Department of Chemistry, Faculty of Science, University of Kurdistan, P. O. Box 416, Sanandaj, Iran.
Mikrochim Acta. 2019 Jul 1;186(7):485. doi: 10.1007/s00604-019-3524-4.
Two kinds of aptasensors for ampicillin (AMP) are described. The assay strategies include the use of gold nanoparticles (AuNPs) that were modified with (a) a thiolated aptamer (T-Apt), and (b) a non-thiolated polyadenine aptamer (polyA Apt). The AuNPs and the aptamers were brought to interaction prior to addition of AMP. T-Apt and polyA Apt are adsorbed on the AuNPs by different mechanisms. The adsorbed aptamer was able to bind the target while preventing non-specific interactions. Remarkably different optical absorbances (measured at 520 and 680 nm) are produced the absence and presence of AMP. The assay can selectively recognize AMP even in the presence of species of similar chemical structure. The T-Apt based assay has a linear response in the 1-600 nM AMP concentration range and a 0.1 nM limit of detection. The respective data for the polyA Apt assay are 1-400 nM and 0.49 nM. Graphical abstract Schematic presentation of the colorimetric aptasensor for ampicillin detection using two kinds of anti-ampicillin aptamers and gold nanoparticles. Polydiallyldimethylammonium chloride (PDDA) acts as aggregation agent.
两种氨苄青霉素（AMP）适体传感器被描述。该分析策略包括使用（a）巯基化适体（T-Apt）和（b）非巯基化多腺嘌呤适体（polyA Apt）修饰的金纳米粒子（AuNPs）。在添加 AMP 之前，将 AuNPs 和适体进行相互作用。T-Apt 和 polyA Apt 通过不同的机制被吸附在 AuNPs 上。被吸附的适体能结合靶标，同时阻止非特异性相互作用。在 AMP 的存在和不存在下，产生了显著不同的光吸收（在 520 和 680nm 处测量）。该测定法即使在具有相似化学结构的物质存在下也能选择性地识别 AMP。基于 T-Apt 的测定法在 1-600 nM AMP 浓度范围内具有线性响应，检测限为 0.1 nM。polyA Apt 测定法的相应数据为 1-400 nM 和 0.49 nM。
