2004. 129(8): p. 2004.
6. Lee, C.-J. and J. Yang, α-Cyclodextrin-modified infrared chemical sensor for selective determination of tyrosine in biological fluids. Analytical Biochemistry, 2006. 359(1): p. 124-131.
7. Zhao, C., J. Zhang, and J. Song, Determination of l-cysteine in amino acid mixture and human urine by flow-Injection analysis with a biamperometric detector. Analytical Biochemistry, 2001. 297(2): p. 170-176.
8. Chiesl, T.N., W.K. Chu, A.M. Stockton, X. Amashukeli, F. Grunthaner, and R.A. Mathies, Enhanced amine and amino acid analysis using pacific blue and the mars organic analyzer microchip capillary electrophoresis system. Analytical Chemistry, 2009. 81(7): p. 2537-2544.
9. Wang, X., C. Luo, L. Li, and H. Duan, Highly selective and sensitive electrochemical sensor for L-cysteine detection based on graphene oxide/multiwalled carbon nanotube/manganese dioxide/gold nanoparticles composite. Journal of Electroanalytical Chemistry, 2015. 757: p. 100-106.
10. Wu, L., J. Li, and H.-M. Zhang, One step fabrication of Au nanoparticles-Ni-Al layered double hydroxide composite film for the determination of L-Cysteine. Electroanalysis, 2015. 27: p. 1195-1201.
11. Bucur, M.P., B. Bucur, C.M. Radulescu, O.I. Covaci, and G.L. Radu, L-cysteine determination based on tyrosinase amperometric biosensors without interferences from thiolic compounds. Analytical Letters, 2010. 43(15): p. 2440-2455.
12. Santhiago, M. and I.C. Vieira, L-Cysteine determination in pharmaceutical formulations using a biosensor based on laccase from Aspergillus oryzae. Sensors and Actuators B, 2007. 128(1): p. 279-285.
13. Hassana, S.S.M., A.F. El-Baz, and H.S.M. Abd-Rabboh, A novel potentiometric biosensor for selective l-cysteine determination using l-cysteine-desulfhydrase producing Trichosporon jirovecii yeast cells coupled with sulfide electrode. Analytica Chimica Acta, 2007. 602: p. 108-113.
14. Harfield, J.C., C. Batchelor-McAuley, and R.G. Compton, Electrochemical determination of glutathione: a review. Analyst, 2012. 137: p. 2285-2296.
15. Sattarahmady, N. and H. Heli, An electrocatalytic transducer for l-cysteine detection based on cobalt hexacyanoferrate nanoparticles with a core-shell structure. Analytical Biochemistry, 2011. 409(1): p. 74-80.
16. Hallaj, R., A. Salimi, K. Akhtari, S. Soltanian, and H. Mamkhezri, Electrodeposition of guanine oxidation product onto zinc oxide nanoparticles: Application to nanomolar detection of l-cysteine. Sensors and Actuators B, 2009. 135(2): p. 632-641.
17. Bai, Y.-H., J.-J. Xu, and H.-Y. Chen, Selective sensing of cysteine on manganese dioxide nanowires and chitosan modified glassy carbon electrodes. Biosensors and Bioelectronics, 2009. 24: p. 2985-2990.
18. Zhou, M., J. Ding, L.-p. Guo, and Q.-k. Shang, Electrochemical behavior of l-cysteine and its detection at ordered mesoporous carbon-modified glassy carbon electrode. Analytical Chemistry, 2007. 79: p. 5328-5335.
19. Corrêa, C.C., S.A.V. Jannuzzi, M. Santhiago, R.A. Timm, A.L.B. Formiga, and L.T. Kubota, Modified electrode using multi-walled carbon nanotubes and ametallopolymer for amperometric detection of l-cysteine. Electrochimica Acta, 2013. 113: p. 332-339.
20. Wang, L., SimonTricard, P. Yue, J. Zhao, J. Fang, and W. Shen, Polypyrrole and graphene quantumdots @Prussian Blue hybrid film on graphite felt electrodes: Application for amperometric determination of L-cysteine. Biosensors andBioelectronics, 2016. 77: p. 1112-1118.
21. Xu, S., H. Li, L. Wang, Q. Yue, S. Sixiu, and J. Liu, One-pot synthesis of Ag@Cu yolk-shell nanostructures and their application as non-enzymatic glucose biosensors. CrystEngComm, 2014. 16(38): p. 9075-9082.
22. Ren, X., X. Meng, D. Chen, F. Tang, and J. Jiao, Using silver nanoparticle to enhance current response of biosensor. Biosensors and Bioelectronics, 2005. 21(3): p. 433-437.
23. Li, H., C.-Y. Guo, and C.-L. Xu, A highly sensitive non-enzymatic glucose sensor based on bimetallic Cu–Ag superstructures. Biosensors and Bioelectronics, 2015. 63: p. 339-346.
