指導教授：何國川臺灣大學：化學工程學研究所李達人Li, Ta-JenTa-JenLi2014-11-252018-06-282014-11-252018-06-282014http://ntur.lib.ntu.edu.tw//handle/246246/261186在本論文中，我們選擇不同的化學或生物分子，包含碘酸根、多巴胺(DA)、糖化血紅素(HbA1c)以及亞硝酸鹽，然後利用不同的材料製備化學修飾電極感測之。 碘酸根常添加於食鹽中以防止甲狀腺腫大。我們首次製備一導電高分子聚二氧乙烯噻吩(PEDOT)與氧化還原媒子核黃素腺嘌呤二核苷酸(FAD)複合薄膜以修飾玻璃碳電極(GCE)。此修飾電極定名為GCE/PEDOT-FAD。循環伏安法(CV)以及電化學式石英震盪微天秤(EQCM)實驗顯示，FAD在PEDOT聚合的過程中摻雜至其中。製備修飾電極的最佳鍍膜圈數決定為9圈。我們利用定電位法感測碘酸根，GCE/PEDOT-FAD的靈敏度為0.78 μA μM-1 cm-2，線性範圍為4-140 μM，而偵測下限(LOD)為0.16 μM。與文獻中單獨利用FAD感測碘酸根所得的結果比較，本研究將PEDOT與FAD結合改善了感測器的靈敏度與偵測下限。我們最後將此感測器應用於偵測鹽產品中的碘酸根。 DA為一重要的神經傳導物質，它的分泌異常將導致一些疾病如巴金森氏症及杭亭頓氏舞蹈症。我們利硼摻雜奈米碳管(BCNTs)修飾網印碳電極(SPCE)。BCNTs是利用一常壓的碳熱反應合成，其中氨氣(在氬氣的氛圍中)作為蝕刻氣體在多壁奈米碳管(MWCNT)中產生缺陷，三氧化二硼作為硼源。我們利用0.5wt.%的Nafion®溶液將奈米碳管分散以修飾SPCE。我們首度探討硼摻雜量與BCNT催化活性之間的關聯性，發現BCNT (B 2.1 at.%)對於DA有最佳的催化效果。旋轉盤電極分析顯示，摻雜2.1 at.%的硼於MWCNT中分別提升它的電活性面積(Ae)及標準速率常數(k0)約13%。我們利用BCNT (B 2.1 at.%)修飾的SPCE 感測DA，相較於利用CV，以微分脈衝伏安法(DPV)進行感測能夠得到較高的靈敏(35.65 μA cm-2 μM-1)與較低的偵測下限(0.017 μM)。干擾研究方面，我們探討抗壞血酸以及尿酸對於DA感測的影響。 HbA1c是評估長期糖尿病監控情形的重要指標。我們選擇網印金電極(SPGE)為電極基材，然後以滴覆的方式將Nafion®修飾其上當作選擇性物質。二茂鐵硼酸(FcBA)則用來辨識HbA1c並且提供氧化還原電流訊號。我們發現修飾Nafion®能夠防止血紅素(Hb)吸附於SPGE上，主要的原因為Nafion®與Hb之間的電性排斥。實驗上決定Nafion®的最佳修飾層數為3層。我們以人類全血進行真實樣品測試。我們也探討與HbA1c結合對於FcBA氧化還原峰電流造成的影響，並且證實與HbA1c結合是造成FcBA氧化還原峰電流下降的主因。此外，由於還原峰電流的下降量較氧化峰電流明顯，我們推論HbA1c與氧化態的FcBA(FcBA+)之間有較強的作用力。 亞硝酸鹽是評估泌尿道感染的重要指標。為了臨床應用的方便性，我們嘗試製備電化學式感測器以偵測不稀釋尿液中的亞硝酸鹽。我們利用導電高分子聚3,4-(2,2-二乙基丙烯)二氧基噻吩(PProDOT-Et2)修飾SPGE以提升它的性能表現。由於亞硝酸鹽不存在健康人的尿液中，我們將亞硝酸鹽添加於尿液樣品中進行偵測。我們發現利用CV在不稀釋的尿液中最低可偵測的濃度約為250 μM，此值較試紙呈色方法的最低可偵測濃度(20 μM)來得高。我們將利用不同的電極修飾物質以及不同的電化學感測方法改善感測器的性能表現。In this dissertation, different chemical or biological molecules, including iodate, dopamine (DA), glycated hemoglobin (HbA1c), and nitrite were selected as the targets, and different materials were used to prepare the chemically modified electrodes (CMEs) for sensing them. Iodate is often added in table salts to prevent goiter. A composite film composed of the conducting polymer, poly(3,4-ethylenedioxythiophene) (PEDOT) and the mediator, flavin adenine dinucleotide (FAD), was prepared for the first time for modifying the glassy carbon electrode (GCE). This modified electrode was designated as GCE/PEDOT-FAD. Cyclic voltammetry (CV) and electrochemical quartz crystal microbalance (EQCM) analyses revealed that FAD was doped into the PEDOT film during the electrodepositon process. The optimal cycle number for preparing the modified electrode was determined to be 9. The amperometric detection of iodate was performed; the GCE/PEDOT-FAD showed a sensitivity of 0.78 μA μM-1 cm-2, a linear range of 4-140 μM, and a limit of detection (LOD) of 0.16 μM for iodate. Compared with the results in the literature obtained by using single FAD for sensing iodate, it can be said that the combination of PEDOT with FAD significantly improved the sensitivity and LOD. Eventually, the GCE/PEDOT-FAD was applied to detect iodate in a salt product. DA is a vital neurotransmitter; its abnormal transmission has been associated with several neurological disorders such as Parkinson’s disease and Huntington’s chorea. Boron doped carbon nanotubes (BCNTs) were utilized for modifying the screen printed carbon electrode (SPCE). The BCNTs were synthesized by an atmospheric carbothermal reaction, in which ammonia (in argon atmosphere) was used as the etching gas to create defects in the multi-walled carbon nanotubes (MWCNT), and boron trioxide was used as the boron source. Each CNT sample was dispersed in 0.5 wt.