基于磁性介孔SiO_(2)免电极修饰电化学适配体传感器检测啶虫脒

A Modification-free Electrochemical Aptasensor Based on Magnetic Mesoporous SiO_(2) for Detection of Acetamiprid

基于氨基化磁性介孔SiO_(2)负载啶虫脒适配体、二茂铁-DNA互补链为探针,制备氨基化磁性介孔二氧化硅@纳米金-适配体-核酸互补链-二茂铁(NH_(2)-MMS@Au NPs-Apt-cDNA-Fc)磁性复合物,构建了免电极修饰的高灵敏电化学适配体传感器,用于快速检测啶虫脒。在0.1 mol/L的磷酸缓冲溶液(pH 7.4)中,以裸玻碳电极为工作电极,在最佳孵育时间下,以方波伏安法检测啶虫脒的线性范围为0.055 pmol/L~5.5 nmol/L,检出限为3.2 fmol/L(R_(SN)=3)。用于蔬菜中啶虫脒的检测,结果令人满意。该方法有效避免了繁琐的电极修饰和探针固定过程引起的系统误差,易于操作并且提高了检测的准确性,为高灵敏检测食品中的农残提供了一种新的、便捷的传感技术,具有较好的应用前景。

In this study,amine-functionalized magnetic mesoporous silica@gold nanoparticles-aptamer-complementary DNA-ferrocene complex(NH_(2)-MMS@Au NPs-Apt-cDNA-Fc)was prepared by using aminated magnetic mesoporous SiO_(2)supported acetamiprid aptamer and ferrocene-labeled complementary DNA(Fc-cDNA)as probes,and used to construct a highly sensitive electrochemical aptasensor with modification-free electrode for rapid detection of acetamiprid.In 0.1 mol/L phosphate buffered saline(PBS)solution(pH 7.4),using a bare glassy carbon electrode as working electrode,the linear range for acetamiprid detection by square wave voltammetry was 0.055 pmol/L–5.5 nmol/L at the optimal incubation time.The limit of detection was 3.2 fmol/L(R_(SN)=3).Satisfactory results were obtained for the detection of acetamiprid in vegetables.This method effectively avoids the systematic errors caused by the tedious electrode modification and probe fixation processes,is easy to operate,and has high accuracy.It provides a new and simply sensing technology for highly sensitive detection of pesticide residues in foods,and has a good application prospect.