AbstractTwo 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 abstractSchematic 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.

中文翻译：

---

基于适体与金纳米粒子相互作用的两种比色氨苄西林传感方案

摘要描述了两种氨苄青霉素（AMP）适体传感器。测定策略包括使用经 (a) 硫醇化适体 (T-Apt) 和 (b) 非硫醇化聚腺嘌呤适体 (polyA Apt) 修饰的金纳米粒子 (AuNPs)。AuNPs 和适配体在添加 AMP 之前进行相互作用。T-Apt 和 polyA Apt 通过不同的机制吸附在 AuNPs 上。吸附的适体能够结合靶标，同时防止非特异性相互作用。AMP 的存在和不存在会产生显着不同的吸光度（在 520 和 680 nm 处测量）。即使存在类似化学结构的物种，该测定也可以选择性地识别 AMP。基于 T-Apt 的检测在 1–600 nM AMP 浓度范围内具有线性响应，检测限为 0.1 nM。polyA Apt 检测的相应数据为 1–400 nM 和 0.49 nM。图形摘要使用两种抗氨苄青霉素适体和金纳米颗粒进行氨苄青霉素检测的比色适体传感器的示意图。聚二烯丙基二甲基氯化铵 (PDDA) 作为聚集剂。