Double-enzymes-mediated Fe2+/Fe3+ conversion as magnetic relaxation switch for pesticide residues sensing
Double-enzymes-mediated Fe2+/Fe3+ conversion as magnetic relaxation switch for pesticide residues sensing
复制标题
双酶介导的 Fe2/Fe3 转化作为农药残留传感的磁弛豫开关
DOI：
10.1016/j.jhazmat.2020.123619
复制
发表时间：
2021
影响因子：
13.6
通讯作者：
Chen Yiping
中科院分区：
文献类型：
--
作者：
Wu Long;Zhou Min;Liu Chen;Chen Xiaoqiang;Chen Yiping
发展一种新的快速、准确的农药残留检测方法是一个巨大的挑战。本工作以乙酰胆碱酯酶(AChE)和胆碱氧化酶(CHO)为基础，探索了一种双酶介导的Fe2+/Fe3+转换磁弛豫开关法测定乙酰胺磷残留量。在双酶反应中，乙酰胆碱可催化氯化乙酰胆碱生成胆碱，胆碱再被氯化胆碱催化生成甜菜碱和过氧化氢。根据酶抑制原理，乙酰胺磷的存在会使AChE活性失活，从而导致H_2O_2的产生减少。其中以Fe2+、ACh、AChE和CHO为反应底物进行了优化。在反应体系中，与H_2O_2介导的Fe~(2+)变化有关的横向弛豫时间(T_2)可以反映乙酰胺磷，这是一种进一步发展的酶级联扩增方法。该方法的线性范围为0.0 1∼10 0 0μg m L−1(R2=0.99)，检出限为2.6 6 ng m L−1(S/N=3，n=3)，比传统的酶抑制法(0.89μg m L−1)提高335倍。该方法可以实现扑虫菊酯的“一步混合”检测，是复杂样品中农药残留监测的一种很有前途的分析工具。
It is a great challenge to develop a newly rapid and accurate detection method for pesticide residues. In this work, based on acetylcholinesterase (AChE) and choline oxidase (CHO), a double-enzymes-mediated Fe2+/Fe3+conversion as magnetic relaxation switch was explored for the measurement of acetamiprid residue. In the double-enzymes reactions, acetylcholine chloride (ACh) can be catalyzed to produce choline by AChE, which is successively hydrolyzed to betaine and hydrogen peroxide (H2O2) by CHO. According to the enzyme inhibition principle, AChE activity will be inactivated in the presence of acetamiprid, thus leading to the less production of H2O2. Wherein, Fe2+, ACh, AChE and CHO were optimized as the reaction substrates. In the reaction system, acetamiprid can be reflected by the transverse relaxation time (T2) that related with H2O2mediated Fe2+variations, which was further developed as an enzyme cascade amplification method. The detection linear range is 0.01∼1000 μg mL−1(R2= 0.99), and the limit of detection (LOD) is 2.66 ng mL−1(S/N = 3, n = 3), behaving a 335-fold improvement in LOD than that of traditional enzyme inhibition method (0.89 μg mL−1). This method can realize “one-step mixing” detection of acetamiprid, which makes it a promising analytical tool for monitoring pesticide residue in complicated samples.