三氧化鎢-二氧化鈦、奈米碳管結合高分子複合薄膜修飾電極的製備及電化學性質的研究

Preparation, Characterization and Electroanalytical Application of WO3-TiO2, Multi-walled Carbon Nanotubes with Polymer Hybrid Film Modified Electrodes

徐姵琪(Pei-Chi Hsu)

指導教授 ： 陳生明

國立臺北科技大學/工程學院/化學工程研究所/碩士(2012年)

摘要

第一部分
二氧化鈦混合不同比例的三氧化鎢成WO3-TiO2複合膜並製備在銦錫氧化物(ITO)電極上，TiO2 : WO3 = 9 : 3 (v/v)在照光條件下的電流值為5.44 mA，這個比例和其他比例比起來有較高的光催化活性，所以我們選擇這個比例做後續的實驗。在本篇研究中，用去甲腎上腺素(NEP)和核黃素(維他命B2)的電化學氧化和還原作為多功能生物感測器。二氧化鈦對分析物具有增強光電催化活性的效果，用原子力顯微鏡觀察修飾電極的表面型態，顯示出ITO上塗佈著WO3和TiO2，二氧化鈦的存在增強其負載和穩定性。電化學阻抗頻譜圖是運用擴散係數的值和經由氧化還原反應造成電子轉移動力學的一些訊息。用循環伏安法(CVs)和微分脈衝伏安法(DPVs)測定分析物，DPVs不只增加了電催化電流的線性濃度範圍，也降低了測量氧化或還原干擾的過電位。我們模擬去甲腎上腺素和核黃素同時存在的複雜的系統，在pH 7下WO3-TiO2修飾電極對真實樣品去甲腎上腺素注射劑和維他命B群錠的偵測，同樣顯示氧化和還原的電流値。

第二部分
在這篇研究中，用多層奈米碳管-聚乙烯亞胺(MWCNT-PEI)複合物修飾玻璃碳電極(GCE)，製成的伏安感測器可以用來偵測氯丙嗪(CPM)。MWCNT-PEI複合物是藉由簡單的超聲震盪製備而成。使用未官能基化的MWCNT。PEI可以幫助MWCNT形成穩定分散的複合材料。電化學阻抗頻譜圖研究顯示MWCNT-PEI膜的高導電性。在電位0.7 V的pH 7 PBS中，CPM在MWCNT和 MWCNT-PEI修飾GCE電極顯示不可逆的氧化峰。MWCNT-PEI對CPM顯示優良的電分析特性，藉由微分脈衝伏安法(DPV)的偵測，可得偵測極限為10 nM，靈敏度為1.3 µA µM−1 cm−2。MWCNT-PEI膜對抗壞血酸不會顯示任何特徵峰，然而，此膜對多巴胺、尿酸、乙醯氨基苯酚和CPM在相同濃度下，有明顯且分離的特徵峰。此膜顯示好的再現性，並對真實樣品的偵測顯示明顯的性能。

第三部分
在這篇研究中，因官能基化多層奈米碳管(f-MWCNTs)和聚谷胺酸(PGA)間作用，發展了一個可以簡單、快速、靈敏且準確的偵測普魯卡因和兒茶酚的方法。PGA/f-MWCNTs修飾電極對藥品的定量和生理研究有關。循環伏安法(CVs)、電化學阻抗頻譜圖(EIS)和掃描式電子顯微鏡(SEM)用來了解修飾電極的製備過程。CVs在氧化峰電流和催化物濃度間有好的線性關係(r>0.99)，普羅卡因的線性範圍在9.0×10−7– 8.3×10−5 M，兒茶酚的線性範圍在8.2×10−5– 2.3×10−4 M。計時安培法顯示普羅卡因和兒茶酚的氧化電流。由於普羅卡因和兒茶酚對PGA高度的親和力和感測高度的穩定性，使生物感測器具有好的靈敏度、可接受的再現性和穩定性。線性掃描伏安法(LSV)可以將兩種化合物的伏安峰電流分離，使我們可以同時偵測。因此，f-MWCNTs和PGA間的特別鍵結基團相結合，替生物電化學設備的製造提供了一個有效及有前景的平台。

關鍵字

二氧化鈦(TiO2) ； 三氧化鎢(WO3) ； 去甲腎上腺素(NEP) ； 核黃素(維他命B2 ) ； 修飾電極 ； 光電催化 ； 多層奈米碳管 ； 聚乙烯亞胺 ； 氯丙嗪官能基化多層奈米碳管 ； 聚谷胺酸 ； 普羅卡因 ； 兒茶酚 ； 電催化