% Nafion® solution. The relationship between the boron doped amount and the electrocatalytic activity of the BCNT was explored for the first time; it was found that the oxidation peak current of DA is the highest on the BCNT (B 2.1 at.%) modified SPCE. Rotating disk electrode (RDE) analysis revealed that doping of 2.1 at.% boron into the MWCNT upgrades the electroactive surface area (Ae) and the standard rate constant (k0) by ca. 13%, respectively. DA sensing on the BCNT (B 2.1 at.%) modified SPCE was conducted; higher sensitivity (35.65 μA cm-2 μM-1) and lower LOD (0.017 μM) were obtained by using the differential pulse voltammetry (DPV), with respect to those obtained by using CV. The interfering effects of ascorbic acid and uric acid on DA sensing were also studied. HbA1c is an important index for assessing the long-term condition of diabetes monitoring. Screen printed gold electrode (SPGE) was chosen as the substrate, and Nafion® was dropped coated onto it as a selective material. Ferroceneboronic acid (FcBA) was utilized for recognizing HbA1c and providing the redox signal. Experimental results showed that the modification of Nafion® film effectively blocked the adsorption of hemoglobin (Hb) onto the SPGE; the main reason could be charge repulsion between Hb and Nafion®. The optimal layer of Nafion® film for modifying the SPGE was determined to be 3. Human whole blood was used for real sample test. The effect of HbA1c binding on the redox signal of FcBA was also investigated. It was verified that the binding with HbA1c is the main reason for causing the decrement of the redox signal. Furthermore, since the decrement of the reduction peak current is larger than that of the anodic peak current, it was deduced that HbA1c has stronger interaction with the oxidized FcBA (FcBA+). Nitrite is a significant index for assessing the urinary tract infection (UTI). For the convenience of clinical use, we tried to fabricate an electrochemical sensor to detect nitrite in the undiluted human urine samples. The conducting polymer, poly(3,4-(2’,2’-diethylpropylene)dioxythiophene) (PProDOT-Et2), was utilized to modify the SPGE to enhance its sensor performance. Since nitrite does not exist in the urine from healthy persons, nitrite was spiked into the urine samples for detection. It was found that the lowest concentration of nitrite that can be detect in the human urine by using the CV method is 250 μM, which is higher than the value can be achieved by the test paper coloring method, 20 μM. Different materials and different electrochemical sensing methods will be used to improve the sensor performance.