何國川臺灣大學：化學工程學研究所吳政達Wu, Cheng-TarCheng-TarWu2007-11-262018-06-282007-11-262018-06-282006http://ntur.lib.ntu.edu.tw//handle/246246/52374本研究中主要分為四大部份，首先我們以二氧化鈦（TiO2）為拓印基材，在目標分子（template）—尼古丁（nicotine, NIC）的存在下，使之均勻混，將尼古丁分子模版（molecularly imprinted polymer, MIP）製備於銦錫氧化物（indium tin oxide, ITO）導電玻璃上，再經由高溫燒結以固定TiO2並去除包覆於TiO2內之尼古丁而形成一尼古丁分子模版修飾電極（ITO/TiO2[NIC]），為增加修飾電極之靈敏度，再將3,4-ethylenedioxythiophene (EDOT)以電聚合法鍍於ITO/TiO2[NIC]之上，形成一具有良好導電度之尼古丁分子模版修飾電極（ITO/TiO2[NIC]/PEDOT），並以PEDOT薄膜催化尼古丁之能力，以定電位的方式（chronoamperometry）來感測尼古丁。而ITO/TiO2[NIC]/PEDOT電極之線性感測範圍為0~5 mM，靈敏度為31.4 μA/ mM•cm2，感測下限為11.1 μM（S/N=3），分子模版之拓印效率為1.24。此外，本研究更利用掃瞄式電化學顯微鏡（scanning electrochemical microscopy, SECM）以白金探針為工作電極，利用赤血鹽與黃血鹽之氧化還原對來判別分子模版修飾電極之表面形態。 第二部分之研究導入微機電（micro-electro-mechanical-system, MEMS）製程，製備三極式微電極，除工作電極之基材與參考電極改為白金與Ag/AgCl外，尼古丁分子模版修飾電極之製備方式與第一部分所提及相同。此外，我們同樣以定電位法感測尼古丁，線性感測範圍為0~5 mM，靈敏度為28.32 μA/ mM•cm2，感測下限為5.19 μM（S/N=3），分子模版之拓印效率為7.54。 第三部分之研究以苯胺aniline (AN)作為單體、兒茶素（(+)-catechin, (+)-C）為模版，以電聚合方式包覆分子模版於導電玻璃ITO上作為分子模版修飾電極（ITO/PAN[(+)-C]），並以定電位法感測兒茶素，線性感測範圍為0~50 μM，靈敏度為45.9 μA/ mM•cm2，感測下限為5 μM（S/N=3），而分子模版之拓印效率為1.46。 最後，將利用分子模版之技術分別以D與L-酪胺酸（tyrosine, Tyr）作為模版，拓印於氧化鋁（Al2O3）基材內，並使其鍍於氟錫氧化物（fluorine tin oxide, FTO）導電玻璃上，分別製備成FTO/Al2O3[D-Tyr]與FTO/Al2O3[L-Tyr]兩分子模版修飾電極，而後，同第一部分所提，將導電高分子PEDOT鍍於修飾電極上以增加感測器之靈敏度，FTO/Al2O3[D-Tyr]與FTO/Al2O3[L-Tyr]。對於L與D-酪胺酸辨識之實驗，我們利用具有選擇性質之分子模版孔洞利用循環伏安法（cyclic voltammetry, CV）來作D與L-酪胺酸之辨識。對於FTO/Al2O3[D-Tyr] /PEDOT與FTO/Al2O3[L-Tyr] /PEDOT兩模版修飾電極對其模版之光學選擇率（enatioselectivity, E.S.）分別為1.79與1.42。此外，我們更藉由SECM所作模版之吸附實驗來印證模版與其相對應電極間之吸附狀況。In the first part of this study, amperometric detection of nicotine (NIC) was carried out on a titanium dioxide (TiO2)/poly(3,4-ethylenedioxythiophene) (PEDOT) modified electrode by molecularly imprinted technique. The sensing material was prepared by coating a mixture of TiO2 colloid and the analyte, NIC, on a planar indium tin oxide electrode (ITO) followed by sintering. In order to improve the conductivity of the substrate, PEDOT was coated on the sintered electrode (ITO/TiO2[NIC]) by in-situ electrochemical polymerization of the EDOT monomer. Finally the NIC imprinted TiO2 electrode (ITO/TiO2[NIC]/PEDOT) was obtained. The linear detection range (LDR) for the NIC oxidation on the ITO/TiO2[NIC]/PEDOT electrode was between 0 to 5 mM, with a sensitivity, limit of detection (LOD), and imprinting efficiency (I.E.) of 31.35 μA/mM•cm2, 11.1 μM (S/N = 3) and 1.24 respectively. Moreover, scanning electrochemical microscopy (SECM) was employed to distinguish the surface morphology of the imprinted and the non-imprinted electrode using Fe(CN)63-/ Fe(CN)64- as a redox probe on a platinum tip. In the second part, a micro-electro-mechanical-system (MEMS) technology was employed to fabricate an on-chip three-electrode system. NIC was also electrochemically detected on a modified microelectrode made by molecular imprinting technique. The fabrication method of NIC imprinted electrode was similar to the first part, except that the working (ITO) and reference (Ag/AgCl/sat’d KCl) electrodes were replaced with Pt bar and Ag/AgCl, respectively. The NIC imprinted electrode was denoted as Pt/TiO2[NIC]/PEDOT. The LDR for NIC oxidation on the microelectrode was up to 5 mM, with a sensitivity, LOD and I.E. of 28.32 μA/mM•cm2, 5.19 μM, and 7.54 respectively. Furthermore, the SECM was also employed to distinguish the surface morphologies of the unmodified bar Pt and the Pt/TiO2[NIC]/PEDOT microelectrode by using Fe(CN)63-/ Fe(CN)64- as the redox couple. In the third part, (+)-catechin, abbreviated as (+)-C, was incorporated into polyaniline (PAN) thin film by acid protection mechanism which avoids the oxidation of (+)-C. The modified electrode was prepared by electropolymerizing (+)-C with aniline on an ITO electrode to form a (+)-C imprinted PAN modified electrode. After the template was extracted, a (+)-C MIP modified electrode (ITO/PAN/[(+)-C]) was obtained. Amperometric method was employed to detect (+)-C with the concentration varying from 0 to 150 μM. A LDR was obtained, which showed the relationship between the net steady-state current and the (+)-C concentration ranging from 0 to 50 μM at the ITO/PAN/[(+)-C] electrode. A LOD of 5 μM along with a sensitivity of 45.9 μA/mM∙cm2 was obtained for the ITO/PAN[(+)-C] electrode. In the last part, the recognition electrode was prepared by mixing either D or L-tyrosine (Tyr) with Al2O3 colloid, followed by the deposition onto a conducting fluorine tin oxide (FTO, sheet resistivity of 15 Ω/sq.) electrode by a glass rod to form both FTO/Al2O3[D-Tyr] and FTO/Al2O3[L-Tyr] electrodes respectively. PEDOT was deposited by electropolymerization onto FTO/Al2O3[D-Tyr] and FTO/Al2O3[L-Tyr] to enhance the sensitivity of the modified electrode, and the higher sensitivity electrodes were denoted as FTO/Al2O3[D-Tyr]/PEDOT and FTO/Al2O3[L-Tyr]/PEDOT. Afterward, cyclic voltammetry (CV) method was used to recognize for D and L-Tyr on the imprinted electrode. The enatioselectivities Abstract VII (E.S.) of FTO/Al2O3[D-Tyr] and FTO/Al2O3[L-Tyr] were 1.79 and 1.42, respectively. Further, SECM topography lended support for the higher adsorption ability of D-Tyr onto the FTO/Al2O3[D-Tyr]/PEDOT surface than that of L-Tyr under different adsorption times via the redox current responses of Fe(CN)6 3-/ Fe(CN)6 4-.Table of Contents Ⅰ Abstract (Chinese) Ⅲ Abstract (English) Ⅴ Table of contents Ⅷ List of tables ⅩⅢ List of figures ⅩⅣ Nomenclatures ⅩⅧ Abbreviations ⅩⅧ Symbols ⅩⅩⅠ Chapter 1 Introduction 1 1.1 Background of biosensor technology 1 1.1.1 Significance of biosensor technology 1 1.1.2 Commercial products 5 1.1.3 Potential and aspiration of biosensor technology 8 1.2 Introduction to molecularly imprinted polymers 9 1.2.1 The origin of molecularly imprinted polymers (MIPs) 9 1.2.2 Development and application of MIPs 11 1.3 Review on nicotine: the characteristic and sensing development 13 1.3.1 Brief introduction to nicotine (NIC) 13 1.3.2 Development of sensing NIC 13 1.4 Review on (+)-catechin ((+)-C): the characteristic and sensing method 17 1.5 Review on tyrosine: the characteristic and sensing development 21 1.6 Review on scanning electrochemical microscopy (SECM) 23 1.7 The framework and the motivations of this dissertation 24 Chapter 2 Theories 27 2.1 Theories of MIPs 27 2.1.1 The working principle of MIPs 27 2.1.2 Imprinting efficiency 31 2.2 Theories of amperometric sensing 32 2.2.1 General electrode reaction 32 2.2.2 Sensing theory 34 2.3 Theories of SECM 37 2.3.1 CVs for choosing applied potentials 37 2.3.2 Approach curves of SECM 38 Chapter 3 Experimental 41 3.1 Instruments 41 3.2 Reagents 43 3.3 Experimental procedures 45 3.3.1 Amperometric detection of the NIC on a modified planar ITO electrode 45 3.3.1.1 Pretreatment of substrates 45 3.3.1.2 Synthesis of TiO2 colloids 45 3.3.1.3 Preparation of NIC imprinted and non-imprinted electrodes by using TiO2 matrix 46 3.3.1.4 Electropolymerization of EDOT 46 3.3.1.5 