24. Lowinsohn, D., E.M. Richter, L. Angnes, and M. Bertotti, Disposable gold electrodes with reproducible area using recordable CDs and toner masks. Electroanalysis, 2005. 18(1): p. 89-94.
25. Granato, F., M. Scampicchio, A. Bianco, S. Mannino, C. Bertarelli, and G. Zerbia, Disposable electrospun electrodes based on conducting nanofibers. Electroanalysis, 2008. 20(12): p. 1374-1377.
26. Priano, G., G. Gonzalez, M. Gunther, and F. Battaglini, Disposable gold electrode array for simultaneous electrochemical studies. Electroanalysis, 2008. 20(1): p. 91-97.
27. Ge, S., M. Yan, J. Lu, M. Zhang, F. Yu, J. Yu, X. Song, and S. Yu, Electrochemical biosensor based on graphene oxide-Au nanoclusters composites for l-cysteine analysis. Biosensors and Bioelectronics, 2012. 31: p. 49-54.
28. Ruiz-Diaz, J.J.J., A.A.J. Torriero, E. Salinas, E.J. Marchevsky, M.I. Sanz, and J. Raba, Enzymatic rotating biosensor for cysteine and glutathione determination in a FIA system. Talanta, 2006. 68: p. 1343-1352.
29. Carvalho, R.C., A. Mandil, K.P. Prathish, A. Amine, and C.M.A. Brett, Carbon nanotube, carbon black and copper nanoparticle modified screen printed electrodes for amino acid determination. Electroanalysis, 2013. 25(4): p. 903-913.
30. Prasad, K.S., G. Muthuraman, and J.-M. Zen, Direct electrocatalytic oxxidation of cysteine and cystine based on nafion/lead oxide-manganese oxide combined catalyst. Electroanalysis, 2008. 20(11): p. 1167-1174.
31. Bakthavatsalam, R., S. Ghosh, R.K. Biswas, A. Saxena, A. Raja, M.O. Thotiyl, S. Wadhai, A.G. Banpurkarc, and J. Kundu, Solution chemistry-based nano-structuring of copper dendrites for efficient use in catalysis and superhydrophobic surfaces. RSC Advances, 2016. 6: p. 8416-8430.
32. Fei, S., J. Chen, S. Yao, G. Deng, D. He, and Y. Kuang, Electrochemical behavior of l-cysteine and its detection at carbon nanotube electrode modified with platinum. Analytical Biochemistry, 2005. 339(1): p. 29-35.
33. Silva, F.d.A.d.S., M.G.A. Silva, P.R. Lima, M.R. Meneghetti, L. Kubota, and M.O.F. Goulart, A very low potential electrochemical detection of L-cysteine based on a glassy carbon electrode modified with multi-walled carbon nanotubes/gold nanorods. Biosensors and Bioelectronics, 2013. 50: p. 202-209.
34. Amarnath, K., V. Amarnath, K. Amarnath, H.L. Valentine, and W.M. Valentine, A specific HPLC-UV method for the determination of cysteine and related aminothiols in biological samples. Talanta, 2003. 60: p. 1229-1238.
35. Wang, W., O. Rusin, X. Xu, K.K. Kim, J.O. Escobedo, S.O. Fakayode, K.A. Fletcher, M. Lowry, C.M. Schowalter, C.M. Lawrence, F.R. Fronczek, I.M. Warner, and R.M. Strongin, Detection of homocysteine and cysteine. Journal of American Chemical Society, 2005. 127: p. 15949-15958.
36. Prasad, B.B. and R. Singh, A new micro-contact imprinted l-cysteine sensor based on sol-gel decorated graphite/multiwalled carbon nanotubes/goldnanoparticles composite modified sandpaper electrode. Sensors and Actuators B, 2015. 212: p. 155-164.
37. Ahmad, M., C. Pan, and J. Zhu, Electrochemical determination of L-Cysteine by an elbow shaped, Sb-doped ZnO nanowire-modified electrode. Journal of Materials Chemistry, 2010. 20: p. 7169-7174.
38. Wu, W., G. Goldstein, C. Adams, R.H. Matthews, and N. Ercal, Separation and quantification of N-acetyl-l-cysteine and N-acetyl-cysteine-amide by HPLC with fluorescence detection. Biomedical Chromatography, 2006. 20(5): p. 415-422.
39. Jung, H.S., J.H. Han, T. Pradhan, S. Kim, S.W. Lee, J.L. Sessler, T.W. Kim, C. Kang, and J.S. Kim, A cysteine-selective fluorescent probe for the cellular detection of cysteine. Biomaterials, 2012. 33: p. 945-953.
40. Li, H., J. Fan, J. Wang, M. Tian, J. Du, S. Sun, P. Sun, and X. Peng, A fluorescent chemodosimeter specific for cysteine: effective discrimination of cysteine from homocysteine. Chemical Communications, 2009(39): p. 5904-5906.