致謝 I 中文摘要 III Abstract V Table of contents VIII List of tables XVII List of figures XIX Nomenclatures XXXI Chapter 1 Introduction 1 1.1 Preface 1 1.2 Introduction to sensors 3 1.2.1 Recognition elements 5 1.2.2 Transducers 8 1.2.2.1 Electrochemical transducers 8 1.2.2.2 Optical transducers 11 1.3 Chemically modified electrodes 13 1.3.1 Polymers for modifying the electrodes 13 1.3.2 Carbon materials for modifying the electrodes 14 1.3.3 Redox mediators for modifying the electrodes 17 1.4 Scope of this dissertation 19 Chapter 2 Literature Review and Research Motivations 25 2.1 Electrochemical iodate sensor 25 2.1.1 Importance of iodate and traditional analytical methods for detecting it 25 2.1.2 Preparation of modified electrodes for the reduction reaction of iodate 25 2.1.3 Motivations of this research 26 2.2 Electrochemical DA sensor 28 2.2.1 Importance of DA and traditional analytical methods for detecting it 28 2.2.2 Preparation of modified electrodes for the reduction reaction of DA 28 2.2.3 Doping of carbon nanotubes to enhance their electrocatalytic activities 29 2.2.4 Motivations of this research 31 2.3 Electrochemical HbA1c sensor 33 2.3.1 Importance of HbA1c and traditional analytical methods for detecting it 33 2.3.2 Formation of HbA1c 34 2.3.3 Preparation of modified electrodes for detecting HbA1c or fructosyl valine 34 2.3.4 Motivations of this research 38 2.4 Electrochemical nitrite sensor 40 2.4.1 Importance of nitrite and traditional methods for detecting it 40 2.4.2 Urinary tract infection 41 2.4.3 Preparation of modified electrodes for oxidation sensing of nitrite 41 2.4.4 Motivations of this research 42 Chapter 3 General experimental descriptions 45 3.1 Materials 45 3.2 Instruments 50 3.3 Solutions 51 3.4 Instrumental analyses 52 3.4.1 Material characterizations 52 3.4.1.1 Atomic force microscopy 52 3.4.1.2 Raman spectroscopy 52 3.4.1.3 Scanning electron microscope-energy dispersive X-ray spectrometer 52 3.4.1.4 Transmission electron microscope-electron energy loss spectroscopy 52 3.4.1.5 X-ray photoelectron spectroscopy 53 3.4.2 Electrochemical analyses 53 3.4.2.1 Three-electrode system 53 3.4.2.2 Electrochemical quartz crystal microbalance analysis 53 3.4.2.3 Rotating disk electrode analysis 55 3.5 Principles of the electrochemical methods 56 3.5.1 Cyclic voltammetry 56 3.5.2 Differential pulse voltammetry 57 3.5.3 Chronoamperometry 58 Chapter 4 Modification of Glassy Carbon Electrode with a Polymer/Mediator Composite and Its Application for the Electrochemical Detection of Iodate 59 4.1 Overview of chapter 4 59 4.2 Experimental details of chapter 4 60 4.2.1 Electrodeposition of films of PEDOT-FAD and PEDOT on the GCE 60 4.2.2 Amperometric detection of iodate 61 4.2.3 EQCM analysis to study the effect of FAD on the electrodeposition of PEDOT 61 4.3 Results and discussion 62 4.3.1 Combination of PEDOT with FAD to modify the GCE 62 4.3.2 Electrodeposition of PEDOT with and without adding FAD: EQCM analysis 65 4.3.3 SEM characterization of the PEDOT and PEDOT-FAD films 68 4.3.4 AFM characterization of the PEDOT and PEDOT-FAD films 69 4.3.5 UV-vis characterization of the PEDOT and PEDOT-FAD films 70 4.3.6 Determination of the optimal cycle number for preparing the GCE/PEDOT-FAD 70 4.3.7 Estimation of the surface coverage of FAD 73 4.3.8 Effect of pH value