聚合型離子液體修飾電極於電化學分析的開發

The development of polymerized ionic liquid modified screen-printed carbon electrodes for electrochemical analysis

吳昇璜(Sheng-Huang Wu)

指導教授 ： 魏國佐

國立中正大學/理學院/化學暨生物化學系/碩士(2015年)

摘要

本研究是以聚合型離子液體為化學修飾網版印刷碳電極 ( SPCE )的平台之開發，室溫離子液體具有導電性、黏度大、極小的蒸氣壓及良好的熱穩定性，故可將其修飾在電極表面形成穩固的薄膜，成為離子液體化學修飾電極。本研究是以固定兩種可聚合之離子液體單體 ( [C4VIM][PF6] 和 [C9(VIM)2][PF6]2 ) 比例混合，使用液滴塗覆法 ( drop coating ) 與熱聚合的方式形成疏水性的聚合型離子液體薄膜，修飾在網版印刷碳電極表面。第一部份利用此聚合型離子液體修飾電極 (PIL-SPCE)，於循環伏安法 (Cyclic Voltammetry, CV) 掃描ascorbic acid (AA), dopamine (DA), 與 uric acid (UA)，成功得到三個分析物分離之氧化過電位，由於在 CV 圖中得到三個分離的氧化訊號，可利用方波伏安法 ( Square Wave Voltammetry, SWV ) 在高濃度ascorbic acid (AA) 與uric acid (UA) 水溶液環境中，偵測並定量dopamine (DA)，結果顯示此電極可於AA與UA存在下偵測 dopamine，且具有良好的選擇性與靈敏度。
第二部份延伸聚合型離子液體修飾電極 (PIL-SPCE) 的實用性，將銀奈米粒子與聚合型離子液體結合併修飾於電極，製成銀奈米粒子離子液體電極 (AgNPs-PIL-SPCE)，並應用於兩種不含發光基團之爆炸物 RDX (1,3,5-Trinitroperhydro-1,3,5-triazine) 與HMX (Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) 的分析與檢測。兩種爆炸物在 CV 圖中有明顯的還原訊號，顯示AgNPs-PIL-SPCE具有電催化RDX與HMX的效果；由於 PIL-SPCE 有良好的機械性質，可使用流動注射分析 (Flow injection analysis, FIA) 來進行RDX與HMX的定量分析，RDX與HMX 之線性範圍分別為 10-300 μM 與 30-500 μM；偵測極限分別為 7.40 μM 與 9.97 μM (S/N=3)。本研究顯示，Polymerized ionic liquid (PIL) 於電極表面型成一層電催化薄膜，可直接偵測樣品，或針對不同樣品，結合不同 mediator 進行電化學偵測，是提供一個化學修飾電極的平台，可增加SPCE的選擇性與實用性。

關鍵字

網版印刷電極 ； 離子液體

並列摘要

The goal of this study is to explore the use of polymerized ionic liquid as the platform of chemical modified screen-printed carbon electrodes for electroanalysis. Room temperature ionic liquids (RTILs) have many specific physicochemical properties, such as high ionic conductivity, high viscosity, negligible vapor pressure, and good thermal stability. Therefore, they can be modified onto the electrodes to form stable electric conductive media for electroanalysis. In this study, a polymerized ionic liquid was formed on the surface of a screen-printed carbon electrode (SPCE) by thermo polymerization of a drop-coated mixture of ionic liquid monomers. The electrode of a SPCE modified with polymerized ionic liquid (PIL-SPCE) exhibits electrocatalytic activity for the oxidation of ascorbic acid (AA), dopamine (DA), and uric acid (UA). With PIL-SPCE, three well-defined anodic peaks can be obtained. We employed square wave voltammetry to determine AA, DA, and UA simultaneously. The result showed that the PIL-SPCE has good sensitivity and selectivity for the detection of dopamine in the presence of high concentration of ascorbic acid and uric acid.
Furthermore, we used polymerized ionic liquids to immobilize Ag nanoparticles and form Ag nanoparticles containing composited electrode for electrochemical analysis of cyclic nitramine explosives, RDX and HMX. Due to the robustness of the electrode, we can use flow injection analysis for the determination of RDX and HMX. Linear calibration plots are in the range of 10-300 μM and 30-500 μM with the detection limit of 7.40 μM and 9.97 μM (S/N=3) for RDX and HMX, respectively. These results show that polymerized ionic liquid can be employed as a platform to create a thin-film catalytic medium for electrochemical analysis.

並列關鍵字

screen-printed electrode ； ionic liquid

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