41. Carlucci, F. and A. Tabucchi, Capillary electrophoresis in the evaluation of aminothiols in body fluids. Journal of Chromatography B, 2009. 877(28): p. 3347-3357.
42. Jellum, E., A.K. Thorsrud, and E. Time, Capillary electrophoresis for diagnosis and studies of human disease, particularly metabolic disorders. 1991. 559(1-2): p. 455-465.
43. Deáková, Z., Z. Ďuračková, D.W. Armstrong, and J. Lehotay, Two-dimensional high performance liquid chromatography for determination of homocysteine, methionine and cysteine enantiomers in human serum. Journal of Chromatography A, 2015. 1408: p. 118-124.
44. Cevasco, G., A.M. Pi˛atek, C. Scapolla, and S. Thea, An improved method for simultaneous analysis of aminothiols in human plasma by high-performance liquid chromatography with fluorescence detection. Journal of Chromatography A, 2010. 1217: p. 2158-2162.
45. Liu, J., Y.-Q. Sun, Y. Huo, H. Zhang, L. Wang, P. Zhang, Dan Song, Y. Shi, and W. Guo, Simultaneous fluorescence sensing of cys and GSH from different emission channels. Journal of American Chemical Society, 2013. 136: p. 574-577.
46. Yuan, X., Y. Tay, X. Dou, Z. Luo, D.T. Leong, and J. Xie, Glutathione-protected silver nanoclusters as cysteine-selective fluorometric and colorimetric probe. Analytical Chemistry, 2013. 85: p. 1913-1919.
47. Du, J., Y. Li, and J. Lu, Investigation on the chemiluminescence reaction of luminol-H2O2-S2-/R-SH system. Analytica Chimica Acta, 2001. 448(1-2): p. 79-83.
48. Kamidate, T., T. Tani, and H. Watanabe, Resolution of amino thiols in time-resolved luminol chemiluminescence catalyzed by peroxidases. Analytical Sciences, 1998. 14(14): p. 725-729.
49. Viñas, P., I.L. Garcia, and J.A.M. Gil, Determination of thiol-containing drugs by chemiluminescence—flow injection analysis. Journal of Pharmaceutical and Biomedical Analysis, 1993. 11(1): p. 15-20.
50. Yang, N., H. Song, X. Wan, X. Fan, Y. Su, and Y. Lv, A metal (Co)–organic framework-based chemiluminescence system for selective detection of L-cysteine. Analyst, 2015. 140: p. 2656-2663.
51. Ivanov, A.V., E.D. Virus, B.P. Luzyanin, and A.A. Kubatiev, Capillary electrophoresis coupled with 1,1'-thiocarbonyldiimidazole derivatization for the rapid detection of total homocysteine and cysteine in human plasma. Journal of Chromatography B, 2015. 1004: p. 30-36.
52. Salimi, A. and R. Hallaj, Catalytic oxidation of thiols at preheated glassy carbon electrode modified with abrasive immobilization of multiwall carbon nanotubes: applications to amperometric detection of thiocytosine, l-cysteine and glutathione. Talanta, 2005. 66: p. 967-975.
53. Wang, Y., W. Peng, L. Liu, F. Gao, and M. Li, The electrochemical determination of l-cysteine at a Ce-doped Mg–Al layered double hydroxide modified glassy carbon electrode. Electrochimica Acta, 2012. 70: p. 193-198.
54. Wang, A., L. Zhang, S. Zhang, and Y. Fang, Determination of thiols following their separation by CZE with amperometric detection at a carbon electrode. Journal of Pharmaceutical and Biomedical Analysis, 2000. 23: p. 429-436.
55. Hosseini, H., H. Ahmar, A. Dehghani, AkbarBagheri, A. Tadjarodi, and A.R. Fakhari, A novel electrochemical sensor based on metal-organic framework for electro-catalytic oxidation of L-cysteine. Biosensors and Bioelectronics, 2013. 42: p. 426-429.
56. Spãtaru, N., B.V. Sarada, E. Popa, D.A. Tryk, and A. Fujishima, Voltammetric determination of l-cysteine at conductive diamond electrodes. Analytical Chemistry, 2001. 73(3): p. 514-519.
57. Zen, J.-M., A.S. Kumar, and J.-C. Chen, Electrocatalytic oxidation and sensitive detection of cysteine on a lead ruthenate pyrochlore modified electrode. Analytical Chemistry, 2001. 73(6): p. 1169-1175.
58. Mincheva, R., O. Stoilova, H. Penchev, T. Ruskov, I. Spirov, N. Manolovaa, and I. Rashkov, Synthesis of polymer-stabilized magnetic nanoparticles and fabrication of nanocomposite fibers thereof using electrospinning. European Polymer Journal, 2008. 44(3): p. 615-627.
59. Solanki, P.R., A. Kaushik, V.V. Agrawal, and B.D. Malhotra, Nanostructured metal oxide-based biosensors. NPG Asia Materials, 2011. 3(1): p. 17-24.
