基于还原氧化石墨烯-聚苯胺/纳米金复合纳米材料的阻抗型电化学适配体传感器检测啶虫脒

An Impedimetric Aptamer Sensor Based on Reduced Graphene Oxide-Polyaniline/Gold Nanoparticle Nanocomposite for the Detection of Acetamiprid

基于纳米金(Aunanoparticles,AuNPs)/还原氧化石墨烯(reduced graphene oxide,rGO)-聚苯胺(polyaniline,PANi)复合材料制备一种高灵敏、高选择性的啶虫脒(acetamiprid,ACE)电化学适配体传感器(6-巯基-1-己醇(6-mercapto-1-hexanol,MCH)/Apt/AuNPs/rGO-PANi)。采用透射电镜、X射线衍射和扫描电镜/能谱等多种技术对所合成的纳米材料及电极的修饰界面进行了表征,确证了形貌及结构。使用电化学技术研究不同电极的电化学性能,发现AuNPs/rGO-PANi复合材料修饰电极具有较大的电化学活性面积和优异的电子传输能力,可为适配体的固定及电化学检测ACE提供一个理想的平台。在最优条件下,MCH/Apt/AuNPs/rGO-PANi对ACE检测的线性范围为1.0~100000.0 ng/L,检出限为0.15 ng/L(信噪比=3)。100倍的常见共存农药分子不会对ACE的检测产生明显干扰,将该适配体传感器用于青瓜和红薯叶样品检测,回收率为94.5%~98.5%,结果的准确性也得到了液相色谱-质谱法的验证。

In this study,a highly sensitive and selective electrochemical aptamer sensor(6-mercapto-1-hexanol(MCH)/Apt/AuNPs/rGO-PANi)for acetamiprid(ACE)was prepared based on Au nanocomposites(AuNPs)/reduced graphene oxide(rGO)-polyaniline(PANi).The morphology and structure of the synthesized nanomaterial and the interface of different electrodes were characterized by transmission electron microscopy(TEM),X-ray diffraction(XRD)and scanning electron microscopy(SEM)/energy dispersive X-ray spectrometry(EDX).The electrochemical properties of different electrodes were studied by cyclic voltammetry and electrochemical impedance spectroscopy,and it was found that the AuNPs/rGOPANi modified electrode showed a large electrochemical active area and excellent electrochemical properties,which could provide an ideal platform for aptamer fixation and electrochemical sensing of ACE.Under optimal conditions,the linear range of MCH/Apt/AuNPs/rGO-PANi for ACE detection was 1.0–100000.0 ng/L,and the detection limit was 0.15 ng/L at a signal-to-noise(RSN)of 3.A 100-fold excess of common co-existing pesticides did not significantly interfere with the detection of ACE.The prepared aptamer sensor was applied to the detection of cucumbers and sweet potato leaves with recoveries ranging from 94.5%to 98.5%.The accuracy of the developed method was verified by liquid chromatography-mass spectrometry(LC-MS).