Lu Yi, Liu Juewen, Mazumdar Debapriya
Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, IL, USA.
Methods Mol Biol. 2009;535:223-39. doi: 10.1007/978-1-59745-557-2_14.
Aptamers are single-stranded nucleic acids or peptides that can bind target molecules with high affinity and specificity. The conformation of an aptamer usually changes upon binding to its target analyte, and this property has been used in a wide variety of sensing applications, including detections based on fluorescence, electrochemistry, mass, or color change. Because native nucleic acids do not possess signaling moieties required for most detection methods, aptamer sensors usually involve labeling of external signaling groups. Among the many kinds of labels, inorganic nanoparticles are emerging as highly attractive candidates because some of their unique properties. Here, we describe protocols for the preparation of aptamer-linked gold nanoparticles (AuNPs) that undergo fast disassembly into red dispersed nanoparticles upon binding of target analytes. This method has been proven to be generally applicable for colorimetric sensing of a broad range of analytes. The sample protocols have also been successfully applied to quantum dots and magnetic nanoparticles. Finally, to increase the user friendliness of the method, the sensors have been converted into simple dipstick tests using lateral flow devices.
适体是能够以高亲和力和特异性结合靶分子的单链核酸或肽。适体与靶分析物结合后，其构象通常会发生变化，这一特性已被广泛应用于各种传感应用中，包括基于荧光、电化学、质量或颜色变化的检测。由于天然核酸不具备大多数检测方法所需的信号部分，适体传感器通常涉及外部信号基团的标记。在众多类型的标记中，无机纳米颗粒因其一些独特性质而成为极具吸引力的候选者。在此，我们描述了制备适体连接金纳米颗粒（AuNP）的方案，该金纳米颗粒在与靶分析物结合后会迅速分解为红色分散的纳米颗粒。该方法已被证明普遍适用于多种分析物的比色传感。示例方案也已成功应用于量子点和磁性纳米颗粒。最后，为提高该方法的用户友好性，已使用侧向流动装置将传感器转化为简单的试纸条测试。