60. Grieshaber, D., R. MacKenzie, J. Voros, and E. Reimhult, Electrochemical biosensors - sensor principles and architectures. Sensors, 2008. 8: p. 1400-1458.
61. Tîlmaciu, C.-M. and M.C. Morris, Carbon nanotube biosensors. Frotiers in Chemistry, 2015. 35(59): p. 1-29.
62. Ricci, F. and G. Palleschi, Sensor and biosensor preparation, optimisation and applications of Prussian Blue modified electrodes. Biosensors and Bioelectronics, 2005. 21: p. 389-407.
63. Liu, X., L. Luo, Y. Ding, Z. Kang, and D. Ye, Simultaneous determination of L-cysteine and L-tyrosine using Au-nanoparticles/poly-eriochrome black T film modified glassy carbon electrode. Bioelectrochemistry, 2012. 86: p. 38-45.
64. Zare, H.R., F. Jahangiri-Dehaghani, Z. Shekari, and A. Benvidi, Electrocatalytic simultaneous determination of ascorbic acid, uric acid and l-cysteine in real samples using quercetin silver nanoparticles–graphene nanosheets modified glassy carbon electrode. Applied Surface Science, 2016. 375: p. 169-178.
65. Salimi, A. and M. Roushani, Electrocatalytic oxidation of sulfur containing amino acids at renewable Ni‐powder doped carbon ceramic electrode: Application to amperometric detection l‐cystine, l‐cysteine and l‐methionine. Electroanalysis, 2006. 18(21): p. 2129-2136.
66. Dong, Y., L. Pei, X. Chu, W. Zhang, and Q. Zhang, Electrochemical behavior of cysteine at a CuGeO3 nanowires modified glassy carbon electrode. Electrochimica Acta 55 (2010) 5135–5141, 2010. 55: p. 5135-5141.
67. Murugavelu, M. and B. Karthikeyan, Study of Ag-Pd bimetallic nanoparticles modified glassy carbon electrode for detection of l-cysteine. Superlattices and Microstructures, 2014. 75: p. 916-926.
68. Majidi, M.R., K. Asadpour-Zeynali, and B. Hafezi, Sensing L-cysteine in urine using a pencil graphite electrode modified with a copper hexacyanoferrate nanostructure. Microchimica Acta, 2010. 169: p. 283-288.
69. Du, D., M. Wang, Y. Qin, and Y. Lin, One-step electrochemical deposition of Prussian Blue–multiwalled carbon nanotube nanocomposite thin-film: preparation, characterization and evaluation for H2O2 sensing. Journal of Materials Chemistry, 2010. 20: p. 1532-1537.
70. Ricci, F., F. Arduini, A. Amine, D. Moscone, and G. Palleschi, Characterisation of Prussian blue modified screen-printed electrodes for thiol detection. Journal of Electroanalytical Chemistry, 2004. 563: p. 229-237.
71. Itaya, K., I. Uchida, and V.D. Neff, Electrochemistry of polynuclear transition metal cyanides: Prussian Blue and its analogues. Accounts of Chemical Research, 1986. 19: p. 162-168.
72. Ghaderi, S. and M.A. Mehrgardi, Prussian blue-modified nanoporous gold film electrode for amperometric determination of hydrogen peroxide. Bioelectrochemistry, 2014. 98: p. 64-69.
73. Petkova, G.A., . Záruba, P. Žvátora, and V. Král, Gold and silver nanoparticles for biomolecule immobilization and enzymatic catalysis. Nanoscale Research Letters, 2012. 7: p. 287.
74. Luo, X., A. Morrin, A.J. Killard, and M.R. Smyth, Application of nanoparticles in electrochemical sensors and biosensors. Electroanalysis, 2006. 18(4): p. 319-326.
75. Tee, S.Y., C.P. Teng, and E. Ye, Metal nanostructures for non-enzymatic glucose sensing. Materials Science and Engineering C, 2016.
76. Zen, J.-M., C.-T. Hsu, A.S. Kumar, H.-J. Lyuu, and K.-Y. Lin, Amino acid analysis using disposable copper nanoparticle plated electrodes. Analyst, 2004. 129: p. 841-845.
77. Luo, P., F. Zhang, and R.P. Baldwin, Constant-potential amperometric detection of underivatized amino acids and peptides at a copper electrode. Analytical Chemistry, 1991. 63: p. 1702-1707.
78. Mondin, G., M.R. Lohe, F.M. Wisser, J. Grothe, N. Mohamed-Noriega, A. Leifert, S. Dörfler, A. Bachmatiuk, M.H. Rümmeli, and S. Kaskel, Electroless copper deposition on (3-mercaptopropyl)triethoxysilane-coated silica and alumina nanoparticles. Electrochimica Acta, 2013. 114: p. 521-526.
79. Zabetakis, D. and W.J. Dressick, Selective electroless metallization of patterned polymeric films for lithography applications. ACS Applied Materials and Interfaces, 2009. 1(1): p. 4-25.
