硼酸酯修飾電極-製備與探討

Abstract

硼酸衍生物，如3-aminophenylboronic acid (簡稱APBA)，因可與醇類化合物進行反應而形成硼酸酯，本論文因而以之製備具生化應用潛力的蒽醌修飾電極。我們首先利用偶氮修飾法將APBA修飾於電極如導電ITO玻璃或石墨片(HOPG)，再將醌類化合物還原成為羥基化合物，使之與硼酸鍵結形成硼酸酯而穩定吸附於電極表面，其中所修飾的醌類化合物有pyrroquinoline quinone (簡稱PQQ )、9,10-phenanthrenequinone（簡稱CCQ）以及1,10-phenanthroline-5,6-dione（簡稱NNQ）。對於這些電極，我們分別以電化學技巧與光譜分析法探討其性質與應用潛力，如對銅離子的偵測。實驗結果顯示PQQ修飾電極對Cu2+離子具有特殊親合力，因此可藉以偵測Cu2+離子，偵測極限約為500*10-6 M。

Boronic acid derivatives like 3-aminophenylboronic acid (denoted APBA) can form stable compounds with a variety of alcohols, such as dopamine and fructose. In view of the potential in this aspect, we devoted effort to fabricating chemically modified electrodes based on APBA and biochemically important electron mediator, such as pyrroquinoline quinone (PQQ) and many others like 9,10-phenanthrenequinone (CCQ), and 1,10-phenanthroline-5,6-dione (NNQ). According to electrochemical, spectroscopic and surface analyses, PQQ can be converted into PQQH2 chemically or electrochemically, and thereby forming boronic acid ester with APBA on ITO or graphite surface. The surface-bound PQQ was characterized, showing affinity to Cu2+ ion. Benefiting from this merit, Cu2+ ion could thus be detected with a level as low as 500*10-6 M.