Department of Chemistry, Khorramabad Branch, Islamic Azad University, Khorramabad, Iran.
Mikrochim Acta. 2019 Jan 7;186(2):56. doi: 10.1007/s00604-018-3123-9.
The authors introduce a new kind of aptameric imprinted polymer for sensing tetracycline (TET), thereby combining the unique features of aptamer-based and molecularly imprinted polymer based recognition. The dual recognition scheme results in sensing capabilities that are superior to those of the aptamer alone, or of a conventional molecularly imprinted polymer alone. In the first step, the aptamer-TET complex was immobilized on the surface of a glassy carbon electrode (GCE) decorated with gold nanoparticles. Dopamine was then electropolymerized on the surface of the modified GCE to entrap the aptamer-TET complex. TET was then extracted with an ethanol-acetic acid mixture (95:5) in order to create void cavities. On exposure to TET, the cavities are filled with TET again, and this leads to a retardment of the interfacial charge transfer of the redox probe hexacyanoferrate, typically measured at a peak voltage of 0.22 V vs. Ag/AgCl. The assay detects TET in the concentration ranges from 0.5-100 pM and from 1-1000 nM with a very low limit of detection of 144 fM. Its superior selectivity and affinity make this assay a viable tool as demonstrated for the successful analysis of TET in spiked milk samples. Graphical abstract Schematic representation of a glassy carbon electrode (GCE) modified with gold nanoparticles (AuNPs) and coated with an aptamer-imprinted polymer (MIP).
作者介绍了一种新型的适体印迹聚合物，用于检测四环素（TET），从而结合了基于适体和基于分子印迹聚合物的识别的独特特征。这种双重识别方案导致的传感能力优于单独的适体或常规的分子印迹聚合物。在第一步中，将适体-TET 复合物固定在修饰有金纳米粒子的玻碳电极（GCE）表面上。然后在修饰后的 GCE 表面上电聚合多巴胺以捕获适体-TET 复合物。然后用乙醇-乙酸混合物（95:5）提取 TET，以形成空穴。暴露于 TET 时，空腔再次充满 TET，这导致氧化还原探针六氰合铁的界面电荷转移延迟，通常在 0.22 V 对 Ag/AgCl 的峰电压下进行测量。该测定法可检测 0.5-100 pM 和 1-1000 nM 范围内的 TET，检测限非常低，为 144 fM。其优越的选择性和亲和力使其成为一种可行的工具，如成功分析加标牛奶样品中的 TET 所示。
