以電流式生物感測器檢測食品中麩胺酸單納鹽之濃度

Application of an Amperometric Sensor for the Detection of Monosodium Glutamate

本研究使用自行產製之L－麩胺酸氧化酶，建立L－麩氨酸生物感測器，利用反應產生的過氧化氫於電極上產生的電流，來檢測L－麩氨酸濃度，其最低檢測濃度可達50nM，所需的檢測時間約3分鐘，其靈敏度可滿足檢測食品中麩胺酸單鈉鹽含量之需求，亦可滿足用來分析生體樣品中與老年癡呆等症狀有關的神經傳導物質L－麩胺酸之濃度。此感測器具有甚佳安定性，可於冷藏乾燥條件下貯存5個月而活性仍維持為在原來之80％以上，可在35℃下連續穩定操作10小時。

A highly sensitive and stable L-glutamate sensor was fabricated for the rapid detection of the monosodium glutamate. L-glutamate oxidase was immobilized in a polymeric matrix containing a photo-crosslinkable polymer. The sensor exhibited remarkable long-term stability in storage (five months in the dry dark state). The sensor response remained stable for ten hours even in a continuously stirred medium. This indicates a good operational stability of the enzymatic electrode and suggests this biosensor is suitable for multiple-use or continuous analysis. The enzyme electrode exhibited a linear calibration range in concentrations of monosodium glutamate (MSG) from 50 nM to 100μM, with a correlation coefficient of 0.997 (n= 10). The detection limit of MSG was 50 nM (S/N=3).