並列摘要

Part1
The titanium dioxide (TiO2) , mixed different ratio tungsten oxide (WO3) hybrid film WO3-TiO2 was prepared on indium tin oxide (ITO) electrode. TiO2 : WO3 = 9 : 3 (v/v) group current value was 5.44 mA under irradiation conditions. This group showed highest photocatalytic activity than others, we selected to optimize us in follow-up experiment. In this paper, the electrochemical oxidation and reduction of norepinephrine (NEP) and riboflavin (Vitamin B2 ) as multi-functionalized biosensor. The TiO2 exhibited a promising enhanced photoelectrocatalytic activity towards analytes. To measure the surface morphology of the modified electrode by using atomic force microscopy (AFM) , which revealed that WO3 and TiO2 were coated on ITO. The presence of TiO2 enhances the loaded and stability. Electrochemical impedance spectroscopy (EIS) applied diffusion coefficient values and some information about the kinetics of electron transfer during the redox reactions. Cyclic voltammograms (CVs) and Differential pulse voltammetry (DPVs) were used for the determination of analytes. DPVs not only increased the electrocatalytic current linear concentration range, also lowered the overpotential to oxidation or reduction the interferences in the measurements. We simulated more complex system if both norepinephrine and riboflavin were present simultaneously. It also exhibited oxidation and reduction peaks for norepinephrine injection and B complex tablet’s real samples determination in pH 7.0 at WO3-TiO2 modified electrode.

Part2
We report the fabrication of a voltammetric sensor for the determination of chlorpromazine (CPM) based on multiwalled carbon nanotube-poly(ethyleneimine) (MWCNT-PEI) composite modified glassy carbon electrode (GCE). The MWCNT-PEI composite was prepared by a simple ultrasonication method. The MWCNT was used without functionalization. Formation of composite with PEI helps MWCNT to form a stable dispersion. Electrochemical impedance spectroscopy studies reveal the high conductance of MWCNT-PEI film. CPM shows irreversible oxidation peak at MWCNT and MWCNT-PEI modified GCE in pH 7 at 0.7 V. MWCNT-PEI shows excellent electroanalytical properties towards CPM and can detect as low as 10 nM level by differential pulse voltammetry (DPV) with a sensitivity of 1.3 µA µM−1 cm−2. The MWCNT-PEI film does not show any peak for Ascorbic acid. However, it shows well defined and well separate peaks for dopamine, uric acid, p-acetamidophenol and CPM in the same solution. The fabrication method shows good reproducibility. The film shows appreciable performance in real sample analysis.

Part3
In this paper, a simple, rapid, sensitive, and accurate method for detecting procaine and catechol was developed based on functionalized multi-walled carbon nanotube (f-MWCNTs) and poly-glutamic acid (PGA) interactions. For pharmaceutical quality control and physiology research was developed using a PGA/f-MWCNTs modified electrodes. Cyclic voltammetry (CVs), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) were applied to characterize the assembly process of the modified electrode. CVs of good linearity (r>0.99) between oxidation peak current and concentration was obtained in the range of 9.0 × 10−7– 8.3 × 10−5 M for procaine and 8.2 × 10−5– 2.3 × 10−4 M for catechol in pH 7.0 PBS. The amperometric results revealed that procaine and catechol, respectively, showed well-defined oxidation current. Due to the high affinity of procaine and catechol for PGA and high stability of the propounded sensing platform, the fabricated biosensor achieved ultrasensitive detection with good sensitivity, acceptable reproducibility and stability. Linear sweep voltammetry (LSV) was well separation of the current peaks for these two compounds in voltammetry enables us to simultaneously determine them. Therefore, the combination of f-MWCNT and the special binding group between PGA provides an efficient and promising platform for the fabrication of bioelectrochemical device.

並列關鍵字

Titanium dioxide (TiO2) ； Tungsten oxide (WO3) ； Norepinephrine (NEP) ； Riboflavin (Vitamin B2) ； Modified electrodes ； Photoelectrocatalysis ； MWCNTs ； poly(ethyleneimine) ； Chlorpromazine ； Functionalized MWCNTs ； Poly-glutamic acid ； Procaine ； Catechol ； Electrocatalysis

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