電活性中孔洞奈米金複合材料的製備與電化學感測之應用研究

Preparation and Electrochemical sensor Application of Electroactive Mesoporous Gold-Organosilica Nanocomposite Materials

徐柏軒(PO-HSUAN HSU)

指導教授 ： 葉瑞銘

中原大學/理學院/化學研究所/碩士(2013年)

https://doi.org/10.6840/CYCU.2013.00147

摘要

本論文成功製備出電活性中孔洞奈米複合材料（Electroactive mesoporous materials organosilica nanocomposites；EMON）與電活性中孔洞奈米金複合材料（Electroactive mesoporous gold-organosilica nanocomposites；EMGON），以此材料作為感測器偵測維生素C（Ascorbic Acid）分析物的感測能力。 第一部分是先利用氧化偶合合成穩定之苯胺五聚體（Aniline Pentamer；AP）電活性寡聚物與苯胺五聚體有機矽先驅物（TESPIC-AP）。接著將苯胺五聚體有機矽先驅物與Tetraethoxysilane（TEOS）進行溶膠-凝膠共縮合（Co- Condensation）方式，以有機小分子葡萄糖（D-glucose）作為成孔劑（Template），形成有機-無機混成之電活性中孔洞奈米複合材料（EMON）。複合電活性和無機矽氧化物的穩定中孔洞結構，結合電活性之氧化還原能力與中孔洞結構之高表面積的特性。主以電化學方式研究其EMON材料修飾碳糊電極（Carbon-paste electrode；CPE）偵測其維生素C（AA）之感測能力，發現修飾5 wt%電活性官能基的中孔洞奈米複合材料（EMON05）電極感測能力最好，比未修飾的碳糊電極在應答電流測試則提升3.3倍。 第二部分是進一步把感測維生素C（AA）能力最佳的電活性中孔洞奈米複合材料（EMON05），使其中具備氧化還原能力之苯胺五聚體做為還原劑與四氯金酸一步法（One pot）快速且簡便的形成奈米金，成為電活性中孔洞奈米金複合材料（EMGON），並通過改變四氯金酸溶液的濃度變化成功控制奈米金的粒徑大小，其最佳化條件為以1 mM四氯金酸形成的奈米金混摻（Blend）電活性中孔洞奈米金複合材料（EMGON-1），能有效藉由奈米金之電子傳導能力大幅提升維生素C（AA）感測能力，在應答電流測試其感測能力EMGON-1修飾電極各別比修飾EMON05的電極及未修飾的碳糊電極的應答電流測試則分別提升6.3倍和21倍，並且擁有良好的靈敏度，選擇性與穩定性。

關鍵字

非界面活性劑 ； 溶膠-凝膠 ； 中孔洞材料 ； 電活性特性 ； 感測器 ； 維生素C ； 奈米金

並列摘要

Electroactive mesoporous materials organosilica nanocomposites（EMON）and electroactive mesoporous gold-organosilica nanocomposites（EMGON）were successfully preparation in this work and were applied for ascorbic acid（AA）sensing.
First, the silsesquioxane precursor（TESPIC-AP）was prepared from the emeraldine base of aniline pentamer（AP）using a one-step coupling reaction. EMONs was synthesized by the co-condensation of tetraethoxysilane（TEOS）with silsesquioxane precursor（TESPIC-AP）in the presence of glucose structure-directing agents. The proportion of aniline pentamers（AP）as an electroactive segment which controlled the redox ability and influenced the degree of electrochemical activity and sensitivity of the nanocomposites toward AA. It is good sensing capability for EMON05, which have high surface area and good redox ability. The sensitivity of EMON05-modified carbon-paste electrode（CPE）was 3.3-fold higher than that of the bare CPE.
Second, EMGONs was successfully prepared by one-pot synthesis in HAuCl4 aqueous solution. Gold nanoparticles（AuNPs）were selectively reduced on an AP segment in an EMON05 matrix, which acted as a reductant as well as a provider of a large surface area to absorb and react with chloroaurate anions（AuCl4−）. Gold particle size can be controlled by the varying concentration of HAuCl4, and distributed AuNPs with controllable size were fabricated for EMGON. EMGON-1 modified CPE which was optimal AuNPs size enhanced the anodic oxidation of AA. A sensor constructed from EMGON-1 modified CPE demonstrated 21-fold and 6.3-fold higher electrocatalytic activity toward the oxidation of AA compared to those constructed using bare CPE and EMON05 modified CPE. The high surface area of EMGON-1 modified CPE exhibited a good electrochemical response toward AA at a low oxidative potential with good sensitivity, selectivity and stability.

並列關鍵字

Nonsurfactant ； Sol-gel ； Mesoporous ； Sensor ； Ascorbic Acid ； Gold ； Electroactive

參考文獻

1. 翁暢健, 中原大學化學系博士學位論文, 民95.

2. H. M. Ebelmen, 1846, 16, 129.

3. T. Graham, J. Chem. Soc., 1864, 17, 318-327.

4. H. Dislich, Glastechn. Ber., 1971, 44, 1.

5. Z. Alothman, Materials, 2012, 5, 2874-2902.