80. Djokic, S.S., Electroless Deposition of Metals and Alloys, in Modern Aspects of Electrochemistry, B.E. Conway and R.E. White, Editors. 2002, Springer US: New York. p. 51-133.
81. Kim, E., N.S. Arul, L. Yang, and J.I. Han, Electroless plating of copper nanoparticles on PET fiber for non-enzymatic electrochemical detection of H2O2. RSC Advances, 2015. 5: p. 76729-76732.
82. Cheng, D.H., W.Y. Xu, Z.Y. Zhang, and Z.H. Yiao, Electroless copper plating using hypophosphite as reducing agent. Metal Finishing, 1997. 95(1): p. 36-37.
83. Wang, P.-C., C.-P. Chang, M.-J. Youh, Y.-M. Liu, C.-M. Chu, and M.-D. Ger, The preparation of pH-sensitive Pd catalyst ink for selective electroless deposition of copper on a flexible PET substrate. Journal of the Taiwan Institute of Chemical Engineers, 2016. 60: p. 555-563.
84. Prissanaroon, W., N. Brack, P.J. Pigram, P. Hale, P. Kappen, and J. Liesegang, Fabrication of patterned polypyrrole on fluoropolymers for pH sensing applications. Synthetic Metals, 2005. 154: p. 105-108.
85. Rahman, H.H.A., A.H.E. Moustafa, and S.M.K.A. Magid, High rate copper electrodeposition in the presence of inorganic salts. International Journal of Electrochemcal Science 2012. 7: p. 6959-6975.
86. Yokoi, M., Copper electrodeposition for nanofabrication of electronics devices, in Nanostructure Science and Technology, K. Kondo, R.N. Akolkar, D.P. Barkey, and M. Yokoi, Editors. 2014, Springer US: New York. p. 3-10.
87. Brett, C.M.A. and A.M.O. Brett, Electrochemistry in industry, in Electrochemistry, principles, methods, and applications, J. Heinze, Editor. 1994, Oxford University Press: Oxford. p. 343.
88. Deng, Y., H. Ling, X. Feng, T. Hang, and M. Li, Electrodeposition and characterization of copper nanocone structures. CrystEngComm, 2015. 17: p. 868-876.
89. Zhou, X.J., A.J. Harmer, N.F. Heinig, and K.T. Leung, Parametric study on electrochemical deposition of copper nanoparticles on an ultrathin polypyrrole film deposited on a gold film electrode. Langmuir, 2004. 20: p. 5109-5113.
90. Ghodbane, O., L. Roué, and D. Bélanger, Copper electrodeposition on pyrolytic graphite electrodes: Effect of the copper salt on the electrodeposition process. Electrochimica Acta, 2007. 52(19): p. 5843-5855.
91. Kang, X.H., Z.B. Mai, X.Y. Zou, P.X. Cai, and J.Y. Mo, A sensitive nonenzymatic glucose sensor in alkaline media with a copper nanocluster/multiwall carbon nanotube-modified glassy carbon electrode. Analytical Biochemistry, 2007. 363: p. 143-150.
92. Yang, J., W.-D. Zhang, and S. Gunasekaran, An amperometric non-enzymatic glucose sensor by electrodepositing copper nanocubes onto vertically well-aligned multi-walled carbon nanotube arrays. Biosensors and Bioelectronics, 2010. 26(1): p. 279-284.
93. Benuzzi, M.L.S., S.V. Pereira, J. Raba, and G.A. Messina, Screening for cystic fibrosis via a magnetic and microfluidic immunoassay format with electrochemical detection using a copper nanoparticle-modified gold electrode. Microchimica Acta, 2016. 183: p. 397-405.
94. Ondarçuhu, T. and C. Joachim, Drawing a single nanofibre over hundreds of microns. Europhysics Letters, 1998. 42(2): p. 215-220.
95. Martin, C.R., Membrane-based synthesis of nanomaterials. Chemistry of Materials, 1996. 8(8): p. 1739-1746.
96. Ma, P.X. and R. Zhang, Synthetic nano-scale fibrous extracellular matrix. Journal of Biomedical Materials Research, 1999. 46(1): p. 60-72.
97. Whitesides, G.M. and B. Grzybowski, Self-assembly at all scales. Science, 2002. 295: p. 2418-2421.
98. Demira, M.M., I. Yilgorb, E. Yilgorb, and B. Erman, Electrospinning of polyurethane fibers. Polymer, 2002. 43(11): p. 3303-3309.
99. Huang, Z.-M., Y.-Z. Zhang, M. Kotakic, and S. Ramakrishna, A review on polymer nanofibers by electrospinning and their applications in nanocomposites. Composites Science and Technology, 2003. 63: p. 2223-2253.
100. Luo, C.J., S.D. Stoyanov, E. Stride, E. Pelan, and M. Edirisinghe, Electrospinning versus fibre production methods: from specifics to technological convergence. Chemical Society Review, 2012. 41: p. 4708-4735.
