基于环状核酸适体的 Ara h1 快速检测

为了能精准、快速检测出样品中的花生过敏源 Ara h1, 文章设计了一种基于环状核酸适体和磁性氧化石墨烯(magnetic graphene oxide, MGO)平台的无标记快速检测花生过敏原 Ara h1 的荧光传感器。特异性靶向 Ara h1 的环状核酸适体通过 $ \pi-\pi $ 堆积吸附在 MGO 上, 当样品中含有 Ara h1 时, 环状核酸适体与 Ara h1 结合形成复合物, 进而从 MGO 表面解吸附; 磁性分离去除 MGO, 再通过加热使 Ara h1 变性脱离其环状核酸适体, 此时环状核酸适体可以进一步作为滚环扩增(rolling circle amplification, RCA)的模板进行 RCA 反应, 加入 Sybr Gold 核酸染料即可产生荧光信号。该荧光传感器具有很好的特异性和灵敏度, 检测限低至 $ 0.02 \mu mol/L $, 检测线性范围为 $ 0.02 \sim 1.70 \mu mol/L $。该荧光传感器可用于实际样品中 Ara h1 的快速检测, 且操作简单、无需化学修饰, 在食物过敏原检测中有良好的应用前景。

In this paper, a fluorescent biosensor based on circular aptamer and magnetic graphene oxide (MGO) platform was constructed for the rapid and accurate label-free detection of peanut allergen protein Ara h1 in the samples. Circular aptamer specifically targeting Ara h1 was adsorbed onto MGO by $ \pi-\pi $ stacking. When Ara h1 presented in the samples, the circular aptamer bound to Ara h1 to form a complex, which in turn desorbed from the MGO surface. MGO was then removed by magnetic separation. The Ara h1-circular aptamer complex was denatured by heating to detach the circular aptamer, which could then be further used as a template for rolling circle amplification (RCA). Finally, the fluorescent signals could be generated by adding Sybr Gold nucleic acid dye. The fluorescent biosensor has excellent specificity and sensitivity, with a detection limit as low as 0.02 $ \mu $mol/L and a linear range of 0.02–1.70 $ \mu $mol/L. The biosensor can be used for the rapid detection of Ara h1 in real samples, which is simple to operate and does not require chemical modification, holding great potential for food allergen detection.