Electrochemical measurements 49 3.3.1.5.1 Catalytic ability test 49 3.3.1.5.2 Polarization curve 49 3.3.1.5.3 Amperometric detection of the NIC 50 3.3.1.6 Topographical mappings by SECM 51 3.3.1.6.1 CVs for choosing applied potentials 51 3.3.1.6.2 Approach curve 51 3.3.1.6.3 Topographical mapping for ITO/TiO2/PEDOT and ITO/TiO2[NIC]/PEDOT electrodes 52 3.3.1.7 Adsorption test: affinity between NIC and the ITO/TiO2[NIC] electrode by FTIR 52 3.3.2 Amperometric detection of the NIC on a modified planar ITO electrode 54 3.3.2.1 On-chip microelectrodes fabrication 54 3.3.2.2 Preparation of NIC imprinted and non-imprinted WEs on-chips 55 3.3.2.3 Ag/AgCl RE preparation 58 3.3.2.4 Electrochemical measurements 58 3.3.2.4.1 Ag/AgCl OCP measurement 58 3.3.2.4.2 Polarization curve 58 3.3.2.4.3 Amperometric detection of the NIC and the interference effects 59 3.3.2.5 SECM topographical mappings 60 3.3.3 Amperometric detection of (+)-C based on a modified planar ITO electrode 61 3.3.3.1 Pretreatment of substrates 61 3.3.3.2 Preparation of (+)-C imprinted and non-imprinted electrodes 61 3.3.3.3 Electrochemical measurement 63 3.3.3.3.1 Adjusting pH value to change the (+)-C oxidation peak on an ITO electrode 63 3.3.3.3.2 Polarization curves 63 3.3.3.3.3 Amperometric detection 64 3.3.4 Enantioselective recognition of D and L-Tyr with a modified planar electrode 65 3.3.4.1 Pretreatment of substrates 65 3.3.4.2 Preparation of the D and L-Tyr imprinted electrodes 65 3.3.4.3 Electropolymerization of EDOT 66 3.3.4.4 Rebinding measurements 66 3.3.4.5 Topographical mappings adsorption test by using SECM 67 Chapter 4 Results and discussions 69 4.1 Amperometric detection of NIC on a modified planar ITO electrode 70 4.1.1 The catalytic effect of the conducting PEDOT 70 4.1.2 Amperometric detection of NIC and its interferent, COT 71 4.1.2.1 Choosing a suitable sensing potential based on the polarization curve 71 4.1.2.2 Sensing performance between the imprinted and the non-imprinted electrodes 73 4.1.2.3 Interference effect 73 4.1.3 Topographical mappings by SECM 77 4.1.4 SEM images as the additional evidence 79 4.1.5 FTIR studies 80 4.2 Amperometric detection of NIC on an on-chip modified microelectrode 82 4.2.1 Stability of Ag/AgCl RE 82 4.2.2 Amperometric detection of NIC, COT, and Glu 83 4.2.2.1 A polarization curve 83 4.2.2.2 Sensing performance for imprinted and non-imprinted microelectrodes 84 4.2.2.3 Interference effect 86 4.2.3 Topographical mappings by SECM 87 4.3 Amperometric detection of (+)-C based on a modified planar ITO electrode 91 4.3.1 The protection mechanism 91 4.3.2 Fabrication of ITO/PAN[(+)-C] and ITO/PAN modified electrodes 93 4.3.2.1 PAN as the imprinted polymer 93 4.3.2.2 Fixed charge capacities for ITO/PAN[(+)-C] and ITO/PAN modified electrodes 93 4.3.2.3 ITO/PAN[(+)-C] modified electrode as a catalytic electrode for (+)-C oxidation 97 4.3.3 Amperometric detection of (+)-C and its interferent 99 4.3.3.1 Sensing performance between ITO/PAN[(+)-C]and ITO/PAN modified electrodes 99 4.3.3.2 Interference effect 101 4.4 Enantioselective recognition of D and L-Tyr with a modified planar electrode 104 4.4.1 The rebinding abilities 104 4.4.2 Topographical mappings of adsorption test by using SECM 109 Chapter 5 Conclusions and suggestions 114 5.1 Conclusions 114 5.1.1 NIC sensing on NIC imprinted TiO2 modified electrodes 115 5.1.2 NIC sensing on on-chip NIC imprinted TiO2 modified electrodes 116 5.1.3 (+)-C sensing on (+)-C imprinted