101. Reneker, D.H. and I. Chun, Nanometre diameter fibres of polymer, produced by electrospinning. Nanotechnology, 1996. 7(3): p. 216-223.
102. Agarwal, S., A. Greiner, and J.H. Wendorff, Functional materials by electrospinning of polymers. Progress in Polymer Science, 2013. 38: p. 963-991.
103. Lombardi, M., P. Palmero, M. Sangermano, and A. Varesano, Electrospun polyamide-6 membranes containing titanium dioxide as photocatalyst. Polymer International, 2010. 60(2): p. 234-239.
104. Lim, J.-M., G.-R. Yi, J.H. Moon, C.-J. Heo, and S.-M. Yang, Superhydrophobic films of electrospun fibers with multiple-scale surface morphology. Langmuir, 2007. 23(15): p. 7981-7989.
105. Yi, L., X. Meng, X. Tian, W. Zhou, and R. Chen, Wettability of electrospun films of microphase-separated block copolymers with 3,3,3 trifluoropropyl substituted siloxane segments. The Journal of Physical Chemistry C, 2014. 118(46): p. 26671-26682.
106. Srikar, R., A.L. Yarin, C.M. Megaridis, A.V. Bazilevsky, and E. Kelley, Desorption-limited mechanism of release from polymer nanofibers. Langmuir, 2008. 24(3): p. 965-974.
107. Sill, T.J. and H.A.v. Recum, Electrospinning: Applications in drug delivery and tissue engineering. Biomaterials, 2008. 29(13): p. 1989-2006.
108. Wu, H., L. Hu, M.W. Rowell, D. Kong, J.J. Cha, J.R. McDonough, J. Zhu, Y. Yang, M.D. McGehee, and Y. Cui, Electrospun metal nanofiber webs as high-performance transparent electrode. Nano Letters, 2010. 10(10): p. 4242-4248.
109. Sen, R., B. Zhao, D. Perea, M.E. Itkis, H. Hu, J. Love, E. Bekyarova, and R.C. Haddon, Preparation of single-walled carbon nanotube reinforced polystyrene and polyurethane nanofibers and membranes by electrospinning. Nano Letters, 2004. 4(3): p. 459-464.
110. Ramakrishna, S., R. Jose, P.S. Archana, A.S. Nair, R. Balamurugan, J. Venugopal, and W.E. Teo, Science and engineering of electrospun nanofibers for advances in clean energy, water filtration, and regenerative medicine. Journal of Materials Science, 2010. 45(23): p. 6283-6312.
111. Kumar, P.S., J. Sundaramurthy, S. Sundarrajan, V.J. Babu, G. Singh, S.I. Allakhverdiev, and S. Ramakrishna, Hierarchical electrospun nanofibers for energy harvesting, production and environmental remediation. Energy & Environmental Science, 2014. 7: p. 3192-3222.
112. Bhardwaj, N. and S.C. Kundu, Electrospinning: A fascinating fiber fabrication technique. Biotechnology Advances, 2010. 28(3): p. 325-347.
113. Baji, A., Y.-W. Mai, S.-C. Wong, M. Abtahi, and P. Chen, Electrospinning of polymer nanofibers: Effects on oriented morphology, structures and tensile properties. Composites Science and Technology, 2010. 70: p. 703-718.
114. Li, D. and Y. Xia, Electrospinning of nanofibers: Reinventing the wheel? Advanced Materials, 2004. 16(14): p. 1151-1170.
115. Reneker, D.H., A.L. Yarin, H. Fong, and K. Sureeporn, Bending instability of electrically charged liquid jets of polymer solution in electrospinning. Journal of Applied Physics, 2000. 87: p. 4531-4547.
116. Shin, Y.M., M.M. Hohman, M.P. Brenner, and G.C. Rutledge, Experimental characterization of electrospinning: the electrically forced jet and instabilities. Polymer, 2001. 42: p. 9955-9967.
117. Zuo, W.W., M.F. Zhu, W. Yang, H. Yu, Y.M. Chen, and Y. Zhang, Experimental study on relationship between jet instability and formation of beaded fibers during electrospinning. Polymer Engineering & Science, 2005. 45: p. 704-709.
118. Zhang, C., Q. Yang, N. Zhan, L. Sun, H. Wang, Y. Song, and Y. Li, Silver nanoparticles grown on the surface of PAN nanofiber: Preparation, characterization and catalytic performance. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2010. 362: p. 58-64.
119. Bao, Y., C. Lai, Z. Zhu, H. Fong, and C. Jiang, SERS-active silver nanoparticles on electrospun nanofibers facilitated via oxygen plasma etching. RSC Advances, 2013. 3: p. 8998-9004.
