共電聚合羧酸化導電高分子電極之電化學與表面化學特性研究

Abstract

在生物感測器中的傳感器部分，導電高分子扮演了轉換離子與電子的重要角色。但在實際應用層面上，導電高分子與生物分子間常受限於無法有效固定，以及無法長時間應用於高pH值的環境中。為實踐導電高分子能夠同時固定生物分子以及提升電化學穩定性，將其官能基化為一重要議題。本論文將從提升共電聚合材料羧酸化程度，以及確認羧酸化導電高分子於中性環境之電化學活性。因此，我們導入兩大類的羧酸化材料（高分子酸及羧酸化奈米碳材）利用簡單溶液混合及共電聚合方法，製備出具有羧酸根的導電高分子複合材料。本篇論文探討使用兩種導電高分子polyaniline (PANI), polypyrrole (PPy)與兩大類羧酸化材料進行共電聚合，並分析其電化學特性及其表面化學特性。從FT-IR結果顯示PANI和PPy能和羧酸化材料進行共電聚合。在相同電鍍電量下PANI混摻Poly(acrylic acid)的組別中發現，加入超過25 mg/ml的PAA，會改變PANI的纖維結構，而PPy則是呈現出花椰菜般的緻密團簇結構。PANI-A 50之組別有最高的氧化還原峰電流，PPy-Gr有最好的贗電容穩定性，其贗電容衰退率只有13.59%。而在接觸角分析中可觀察出薄膜表面親疏水性與PAA混摻濃度有關，PAA濃度越高薄膜表面越親水。利用共電聚合法製備之羧酸化導電高分子其表面羧酸根數量可達1.06 ± 0.08 × 1017/cm2。適體固定化分析結果顯示羧酸化導電高分子表面可以固定3.62×1013 molecules/cm2。結果顯示，發現在不同的導電高分子中加入不同羧酸化材料會產生不一樣的羧酸化程度及電化學特徵，因此可以透過選擇不同的羧酸化導電高分子材料，以進行不同的生物與電化學相關實驗。

In the part of the transducer, the conducting polymer plays an important role in converting ions and electrons. However, in practical applications, biomolecules are often limited by ineffectively immobilized on the conducting polymers and cannot be used for a long time in high pH environments. In order to attain the conducting polymers capable of simultaneously immobilizing biomolecules and improving the electrochemical stability. The functionalization of conducting polymer is an important issue. This study will increase the degree of carboxylation of co-electropolymerized materials and confirm the electroactivity of carboxylated conducting polymers in a neutral environment. Therefore, we use two categories of carboxylated materials (high molecular weight and carboxylated carbon nanomaterials). And using simple solution mixing and co-electropolymerization methods to prepare carboxylated conducting polymer composites. From FT-IR results, PANI and PPy were successfully co-electropolymerized with carboxylated materials. In the group of PANI, it was found that the adding more than 25 mg/ml of PAA will change the fiber structure of PANI. And the PPy composites showed a dense cauliflower-like cluster structure. The PANI-A 50 group has the highest redox peak current, PPy-Gr has the best pseudo capacitance stability, and its pseudo capacitance decrease rate is only 13.59%. It can be observed that the hydrophobicity of the film surface is related to the concentration of PAA mixed. When the higher the PAA concentration was added into conducting polymers, the surface of the film will more hydrophilic. The amount of carboxyl group on the surface of carboxylated conducting polymers prepared by co-electropolymerization can reach 1.06 ± 0.08 × 1017/cm2. Aptamer immobilization analysis results showed that the carboxylated conducting polymers surface can be fixed 3.62×1013 molecules/cm2. The results show that the addition of different carboxylated materials to different conducting polymers will achieve in different degrees of carboxylation and electrochemical characteristics. Therefore, different carboxylated conducting polymer materials can be selected to perform different biological and electrochemical processes.