PAN modified electrodes 116 5.1.4 Summary of MIPs sensors with different methods: compared with published literatures 117 5.1.5 Recognition of D and L-Tyr with an Al2O3-modified molecularly imprinted electrode 120 5.2 Suggestions 121 5.2.1 Suggestion for amperometric (+)-C sensors 121 5.2.2 Suggestion for amperometric NIC sensors 121 5.2.3 Suggestion for enantioselective recognition of Tyr 122 5.2.4 Topographical mapping by using SECM 122 Chapter 6 References and author’s curriculum vitae 123 6.1 References 123 6.2 Author’s curriculum vitae 139 Appendix A Preparation of Ag/Ag+ RE 141 Appendix B Supplements inChapter 4 142 B.1 SEM photographs of ITO/TiO2[NIC]/PEDOT electrode 142 B.2 Calibration curve of (+)-C detection 143 List of Tables Table 1-1 Leading causes of death for persons ages 65 years and older by sex, 2002 [13]. 8 Table 1-2 A partial list of GC, and LC methods for the NIC detection reported in literatures. 15 Table 1-3 A partial list of other methods for the NIC detection reported in literature. 16 Table 1-4 A partial list of GC, and LC methods for the catechins detection reported in literatures. 19 Table 2-1 Comparative features of interactions between templates and monomers. 30 Table 2-2 Advantages and disadvantages of covalent and non-covalent imprinting [93]. 30 Table 3-1 The instruments used in this study 41 Table 3-2 The reagents used in this study. 43 Table 4-1 The effect of pH values on the rebinding selectivity of D- and L-Tyr imprinted film. 108 Table 5-1 A partial list of I.E. reported in the published literatures. 118 Table 5-2 A list of abbreviations, including monomers, transduction & substrate, initiator, and template documented in Table 5-1. 119 List of Figures Fig. 1-1 The statistical data in biosensors fields during last ten years (from year 1996 to 2005). (A) Applications of United States patents exhibited on the website of USPTO. (B) Referred papers reported on the Web of Science®. 3 Fig. 1-2 The statistical resources in the cause of death of Taiwanese during year 2004 demonstrate from Department of Health, Executive Yuan, R.O.C. (Taiwan).* The chronic liver disease. 4 Fig. 1-3 The commercial products (TaiDoc Technology Corporation) of biosensors, (A) blood glucose monitoring System; (B) blood pressure monitor; (C) ring pulse monitor. (http://www.taidoc.com) 6 Fig. 1-4 The lock and key model to describe the formation of an complex. The substrate has a shape that is complementary or fits into a preformed site on the enzyme. 10 Fig. 1-5 The developing trends of MIP technologies in SCI published papers reported on the Web of Science®. 10 Fig. 1-6 The chemical structures of NIC (A), and its metabolite COT (B). 15 Fig. 1-7 The partial chemical structures of polyphenols. 18 Fig. 1-8 The chemical structures of L, and D-Tyr. 21 Fig. 1-9 The framework of this dissertation. 26 Fig. 2-1 A well-known protocol of the MIPs working principle. (a) Non-covalent imprinting; (b) Covalent imprinting; (c) Extraction of template; (d) Rebind of template. 29 Fig. 2-2 Pathway of a general electrode reaction [95]. 33 Fig. 2-3 Processes in an electrode reaction represented as resistances. 36 Fig. 2-4 Concentration profiles on electrode surface and bulk solution. x=0 corresponds to the electrode surface and C* presents bulk region. 36 Fig. 2-5 A cyclic voltammogram before approaching, to obtain the applied potential at the tip and the substrate. 37 Fig. 2-6 The working principle of a SECM. 40 Fig. 3-1 Protocol of the NIC imprinted TiO2 electrode follows by PEDOT electrpolymerization. 