120. Zhang, L., X. Gong, Y. Bao, Y. Zhao, M. Xi, C. Jiang, and H. Fong, Electrospun nanofibrous membranes surface-decorated with silver nanoparticles as flexible and active/sensitive substrates for surface-enhanced raman scattering. Langmuir, 2012. 28(40): p. 14433-1440.
121. Wang, J., H.-B. Yao, D. He, C.-L. Zhang, and S.-H. Yu, Facile fabrication of gold nanoparticles-poly(vinyl alcohol) electrospun water-stable nanofibrous mats: efficient substrate materials for biosensors. ACS Applied Materials and Interfaces, 2012. 4(4): p. 1963-1971.
122. Zhu, H., M. Du, M. Zhang, P. Wang, S. Bao, L. Wang, Y. Fu, and J. Yao, Facile fabrication of AgNPs/(PVA/PEI) nanofibers: High electrochemical efficiency and durability for biosensors. Biosensors and Bioelectronics, 2013. 49: p. 210-215.
123. Ouyang, Z., J. Li, J. Wang, Q. Li, T. Ni, X. Zhang, H. Wang, Q. Li, Z. Su, and G. Wei, Fabrication, characterization and sensor application of electrospun polyurethane nanofibers filled with carbon nanotubes and silver nanoparticles. Journal of Materials Chemistry B, 2013. 1: p. 2415-2424.
124. Mondal, K., M.A. Ali, V.V. Agrawal, B.D. Malhotra, and A. Sharma, Highly sensitive biofunctionalized mesoporous electrospun TiO2 nanofiber based interface for biosensing. ACS Applied Materials and Interfaces, 2014. 6: p. 2516-2527.
125. Huang, Y., Y.-E. Miao, S. Ji, W.W. Tjiu, and T. Liu, Electrospun carbon nanofibers decorated with Ag-Pt bimetallic nanoparticles for selective detection of dopamine. ACS Applied Materials and Interfaces, 2014. 6(15): p. 12449-12456.
126. Fu, J., D. Li, G. Li, F. Huang, and Q. Wei, Carboxymethyl cellulose assisted immobilization of silver nanoparticles onto cellulose nanofibers for the detection of catechol. Journal of Electroanalytical Chemistry, 2015. 738: p. 92-99.
127. Bao, S., M. Du, M. Zhang, H. Zhu, P. Wang, T. Yang, and M. Zou, Facile fabrication of polyaniline nanotubes/gold hybrid nanostructures as substrate materials for biosensors. Chemical Engineering Journal, 2014. 258: p. 281-289.
128. Zhu, H., M. Zhang, S. Cai, Y. Cai, P. Wang, S. Bao, M. Zou, and M. Du, In situ growth of Rh nanoparticles with controlled sizes and dispersions on the cross-linked PVA–PEI nanofibers and their electrocatalytic properties towards H2O2. RSC Advances, 2014. 4: p. 794-804.
129. Mabbott, G.A., An introduction to cyclic voltammetry. Journal of Chemical Education, 1983. 60(9): p. 697-702.
130. Roussel, T.J., D.J. Jackson, R.P. Baldwin, and R.S. Keynton, Amperometric techniques, in Encyclopedia of microfluidics and nanofluidics, D. Li, Editor. 2008, Springer US: New York. p. 39-47.
131. Castillo-Ortega, M.M., J. Romero-García, F. Rodríguez, A. Nájera-Luna, and P.J. Herrera-Franco, Fibrous membranes of cellulose acetate and poly(vinyl pyrrolidone) by electrospinning method: Preparation and characterization. Journal of Applied Polymer Science, 2010. 116(4): p. 1873-1878.
132. Xiang, H., Y. Long, X. Yu, X. Zhang, N. Zhao, and J. Xu, A novel and facile method to prepare porous hollow CuO and Cu nanofibers based on electrospinning. CrystEngComm, 2011. 13: p. 4856-4860.
133. Bai, J., Y. Li, C. Zhang, X. Liang, and Q. Yang, Preparing AgBr nanoparticles in poly(vinyl pyrrolidone) (PVP) nanofibers. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2008. 329(3): p. 165-168.
134. Washio, I., Y. Xiong, Y. Yin, and Y. Xia, Reduction by the end groups of poly(vinyl pyrrolidone): A new and versatile route to the kinetically controlled synthesis of Ag triangular nanoplates. Advanced Materials, 2006. 18: p. 1745-1749.
135. Wu, S., F. Li, H. Wang, L. Fu, B. Zhang, and G. Li, Effects of poly (vinyl alcohol) (PVA) content on preparation of novel thiol-functionalized mesoporous PVA/SiO2 composite nanofiber membranes and their application for adsorption of heavy metal ions from aqueous solution. Polymer, 2010. 51(26): p. 6203-6211.
136. Wang, Y., Y. Zhou, W. Wang, and Z. Chen, Sustained deposition of silver on copper surface from choline chloride aqueous solution. Journal of The Electrochemical Society, 2013. 160(3): p. D119-D123.
