He Guangli, Zhou Yue, Li Mifang, Guo Yanzhen, Yin Hang, Yang Baocheng, Zhang Shouren, Liu Yibiao
Henan Key Laboratory of Nanocomposites and Applications, Institute of Nanostructured Functional Materials, Huanghe Science and Technology College, Zhengzhou, China.
Shenzhen Longgang Central Hospital (The Second Affiliated Hospital of the Chinese University of Hong Kong, Shenzhen, China.
Front Bioeng Biotechnol. 2021 Nov 16;9:777344. doi: 10.3389/fbioe.2021.777344. eCollection 2021.
Amyloid-β protein (Aβ) is an important biomarker and plays a key role in the early stage of Alzheimer's disease (AD). Here, an ultrasensitive photoelectrochemical (PEC) sensor based on ZnO@polydopamine/Au nanocomposites was constructed for quantitative detection of Aβ. In this sensing system, the ZnO nanorod array decorated with PDA films and gold nanoparticles (Au NPs) have excellent visible-light activity. The PDA film was used as a sensitizer for charge separation, and it also was used for antibody binding. Moreover, Au NPs were loaded on the surface of PDA film by deposition, which further improved the charge transfer efficiency and the PEC activity in visible light due to the localized surface plasmon resonance effect of Au NPs. Therefore, in ZnO@polydopamine/Au nanocomposites, a significantly enhanced photocurrent response was obtained on this photoelectrode, which provides a good and reliable signal for early detection of AD. Under the optimized conditions, the PEC immunosensor displayed a wide linear range from 1 pg/mL to 100 ng/mL and a low detection limit of 0.26 pg/mL. In addition, this PEC immunosensor also presented good selectivity, stability, and reproducibility. This work may provide a promising point-of-care testing method toward advanced PEC immunoassays for AD biomarkers.
淀粉样β蛋白（Aβ）是一种重要的生物标志物，在阿尔茨海默病（AD）的早期阶段发挥着关键作用。在此，构建了一种基于ZnO@聚多巴胺/Au纳米复合材料的超灵敏光电化学（PEC）传感器，用于定量检测Aβ。在该传感系统中，装饰有聚多巴胺（PDA）薄膜和金纳米颗粒（Au NPs）的ZnO纳米棒阵列具有优异的可见光活性。PDA薄膜用作电荷分离的敏化剂，还用于抗体结合。此外，通过沉积将Au NPs负载在PDA薄膜表面，由于Au NPs的局域表面等离子体共振效应，进一步提高了电荷转移效率和可见光下的PEC活性。因此，在ZnO@聚多巴胺/Au纳米复合材料中，该光电极上获得了显著增强的光电流响应，为AD的早期检测提供了良好且可靠的信号。在优化条件下，PEC免疫传感器的线性范围为1 pg/mL至100 ng/mL，检测限低至0.26 pg/mL。此外，该PEC免疫传感器还具有良好的选择性、稳定性和重现性。这项工作可能为AD生物标志物的先进PEC免疫分析提供一种有前景的即时检测方法。