47 Fig. 3-2 A typical three-electrode system employed throughout in this study. 48 Fig. 3-3 An object of SECM purchased from CH Instruments. 53 Fig. 3-4 A side view protocol of SECM during topographical mapping. 53 Fig. 3-5 The blueprint of the microchip. 56 Fig. 3-6 Simplified schematically process for microchip fabrication 57 Fig. 3-7 Simplified schematically process for microchip fabrication 57 Fig. 3-8 Schematic for the ITO/PAN[(+)-C]and the ITO/PAN modified electrode preparation. 62 Fig. 3-9 Protocol of the D-Tyr imprinted Al2O3 electrode follows by PEDOT electrpolymerization. 66 Fig. 4-1 (A) Cyclic voltammograms in a PBS solution containing 5 mM NIC and 0.1 M KCl executed on the (a) ITO/TiO2[NIC]/PEDOT, (b) bare ITO electrode, and (c) ITO/TiO2[NIC] electrode. (B) Linear sweep voltammograms: the ITO/TiO2[NIC]/PEDOT and a bare ITO were employed to plot the polarization curve. Here shows the net current response carried out in a PBS solution with 5 mM NIC. 72 Fig. 4-2 Sensing performance for the ITO/TiO2/PEDOT and the ITO/TiO2[NIC]/PEDOT electrodes. (A) A typical i-t curve for NIC oxidation on the ITO/TiO2/PEDOT electrode. (B) A typical i-t curve for NIC oxidation on the ITO/TiO2[NIC]/PEDOT electrode. (C) Calibration curves obtained from the equilibrium currents, as shown in (A) & (B). 75 Fig. 4-3 (A) The interference effect: curves (a), (b), and (c) were the oxidation current responses for the added NIC alone, equimolar coexistence of NIC and COT mixture, and COT alone, respectively. (B) Chemical structures of NIC and COT. 76 Fig. 4-4 (A) A cyclic voltammogram before approaching to obtain the applied potential at the tip and the substrate. (B) An approach curve before approaching, allowing the tip to come close to the mapping substrates. (C) 3-D mapping topographies on both substrates (the ITO/TiO2/PEDOT and the ITO/TiO2[NIC]/PEDOT electrodes). 78 Fig. 4-5 SEM images of the TiO2 films: (A) ITO/TiO2; (B) ITO/TiO2[NIC]. 79 Fig. 4-6 (A) A FTIR spectrum to determine the interaction between NIC and its imprinted TiO2 electrode. (B) The schematic for the hydrogen bond formed between nitrogen in the NIC and hydrogen atom on the hydroxyl group of the external site on a TiO2 particle. The inset table was summarized from previous literature [105]. 81 Fig. 4-7 Open circuit potential variation between the on-chip Ag/AgCl and an Ag/AgCl/Sat’d KCl. 85 Fig. 4-8 Linear sweep voltammograms: the Pt/TiO2[NIC]/PEDOT was served as working electrode (a) The background current (PBS solution) was recorded. (b) The current for the addition of 5 mM NIC was recorded. (c) The net current was obtained by subtracting curves (a) from (b). 85 Fig. 4-9 Sensing performance for the Pt/TiO2/PEDOT and the Pt/TiO2[NIC]/PEDOT electrodes. (A) A typical i-t curve for NIC oxidation on the Pt/TiO2/PEDOT electrode. (B) A typical i-t curve for NIC oxidation on the Pt/TiO2[NIC]/PEDOT electrode. (C) Calibration curves obtained from the equilibrium currents, as shown in (A) & (B). 88 Fig. 4-10 Interference effects: same concentration of NIC, COT and Glu. 89 Fig. 4-11 (A) A cyclic voltammogram before approaching, to obtain the applied potentials at the tip and the substrate. (B) An approach curve before approaching, allowing the tip to come close to the mapping substrates. (C) 3-D mapping topographies on both substrates (the Pt bar and the Pt/TiO2[NIC]/PEDOT microelectrodes). The applied potential at the tip and the substrates were 0 V and 0.5 V (vs. Ag/AgCl/sat’d KCl), respectively. 