奈米材料結合高分子與酵素複合膜修飾電極的製備及其電催化反應研究

Preparation, Characterization of Nano Materials with Polymer, Enzyme Composite Film Modified Electrodes and Their Electrocatalytic Applications

何雅惠(Ya-Hui Ho)

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(2010年)

摘要

本研究主要分為三部份來討論。第一部份：我們成功研發出新穎的材料，利用電聚合製備poly (DDS) 摻雜了奈米TiO2 複合修飾薄膜在ITO導電玻璃上，此修飾電極對菸鹼醯胺核苷酸 (NADH) 有良好的光及電催化反應，且修飾薄膜在照光5分鐘後對NADH催化的電流訊號有明顯的增加，以循環伏安法 ( CV ) 對NADH 做分析，以 CV 方法測定下 NADH 的濃度線性範圍為5×10-8 到 1.2×10-7 M，此外，利用原子力顯微鏡 ( AFM ) 及掃描式電子式顯微鏡 ( SEM ) 進行修飾薄膜表面分析，由 XRD 證明 TiO2 為銳鈦礦型。本實驗還用光激發對電化學阻抗頻譜分析法 ( EIS ) 做光電催化的特性影響加以探討。第二部份：以簡單的方式製備酵素薄膜修飾電極，首先把多層奈米碳管(MWCNTs) 掺雜胭脂紅酸(Carminic acid)改質成CACNT，由UV 吸收光譜圖得知CACNT有鍵結上Carminic acid。將PLL固定在CACNT修飾的玻璃碳電極上，以吸附方式接上乙醇去氫酶 (ADH)。以循環伏安法(CV)測定乙醇的電催化反應( pH = 8.2 PBS )，濃度線性範圍為2.5×10-2 到 3.01 M。利用EIS分析結果知道有MWCNTs 的存在可以增加表面積並且降低電阻增加電子傳遞速率。從 AFM 和 SEM 的結果可以清楚看出ADH / PLL / CACNT 和不同層薄膜的表面形貌。然而，排除干擾物質的訊號，此薄膜依然保持著其偵測乙醇的能力。另外，使用此修飾電極來偵測市售含有乙醇的樣品做為探討，此生物感測器的穩定度及再現性也被詳細的研究。第三部份：以簡單的電化學方式製備酵素薄膜修飾電極，把多層奈米碳管 ( MWCNTs ) 掺雜胭脂紅酸 ( Carminic acid ) 改質成 CACNT ，再用電聚合方式將過氧化氫酶（catalase）沉積在 CACNT 修飾的玻璃碳電極上。以計時安培法 ( i-t ) 測定過氧化氫的電催化反應 ( pH = 7 PBS )，濃度線性範圍為1×10-5 到5.77×10-3 M。從 AFM 和 SEM 的結果可以清楚看出CAT / CACNT 和其他層薄膜的表面形貌。然而，分別加入1×10-4 M 的AA、DA 和 Glycerol 干擾物，而CAT / CACNT修飾膜不受干擾物質的影響，此薄膜依然保持著高選擇性偵測過氧化氫的能力。另外，使用此修飾電極來偵測市售含有過氧化氫的樣品做為分析，此生物感測器的穩定度及再現性也被詳細的探討。

關鍵字

4 4’-磺醯二苯胺 ； 二氧化鈦 ； 菸鹼醯胺核苷酸 ； 電催化 ； 光電催化 ； 胭脂紅酸 ； 多層奈米碳管 ； 乙醇去氫酶乙醇 ； 過氧化氫 ； 過氧化氫酶

並列摘要

Part I：We developed a novel poly (DDS) doped nano TiO2 composite film on indium tin oxide (ITO) electrode through electropolymerization technique. The electrocatalytic and photoelectrocatalytic studies for NADH oxidation was carried out at the composite film using cyclic voltammetry (CV) and amperometric i-t curve studies. CV results show that irradiation of the composite film surface for 5 min produced an enhanced electrocatalytic oxidation current for NADH which is higher than the electrocatalytic current observed at the composite film without irradiation. The composite film detects NADH in the linear concentration range from 5×10-8 to 1.2×10-7 M. We have characterized the prepared composite film through SEM, AFM and XRD studies. The SEM and AFM results confirm that the composite film has been formed on the ITO surface. XRD results show that the TiO2 NPS are crystalline and belongs to anatase phase. EIS and light induced EIS studies corroborates the electrochemical and photoelectrochemical behavior of different films investigated in this study.
Part II：Herein we report a novel amperometric ethanol sensor based on alcohol dehydrogenase immobilized onto poly-L-lysine (PLL) coated carminic acid (CA) functionalized multiwalled carbon nanotubes (MWCNTs). In the present study, we prepared a stable dispersion of MWCNTs using CA, anthraquinone dye as a dispersing agent. The prepared CA functionalized MWCNTs (CACNT) are extremely stable for several months without any precipitation. We have characterized the prepared CACNT and the different films through scanning electron microscopy (SEM), atomic force microscopy (AFM), UV–vis absorption spectroscopy and electrochemical impedance spectroscopy (EIS) studies. SEM and AFM results confirm that MWCNTs form a uniform stable suspension in CA aqueous solution. Both CACNT and the composite film containing CACNT exhibit characteristic UV–vis absorption absorption peak at 280 nm for CA which reveals that MWCNTs are functionalized with CA. The prepared stable CACNT dispersion was coated with poly-L-Lysine film on a glassy carbon electrode (GCE) and used for the immobilization of ADH through the electrostatic interactions between the negatively charged ADH (isoelectric point of ADH pI~6.8) and positively charged PLL film. The prepared ADH/PLL/CACNT composite film exhibits excellent electrocatalytic reponse towards 2.5 x 10-2 to 3.01 M ethanol. The proposed ADH/PLL/CACNT composite film was also successfully employed for the determination of ethanol from commercially available wine samples which shows the good practical applicability of this method
Part III：We report a novel amperometric H2O2 sensor based on catalase (CAT) immobilized at carminic acid functionalized multiwalled carbon nanotubes (CACNT) modified glassy carbon electrode. We successfully prepared a stable dispersion of MWCNTs in carminic acid aqueous solution which was extremely stable even after one month storage at room temperature. The prepared CACNT suspension was characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM) studies. The SEM and AFM results reveal that the prepared CACNT is well dispersed in CA aqueous solution. Further, SEM and AFM images of CANT/CAT composite film shows that CAT has been well immobilized at CACNT. UV–vis absorption spectroscopy results corroborate that the immobilized CAT retains its native structure and remains highly stable at CACNT matrix. Amperometric i-t curve results show that the composite film exhibits excellent electrocatalytic response to H2O2 in the linear concentration range from 1×10-5 M to 5.77×10-3 M. Furthermore, the composite film is highly selective towards H2O2 even in the presence of 0.1 mM of ascorbic acid, dopamine and uric acid. The composite film also successfully detects H2O2 from commercially available wash stain remover solution which shows its good practical applicability.

並列關鍵字

poly (DDS) ； TiO2 nano particles ； NADH ； electocatalytis ； photoelectrocatalysis ； carminic acid ； multiwall carbon nanotubes ； alcoholdehydrogenase ； ethanol ； catalase ； hydrogen peroxide

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