on the electrochemical properties of the GCE/PEDOT-FAD 75 4.3.9 Amperometric detection of iodate 77 4.3.10 Long-term stability of the GCE/PEDOT-FAD 81 4.3.11 Interference studies and real sample analysis 82 4.4 Summary of chapter 4 84 Chapter 5 Controlling the Electrocatalytic Activity of Multi-walled Carbon Nanotubes by Boron Doping for Electrochemical Sensing of Dopamine 85 5.1 Overview of chapter 5 85 5.2 Experimental details of chapter 5 86 5.2.1 Synthesis of BCNTs with different boron doped amounts 86 5.2.2 Modification of the SPCE by Nafion® and CNT 86 5.2.3 Electrochemical sensing of DA by CV and DPV 87 5.2.4 Preparation of the modified electrodes for RDE analysis 87 5.3 Results and discussion 88 5.3.1 XPS analysis of the BCNTs 88 5.3.2 HRTEM and EELS analyses of the BCNTs 89 5.3.3 EELS elemental mapping of the BCNT 90 5.3.4 Dispersion of the CNTs and preparation of the modified electrodes 92 5.3.5 Roles of Nafion® and MWCNT playing in the electrocatalysis of DA oxidation 92 5.3.6 Electrocatalytic activities of the BCNTs toward DA oxidation 94 5.3.7 SEM observation of the bare SPCE and the modified SPCEs 98 5.3.8 RDE analysis for interpreting the enhancement of ipa by boron doping 99 5.3.9 Scan rate effect on the redox reaction of DA on the SPCE/Nafion®-BCNT 102 5.3.10 Reaction of DA on the SPCE/Nafion®-BCNT at different pH values 103 5.3.11 Voltammetric sensing of DA on the SPCE/Nafion®-BCNT 105 5.3.12 Interference studies 108 5.3.13 Repeatability, reproducibility and the long-term stability tests 110 5.4 Summary of chapter 5 112 Chapter 6 Electrochemical Sensing of Glycated Hemoglobin by Utilizing Ferroceneboronic Acid and Nafion® 113 6.1 Overview of chapter 6 113 6.2 Experimental details of chapter 6 114 6.2.1 Quantification of the total Hb in the human whole blood 114 6.2.2 Preparation of the Nafion® modified SPGE 114 6.2.3 Correlating the concentration of HbA1c with the cathodic peak of FcBA 114 6.2.4 Investigation of the effect of HbA1c binding on the redox peak current of FcBA 115 6.3 Results and discussion 116 6.3.1 Quantification of total Hb in the human whole blood 116 6.3.2 Electrochemical behaviors of FcBA on the bare SPGE 117 6.3.3 Illustration of the HbA1c sensing method developed in this study 119 6.3.4 Determination of the optimal Nafion® film layer 120 6.3.5 SEM observation of the thickness of Nafion® films 122 6.3.6 Sensing HbA1c in the human whole blood 124 6.3.7 Study the effect of HbA1c binding on the electrochemical property of FcBA 126 6.4 Summary of chapter 6 132 Chapter 7 Preparation of a Conducting Polymer Modified Screen Printed Gold Electrode for Sensing Nitrite in Undiluted Human Urine Samples 133 7.1 Overview of chapter 7 133 7.2 Experimental details of chapter 7 134 7.2.1 Preparation of the SPGE/PProDOT-Et2 134 7.2.2 Experimental setup of drop-in nitrite sensing 134 7.2.3 Electrochemical nitrite sensing in undiluted human urine samples 134 7.3 Results and discussion 136 7.3.1 Electrodeposition of PProDOT-Et2 onto the SPGE 136 7.3.2 Electrochemical oxidation of nitrite on the SPGE and SPGE/PProDOT-Et2 136 7.3.3 SEM observation of the bare SPGE and