State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, China.
Analyst. 2018 Sep 24;143(19):4585-4591. doi: 10.1039/c8an00132d.
β-Secretase (BACE1) is an important drug target in the treatment of Alzheimer's disease (AD). Therefore, sensitive detection of BACE1 is essential for AD treatment and drug discovery. In this work, a facile and sensitive fluorescence biosensing platform was developed for BACE1 detection. This sensing platform was constituted based on the interaction between a WS2 nanosheet and a peptide sequence. In the absence of BACE1, a FAM-labeled peptide substrate could be adsorbed on the surface of the WS2 nanosheet, thereby quenching its fluorescence. However, in the presence of BACE1, the hydrolysis of the peptide substrate by BACE1 triggers could occur with the subsequent release of short FAM-linked peptide fragments which could not be adsorbed on the surface of the WS2 nanosheet. This resulted in weak fluorescence quenching, thus restoring the fluorescence signal. By measuring the change in the fluorescence of the FAM-labeled peptide substrate, the fluorescence sensing platform based on the WS2 nanosheet could monitor BACE1. The proposed WS2 nanosheet-based platform exhibited excellent specificity and high sensitivity with a detection limit of 66 pM for BACE1. Importantly, we also demonstrated that this platform was suitable for the screening of BACE1 inhibitors. The proposed sensing platform not only provides a novel strategy for the BACE1 assay but also offers a potential tool for screening drugs.
β-分泌酶（BACE1）是治疗阿尔茨海默病（AD）的重要药物靶点。因此，BACE1 的敏感检测对于 AD 的治疗和药物发现至关重要。在这项工作中，开发了一种用于 BACE1 检测的简便、灵敏的荧光生物传感平台。该传感平台基于 WS2 纳米片与肽序列的相互作用构成。在没有 BACE1 的情况下，FAM 标记的肽底物可以被吸附在 WS2 纳米片的表面，从而猝灭其荧光。然而，在存在 BACE1 的情况下，BACE1 触发的肽底物的水解可以发生，随后释放出不能被吸附在 WS2 纳米片表面的短 FAM 连接的肽片段。这导致荧光猝灭减弱，从而恢复荧光信号。通过测量 FAM 标记的肽底物的荧光变化，可以基于 WS2 纳米片监测 BACE1。所提出的基于 WS2 纳米片的平台表现出优异的特异性和高灵敏度，对 BACE1 的检测限为 66 pM。重要的是，我们还证明了该平台适用于 BACE1 抑制剂的筛选。该传感平台不仅为 BACE1 测定提供了一种新策略，也为药物筛选提供了一种潜在工具。
