金-乙酰胆碱酯酶纳米复合物膜电化学检测有机磷农药

An electrochemical biosensing for the detection of organophosphorus pesticides based on a gold-acetylcholinesterase nanocomposite thin film

本文构建了一种基于界面法合成的金-乙酰胆碱酯酶（Au-AChE）纳米复合膜,并用于电化学检测有机磷农药.固定于电极表面的Au-AChE纳米复合膜中的AChE催化氯化乙酰胆碱（ATCl）水解生成硫代胆碱,硫代胆碱在特定电位下产生氧化峰电流.有机磷农药对AChE有抑制作用,当溶液中有机磷农药增多时,AChE催化ATCl水解生成硫代胆碱量减少,氧化峰电流下降.在最佳条件下,传感器用于甲胺磷检测的线性范围为0.005~5,5~100μg/mL,最低检出限为0.0011μg/mL,并显示出良好的稳定性与重现性,可用于实际样品中甲胺磷的检测.研究表明,界面法合成的金膜能有效固定AChE,并可拓展到其他生物分子的固定,以期构建不同的生物传感器.

An electrochemical biosensing for the detection of organophosphorus pesticides（OP） based on a gold-acetylcholinesterase（Au-AChE） nanocomposite thin film as an electrode platform which was prepared by an interface method was developed. The degree of inhibition of the AChE enzyme by OP compounds was determined by measuring the electrooxidation current of the thiocholine generated by the AChE catalyzed hydrolysis of acetylcholine chloride（ATCl）. In the presence of organophosphorus pesticides, the AChE is inhibited and its activity decreases. This resulted in a decrease of thiocholine concentration and as a result the current decreases. Under optimum conditions, the designed biosensor showed good stability and reproducibility with a low detection limit of 0.0011 μg/m L and a linear response ranging from 0.005 to 100 μg/m L, which was satisfactory for clinical sample detections. In this work, the synthesis of Au thin film combining AChE on the interface facilitates the Au-AChE nanocomposite＇s orderly arrangement and it provided a novel pathway for the immobilization of biomolecules.