Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and Device, School of Chemistry and Chemical Engineering, Southeast University, Nanjing, 211189, China.
Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou, 450001, China.
Anal Chim Acta. 2023 Mar 1;1244:340857. doi: 10.1016/j.aca.2023.340857. Epub 2023 Jan 18.
β-amyloid peptide (Aβ) aggregates are regarded as a typical neuropathology hallmark for the diagnosis of Alzheimer's disease (AD). Aβ aggregates include soluble oligomers (AβO) and insoluble fibrils (AβF). Both of them can simultaneously bind to two different kinds of its aptamer (Apt1 and Apt2). As a mass-sensitive sensing platform, quartz crystal microbalance (QCM) converts changes in mass on the Au chip surface into frequency shift. Here, a dual-aptamer assisted Aβ aggregates assay was developed. Taking AβO detection as an example, Apt2 was modified on the surface of Au chip by Au-S bond. Subsequently, the solution consisted of AβO and gold nanoparticles-Apt1 (AuNPs-Apt1) were injected into the QCM chamber. As a result, AβO was specifically recognized and captured by Apt2. AuNPs-Apt1 were also combined on the surface of the Au chip because AβO can simultaneously bind to Apt1. Then, a significant frequency shift occurred because of the large weight of AuNPs. Similarly, this procedure can be used to detect AβF. This QCM biosensor was able to detect AβO with a range of 0.2-10 pM with a detection limit of 0.11 pM, while the linear range for AβF was 0.1-10 pM with a detection limit of 0.02 pM. This QCM biosensor was simple and highly sensitive, which provided a new method for Aβ aggregates detection.
β-淀粉样肽（Aβ）聚集体被认为是阿尔茨海默病（AD）诊断的典型神经病理学标志物。Aβ 聚集体包括可溶性寡聚物（AβO）和不溶性纤维（AβF）。它们都可以同时与两种不同类型的适体（Apt1 和 Apt2）结合。作为一种质量敏感的传感平台，石英晶体微天平（QCM）将金芯片表面质量的变化转化为频率位移。在这里，开发了一种双适体辅助的 Aβ 聚集体检测方法。以 AβO 检测为例，通过 Au-S 键将 Apt2 修饰在 Au 芯片表面。随后，将含有 AβO 和金纳米粒子-Apt1（AuNPs-Apt1）的溶液注入到 QCM 腔室中。结果，AβO 被 Apt2 特异性识别和捕获。由于 AuNPs-Apt1 的重量很大，AuNPs-Apt1 也结合在 Au 芯片表面。然后，由于 AuNPs 的重量很大，会发生显著的频率位移。同样，这个过程可以用来检测 AβF。这种 QCM 生物传感器能够检测 0.2-10 pM 范围内的 AβO，检测限为 0.11 pM，而 AβF 的线性范围为 0.1-10 pM，检测限为 0.02 pM。这种 QCM 生物传感器简单且高度灵敏，为 Aβ 聚集体检测提供了一种新方法。