SPGE/PProDOT-Et2 138 7.3.4 Effect of pH value on nitrite sensing on the SPGE/PProDOT-Et2 139 7.3.5 Interference studies 139 7.3.6 Electrochemical sensing of nitrite in undiluted human urine samples 142 7.3.7 Traditional coloring method for sensing nitrite in undiluted human urine 143 7.3.8 Integrating the nitrite sensor with its corresponding readout circuit 143 7.4 Summary of chapter 7 144 Chapter 8 Conclusions and Suggestions 145 8.1 Conclusions 145 8.2 Suggestions 148 Chapter 9 References 151 Appendix A Preparation of a Novel Molecularly Imprinted Polymer by the Sol-gel Process for Sensing Creatinine 187 A.1 Introduction 187 A.1.1 Importance of creatinine and traditional methods for detecting it 187 A.1.2 Preparation of molecularly imprinted polymers for sensing creatinine 188 A.1.3 Motivations of this research 190 A.2 Experimental details of appendix A 192 A.2.1 Preparation of the molecularly imprinted polymer for Cre 192 A.2.2 Measurement of Al3+ in the extraction solutions of Cre 192 A.2.3 Determination of suitable adsorption time 192 A.2.4 Adsorption studies to evaluate the imprinting efficiency of the MIPCre 192 A.2.5 Interference studies to evaluate the selectivities of MIPCre and NIP 193 A.2.6 Measurement of the specific surface area of MIPCre 193 A.2.7 Cre desorption and re-adsorption experiments to assess the reusability of MIPCre 194 A.3 Results and discussion 194 A.3.1 Design and preparation of the MIPCre 194 A.3.2 Determination of suitable adsorption time 199 A.3.3 Cre adsorption studies to evaluate the imprinting efficiency of MIPCre 200 A.3.4 Interference studies to evaluate the selectivity of MIPCre and NIP 201 A.3.5 Effect of Al3+ concentration on the adsorbed amount of Cre by MIPCre 203 A.3.6 Confirmation of the Cre adsorption ability and reusability of MIPCre 206 A.3.7 Effect of TEOS concentration on the adsorbed amount of Cre by MIPCre 207 A.4 Summary of appendix A 208 A.5 References of appendix A 209 Appendix B Synthesizing Graphenes with Different Boron Doped Amounts and Exploring their Electrochemical Properties 213 B.1 Introduction 213 B.1.1 Using boron doped graphene to modify electrodes for electrochemical sensing 213 B.1.2 Motivations of this study 215 B.1 Experimental details of this appendix B 216 B.2.1 Synthesis of graphenes with different boron doped amounts 216 B.2.2 Dispersion of the graphene samples 216 B.2.3 SEM observation of the graphene samples 217 B.2.4 Preparation of the graphene modified SPCEs 217 B.2.5 Study the electrochemical property of the graphene samples 217 B.3 Results and discussion 217 B.3.1 Observation of the surface morphologies of the graphene samples 217 B.3.2 Background current of the graphene modified SPCEs 219 B.3.3 Redox reaction of Fe(CN)63-/4- on the graphene modified SPCEs 220 B.3.4 Redox reaction of DA on the graphene modified SPCEs 222 B.4 Summary of appendix B 223 B.5 References of appendix B 224 Appendix C Curriculum Vitae 22518149913 bytesapplication/pdf論文公開時間：2016/08/25論文使用權限：同意有償授權(權利金給回饋學校)碳材化學修飾電極導電高分子摻雜電化學式感測器氧化還原媒子[SDGs]SDG3thesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/261186/1/ntu-103-D98524002-1.pdf