Abstract：
Pharmaceutical pollution has received considerable attention because of the harmful effects of pharmaceutical compounds on human health, even in trace amounts. Amoxicillin is one of the frequently used antibiotics that was included in the list of emerging water pollutants. Therefore, a highly selective and rapid technique for amoxicillin detection is required. In this work, a new aptamer was selected for amoxicillin and utilized for the development of a label-free electrochemical aptasensor. Aptamer selection was performed using the systematic evolution of ligands by exponential enrichment. The selected aptamer showed good specificity against other antibiotics, including the structurally related antibiotics: ampicillin and ciprofloxacin. Among the selected aptamers, Amx3 exhibited the lowest dissociation constant value of 112.9 nM. An aptasensor was developed by immobilization of thiolated Amx3 aptamer onto gold screen-printed electrodes via self-assembly, which was characterized using cyclic voltammetry and electrochemical impedance spectroscopy. The detection was realized by monitoring the change in the differential pulse voltammetry peak current in the ferro/ferricyanide redox couple upon binding of the aptasensor to amoxicillin. The aptasensor showed very good sensitivity with an ultralow limit of detection of 0.097 nM. When the aptasensor was tested using actual spiked milk samples, excellent recovery percentages were observed. The label-free electrochemical aptasensor developed herein is a promising tool for the selective and sensitive detection of amoxicillin in environmental samples.
摘要：
由于药物化合物对人体健康的有害影响，药物污染已引起人们的广泛关注。即使是微量的。阿莫西林是经常使用的抗生素之一，被列入新出现的水污染物清单。因此,需要一种高度选择性和快速的阿莫西林检测技术。在这项工作中,为阿莫西林选择了一种新的适体，并用于开发无标记的电化学适体。通过指数富集使用配体的系统进化进行适体选择。选择的适体对其他抗生素表现出良好的特异性，包括结构相关的抗生素：氨苄青霉素和环丙沙星。在选定的适体中，Amx3表现出112.9nM的最低解离常数值。通过自组装将巯基化的Amx3适体固定到金丝网印刷电极上，开发了一种适体，用循环伏安法和电化学阻抗谱对其进行了表征。通过监测aptasensor与阿莫西林结合后，铁/铁氰化物氧化还原对中差分脉冲伏安峰值电流的变化来实现检测。aptasensor显示出非常好的灵敏度，超低的检测限为0.097nM。当使用实际加标牛奶样品测试aptasensor时，观察到优异的回收率。本文开发的无标记电化学传感器是用于环境样品中阿莫西林的选择性和灵敏检测的有前途的工具。
