有機磷與氨基甲酸鹽農藥生物感測器之開發研究

A Study on the Development of a Biosensor for the Detection of Organophosphorus and Carbamate Pesticides

張博智(Bo-Chih Chang) ； 蔡文琦(Wen-Chi Tsai)

《臺灣農業化學與食品科學》 43卷4期 (2005/08) Pp. 253-260

https://doi.org/10.6578/TJACFS.2005.033

摘要

本研究的目的在建立一個電化學的生物感測器，以應用於有機磷劑及氨基甲酸鹽農藥之檢測。以市售自動鉛筆心作為工作電極，於其上固定乙醯膽鹼酯酶(acetylcholinesterase; AchE)及膽鹼氧化酶(cholinc oxidase; ChOx)以作為生物感測元件。首先比較數種酵素固定化方法，結果顯示將工作電極置於10%硝酸溶液中，施以+2.2V電壓三分鐘，使電極表面產生羥基(-COOH)，再藉由carbodiimide活化後，與乙醯膽鹼酯酶及膽鹼氧化酶之酵素液反應後，可以達到最佳的固定化效果。如此所製備之酵素電極，在乙醯膽鹼濃度為0.5-12.5mM之間呈線性。比較以50%及5%的有機溶劑進行農藥萃取時，對酵素電極活性的影響。結果顯示以5%丙酮溶液作為農藥的萃取溶劑時對酵素電極的活性影響最小。酵素電極對氨基甲酸鹽農藥加保伏之檢測範圍在0.05-lmg/L之間可得一良好線性(R^2=0.93)，其偵測極限可達0.01mg/L。同樣的，對有機磷劑農藥二氯松的檢測範圍在0.05-lmg/L之間可得到良好線性(R^2=0.94)，偵測極限可達0.01mg/L。應用於實際樣品小白菜的回收率在97-120%之間，且與傳統的生化法之間有良好的相關性。

關鍵字

酵素電極 ； 農藥 ； 生物感測器 ； 抑制作用

並列摘要

The aim of this study was to develop an electrochemical biosensor for the detection of organophosphorus and carbamate pesticides. In this study, we used pencil leads as the working electrodes. The biosensing elements, acetylcholinesterase and choline oxidase, were immobilized upon the working electrodes. Several immobilization techniques were investigated, and the covalent binding via surface carboxyl groups gave the best performance. The generation of carboxyl groups on the electrode surface was achieved by placing the working electrode in 10% nitric acid solution at +2.2 V for three minutes. This was followed by carbodiimide activation and then incubation with cholinesterase and choline oxidase to form covalent bonds. The prepared enzyme electrode showed linear response to acetylcholine in the range of 0.5-12.5 mM. The effect of 50% and 5% solvent systems on the activities of enzyme electrodes were examined. Results showed that a 5% acetone solution had the least unfavorable effect on enzyme activity. When the enzyme electrode was employed in carbofuran detection, linearity was observed between 0.05 and 1 mg/L (R^2=0.93). The detection limit was 0.01 mg/L. The response of the enzyme electrode to dichlorovos was also linear between 0.05 and 1 mg/L (R^2=0.94), and the detection limit was 0.01 mg/L. Chinese mustard spiked at 0.5 and 1.0 mg/L of carbofuran, and dichlorovos exhibited a range of 97-120% for recovery of the pesticides, a result was in agreement with the traditional biochemical method.

並列關鍵字

Enzyme electrode ； Pesticides ； Biosensor ； Inhibition