CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Key Laboratory of Biological Effects of Nanomaterials and Nanosafety, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China.
State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing, 100084, China.
Adv Mater. 2017 Aug;29(30). doi: 10.1002/adma.201700057. Epub 2017 Jun 12.
Alzheimer's disease (AD) is the most common form of dementia characterized by progressive cognitive decline. Current diagnosis of AD is based on symptoms, neuropsychological tests, and neuroimaging, and is usually evident years after the pathological process. Early assessment at the preclinical or prodromal stage is in a great demand since treatment after the onset can hardly stop or reverse the disease progress. However, early diagnosis of AD is challenging due to the lack of reliable noninvasive approaches. Here, an antibody-mimetic self-assembling peptoid nanosheet containing surface-exposed Aβ42-recognizing loops is constructed, and a label-free sensor for the detection of AD serum is developed. The loop-displaying peptoid nanosheet is demonstrated to have high affinity to serum Aβ42, and to be able to identify AD sera with high sensitivity. The dense distribution of molecular recognition loops on the robust peptoid nanosheet scaffold not only mimics the architecture of antibodies, but also reduces the nonspecific binding in detecting multicomponent samples. This antibody-mimetic 2D material holds great potential toward the blood-based diagnosis of AD, and meanwhile provides novel insights into the antibody alternative engineering and the universal application in biological and chemical sensors.
阿尔茨海默病（AD）是最常见的痴呆症形式，其特征是进行性认知能力下降。目前 AD 的诊断基于症状、神经心理学测试和神经影像学，通常在病理过程发生多年后才明显。由于发病后治疗几乎无法阻止或逆转疾病进展，因此对临床前或前驱期的早期评估有很大的需求。然而，由于缺乏可靠的非侵入性方法，AD 的早期诊断具有挑战性。在这里，构建了一种含有表面暴露的 Aβ42 识别环的抗体模拟自组装肽纳米片，并开发了用于检测 AD 血清的无标记传感器。结果表明，具有分子识别环的肽纳米片对血清 Aβ42 具有高亲和力，并能够以高灵敏度识别 AD 血清。在坚固的肽纳米片支架上密集分布的分子识别环不仅模拟了抗体的结构，而且减少了在检测多组分样品时的非特异性结合。这种抗体模拟的 2D 材料在基于血液的 AD 诊断方面具有很大的潜力，同时为抗体替代工程和在生物和化学传感器中的通用应用提供了新的见解。
