以黏粒修飾電極法探討層面電荷對多巴胺電化學反應的影響

Clay-modified Electrodes for Use to Study the Effect of Layer Charge on Electrochemical Behavior of Dopamine

朱家瑩(Chia-Ying Chu) ； 陳鴻基(Horng-Ji Chen) ； 曾志明(Jyh-Myng Zen)

《土壤與環境》 18卷1&2期 (2015/12) Pp. 1-17

摘要

酚類化合物普遍存在於土壤中，黏土礦物對酚類化合物的催化聚合與轉化反應常是土壤腐植質先驅物形成的關鍵，其對土壤的形成、物理化性質、生物性質及土壤肥力之影響扮演重要的角色。本論文研究目的以不同黏土礦物修飾網版印刷碳電極(SPCE)搭配電化學方法對多巴胺等進行電化學分析，探討多巴胺與黏土礦物層面電荷間的交互作用關係。試驗結果指出，六種黏粒修飾預氧化網版印刷碳電極(SPCE*)所偵測的電流量都明顯大於六種黏粒修飾網版印刷碳電極(SPCE)，且預氧化處理使電極表面的官能基與多巴胺產生氫鍵，使得對多巴胺偵測到的R_2還原波峰[由O_2Φ(CH_2)_2NH_2還原成．O(OH)Φ(CH_2)_2NH_2]及O_2氧化波峰[由．O(OH)Φ(CH_2)_2NH_2氧化成O_2Φ(CH_2)_2NH_2]的波峰電流量都明顯增大很多。鄰苯二酚的存在會使六種黏粒修飾預氧化電極對多巴胺偵測到的R_2、O_2氧化還原波峰電流量增大的量大於R_1、O_1氧化還原波峰電流量增大的量。由於黏土礦物的同構代換會影響礦物結晶構造內的氧化還原狀態，影響電子在黏土礦物結構中的Fe^(2+/3+)及以-OH官能基質子化為橋梁的轉移速率，進而影響多巴胺在不同結晶構造與層面電荷之黏土礦物修飾電極表面所表現的電化學行為。利用黏粒修飾電極搭配循環伏安法的電化學分析能夠簡便迅速探討酚類化合物與黏土礦物層面電荷間的交互作用。

關鍵字

黏土礦物 ； 多巴胺 ； 電化學分析

並列摘要

Phenolic compounds are common in soil and their catalytic polymerization and transformation are key to the formation of humus precursors. The process plays a significant role in the pedogenesis, physical, chemical and biological properties and soil fertility. This study investigates the electrochemical behavior of dopamine with different clay-modified screen-printed carbon electrodes (SPCE) to understand the interaction between dopamine and layer charge of clay minerals. The results indicate that the peak currents of dopamine at six different clay-modified preanodized screen-printed carbon electrodes (SPCE*) were more than those at bare clay-modified SPCEs. Preanodization significantly increase the peak currents of R_2 [reduction of O_2Φ(CH_2)_2NH_2 to ．O(OH)Φ(CH_2)_2NH_2] and O_2 [oxidation of ．O(OH)Φ(CH_2)_2NH_2 to O_2Φ(CH_2)_2NH_2] due to preanodized the functional groups generated during the preanodization process. The peak currents of R_2 and O_2 for co-exist solution were higher than those of R_1 and O_1 observed at the six clay-modified SPCE*s. The different electrochemical behavior of dopamine was affected by different crystal structure and layer charge of clay minerals due to the redox states of crystal structure were affected by isomorphic substitution of clay minerals that affected electronic transferability in structural Fe^(2+/3+) and protonated -OH group. The interaction between phenolic compounds and layer charge of clay minerals can be easily elucidated based on this easy technique and method.

並列關鍵字

Clayminerals ； Dopamine ； Electroanalysis