Targeted Drug Delivery Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Pharmaceutical Biotechnology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
Research Institute of Sciences and New Technology, Mashhad, Iran.
Biosens Bioelectron. 2019 May 15;133:230-235. doi: 10.1016/j.bios.2019.03.044. Epub 2019 Mar 22.
Herein, an electrochemical aptasensor is described for detection of ampicillin (Ampi). The sensing strategy is based on the application of a ladder-shaped DNA structure as a multi-layer physical block on the surface of gold electrode. Attributing to the electrostatic repulsion and physical prevention of the ladder-shaped DNA structure, ultrasensitive detection of Ampi was achieved with a detection limit as low as 1 pM. In the presence of Ampi, the ladder-shaped DNA structure is disassembled and detached from the electrode surface. This leads to the high access of [Fe(CN)] as a redox indicator to the electrode surface and a strong redox peak. The aptasensor response for Ampi detection was in the linear range from 7 pM to 100 nM with the detection limit of 1 pM. The presented analytical strategy showed its application in detecting Ampi in the spiked milk samples with satisfactory performance. This work can be easily expanded for different targets by alternating the corresponding aptamers.
本文描述了一种用于检测氨苄西林（Ampi）的电化学生物传感器。该传感策略基于梯型 DNA 结构作为多层物理阻断层应用于金电极表面。由于梯型 DNA 结构的静电排斥和物理阻碍作用，实现了对 Ampi 的超灵敏检测，检测限低至 1 pM。在 Ampi 的存在下，梯型 DNA 结构被拆开并从电极表面脱离。这导致[Fe(CN)]作为氧化还原指示剂高度进入电极表面并产生强氧化还原峰。该适体传感器对 Ampi 的检测响应在 7 pM 至 100 nM 的线性范围内，检测限为 1 pM。所提出的分析策略在检测加标牛奶样品中的 Ampi 方面表现出了令人满意的性能。通过交替相应的适体，这项工作可以很容易地扩展到不同的目标。