137. Butovsky, E., I. Perelshtein, and A. Gedanken, Air stable core–shell multilayer metallic nanoparticles synthesized RAPET: fabrication, characterization and suggested applications. Journal of Materials Chemistry, 2012. 22: p. 15025-15030.
138. O'Halloran, M.P., M. Pravda, and G.G. Guilbault, Prussian Blue bulk modified screen-printed electrodes for H2O2 detection and for biosensors. Talanta, 2001. 55(3): p. 605-611.
139. Ensafi, A.A. and S. Behyan, Sensing of l-cysteine at glassy carbon electrode using Nile blue A as a mediator. Sensors and Actuators B, 2007. 122: p. 282-288.
140. Silva, C.d.C.C.e., M.C. Breitkreitz, M. Santhiago, C.C. Corrêa, and L.T. Kubota, Construction of a new functional platform by grafting poly(4-vinylpyridine) in multi-walled carbon nanotubes for complexing copper ions aiming the amperometric detection of l-cysteine. Electrochimica Acta, 2012. 71: p. 150-158.
141. Lee, M.-Y., S.-J. Ding, C.-C. Wu, J. Peng, C.-T. Jiang, and C.-C. Chou, Fabrication of nanostructured copper phosphate electrodes for the detection of α-amino acids. Sensors and Actuators B, 2015. 206: p. 584-591.
142. Lee, M.-Y., J. Peng, and C.-C. Wu, Geometric effect of copper nanoparticles electrodeposited on screen-printed carbon electrodes on the detection of a-, b- and g-amino acids. Sensors and Actuators B: Chemical, 2013. 186: p. 270-277.
143. Thota, R. and V. Ganesh, Simple and facile preparation of silver–polydopamine (Ag–PDA) core–shell nanoparticles for selective electrochemical detection of cysteine. RSC Advances, 2016. 6: p. 49578-49587.
144. Cumba, L.R., U.d.O. Bicalho, and D.R.d. Carmo, Preparation and voltammetric studies of titanium (IV) phosphate modified with silver hexacyanoferrate to a voltammetric determination of l-cysteine. International Journal of Electrochemcal Science, 2012. 7: p. 4465-4478.
145. Majidi, M.R., K. Asadpour-Zeynali, and B. Hafezi, Reaction and nucleation mechanisms of copper electrodeposition on disposable pencil graphite electrode. Electrochimica Acta, 2009. 54(3): p. 1119-1126.
146. Qiu, R., H.G. Cha, H.B. Noh, Y.B. Shim, X.L. Zhang, R. Qiao, D. Zhang, Y.I. Kim, U. Pal, and Y.S. Kang, Preparation of dendritic copper nanostructures and their characterization for electroreduction. Journal of Physical Chemistry C, 2009. 113: p. 15891-15896.
147. Nikolić, N.D., K.I. Popov, L.J. Pavlović, and M.G. Pavlović, Morphologies of copper deposits obtained by the electrodeposition at high overpotentials. Surface and Coatings Technology, 2006. 201(3-4): p. 560-566.
148. Wang, A.-J., S.-F. Qin, D.-L. Zhou, L.-Y. Cai, J.-R. Chen, and J.-J. Feng, Caffeine assisted one-step synthesis of flower-like gold nanochains and their catalytic behaviors. RSC Advances, 2013. 3: p. 14766-14773.
149. Wu, W.-Q., H.-S. Rao, Y.-F. Xu, Y.-F. Wang, C.-Y. Su, and D.-B. Kuang, Hierarchical oriented anatase TiO2 nanostructure arrays on flexible substrate for efficient dye-sensitized solar cells. Scientific Reports, 2013. 3(1892): p. 1-7.
150. Ensafi, A.A., M.M. Abarghoui, and B. Rezaei, A new non-enzymatic glucose sensor based on copper/porous silicon nanocomposite. Electrochimica Acta, 2014. 123: p. 219-226.
151. Jia, D., Q. Ren, L. Sheng, F. Li, G. Xie, and Y. Miao, Preparation and characterization of multifunctional polypyrrole–Au coated NiO nanocomposites and study of their electrocatalysis toward several important bio-thiols. Sensors and Actuators B, 2011. 160(1): p. 168-173.
152. Luo, X., A.J. Killard, A. Morrin, and M.R. Smyth, Enhancement of a conducting polymer-based biosensor using carbon nanotube-doped polyaniline. Analytica Chimica Acta, 2006. 575(1): p. 39-44.
153. Özkan, Y., E. Özkan, and B. Şimşek, Plasma total homocysteine and cysteine levels as cardiovascular risk factors in coronary heart disease. International Journal of Cardiology, 2002. 82(3): p. 269-277.
154. Kannan, P. and A. John, Ultrasensitive detection of l-cysteine using gold–5-amino-2-mercapto-1,3,4-thiadiazole core–shell nanoparticles film modified electrode. Biosensors and Bioelectronics, 2011. 30: p. 276-281.