双适体阻抗传感器检测生活用水中磺胺二甲氧嘧啶残留量

Double-aptamer-based impedance sensor for the determination of sulfadimethoxine residue in domestic water

构建了磺胺二甲氧嘧啶(SMZ)双适体阻抗型传感器。采用分子模拟(MD)方法揭示了适体与SMZ的结合模式,借助电化学测试技术确认并优化了传感过程与影响参数,系统考察了传感器的分析性能。结果表明,双适体组合方式相比单一适体具有更多活性位点,利于产生更高阻抗值而改善方法灵敏度。4种适体组合方式以inv-D-5T-SMZ结合最稳定。将方法用于实际自来水样品检测,线性范围为0.01~10.0 nmol/L,检出限为3.4 pmol/L;方法平均加标回收率在77.0%~85.4%之间,相对标准偏差(RSD)均<20%;全部检测过程不超过1 h。

A sulfadimethoxine(SMZ)double-aptamer-based impedance sensor was fabricated.The molecular dynamic(MD) simulation method was applied to reveal the binding mode of aptamer to SMZ.The electrochemical testing technology was used to confirm the sensing response process and optimize its response parameters,and the analytical performance of the sensor was also systematically investigated.The research results demonstrated that the double-aptamer had more active sites compared with the single-aptamer,which was helpful to produce higher resistance value and improve method sensitivity.The inv-D-5T-SMZ was the most stable among 4 docking ways of complex.When the method was used for the determination of practical tap water,the linear range and the detection limit were confirmed to be 0.01-10.0 nmol/L and 3.4 pmol/L,respectively.The average spiked recoveries of method were within the range of 77.0%-85.4% with RSD<20%.The whole analysis process could be finished in 1 h.