90 Fig. 4-12 Cyclic voltammograms of a bare ITO electrode in the aqueous solutions. The bulk solution contains 0.5 mM (+)-C under different pH values which were adjusted to 5.70, 2.88, 1.86, 0.29, and -0.33. The scan rate was 20 mV/s. 92 Fig. 4-13 (A) The ITO/PAN[(+)-C] films were washed out using 5 ml methanol for 20 min to remove the (+)-C. (B) The accumulated amount of (+)-C washed out at each extraction. 95 Fig. 4-14 Cyclic voltammograms of an ITO/PAN[(+)-C] (after extraction) and an ITO/PAN modified electrodes in phosphate buffer solution (pH = 6.54) containing 0.1 M KCl to fix the same charge capacities for both electrodes. The scan rate was 50 mV/s. 96 Fig. 4-15 (A) A polarization curve for (+)-C sensing at a bare ITO electrode. The data were obtained by applying a potential step that began from 0 to 0.8 V (vs. Ag/AgCl/sat’d KCl). (B) A polarization curve for (+)-C sensing at the ITO/PAN[(+)-C] modified electrode. It was also obtained by applying a potential step that began from 0 to 0.4 V. 98 Fig. 4-16 (A) A typical calibrated current vs. concentration curve for (+)-C sensing. Curves (a), (b), and (c) were the ITO/PAN[(+)-C] modified electrode, the ITO/PAN modified electrode and the ITO electrode, respectively, which were exerted as the working electrode. (B) The interference effect, curves (a), (b), and (c) were the oxidation current responses for the added (+)-C alone, equimolar coexistence of (+)-C and CAF mixture, and CAF alone, respectively. 102 Fig. 4-17 A schematic for the affinity, including matching shape and the non-covalent bond interaction, between (+)-C and its imprinted film. 103 Fig. 4-18 Chemical structures of (A) (+)-C, and (B) CAF. 103 Fig. 4-19 Cyclic voltammograms of 1 mM of D- and L-Tyr executed on the FTO/Al2O3[D-Tyr]/PEDOT in a PBS solution based on different pHs (A) pH=2.2, (B) pH=7.4 and (C) pH=11.8. 106 Fig. 4-20 Cyclic voltammograms of 1 mM of D- and L-Tyr executed on the FTO/Al2O3[L-Tyr]/PEDOT in a PBS solution based on different pHs (A) pH=2.2, (B) pH=7.4 and (C) pH=11.8. 107 Fig. 4-21 The plot representing the rebinding ability of D- and L-Tyr enantiomers on FTO/Al2O3[D-Tyr]/PEDOT and FTO/Al2O3[L-Tyr]/PEDOT at different pH. 108 Fig. 4-22 (A) A cyclic voltammogram before approaching, to obtain the applied potential at the tip and the substrate.(B) An approaching curve before approaching, allowing the tip to come close to the mapping substrates. 111 Fig. 4-23 3-D mapping topographies of FTO/Al2O3[D-Tyr]/PEDOT for (A) background response, (B) 1 mM L-Tyr for 15 min adsorption, and (C) 1 mM L-Tyr for 30 min adsorption. 112 Fig. 4-24 3-D mapping topographies of FTO/Al2O3[D-Tyr]/PEDOT for (A) background response, (B) 1 mM D-Tyr for 15 min adsorption, and (C) 1 mM D-Tyr for 30 min adsorption. 113 Fig. A-1 The relative electrode potentials for some REs used in the nonaqueous solution systems. 141 Fig. B-1 (A) Topside view, and (B) lateral view of SEM photographs of ITO/TiO2[NIC]/PEDOT electrode. 142 Fig. B-2 A absorbance spectra of the (+)-C. 143 Fig. B-3 A typical calibrated curve for (+)-C detection. 14413272681 bytesapplication/pdfen-US分子模版尼古丁兒茶素微電極電流式感測酪胺酸循環伏安法掃瞄式電化學顯微鏡Amperometry(+)-CatechinCyclic voltammetryMicroelectrodeMolecularly imprinted polymers (MIPs)NicotineScanning electrochemical microscopy (SECM)Tyrosinethesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/52374/1/ntu-95-R93524037-1.pdf