Sun Liping, Zhong Yong, Gui Jie, Wang Xianwu, Zhuang Xiaorong, Weng Jian
Key Laboratory of Biomedical Engineering of Fujian Province, Research Center of Biomedical Engineering of Xiamen, Department of Biomaterials, College of Materials, Xiamen University.
Department of Neurology, The Affiliated Zhongshan Hospital of Xiamen University, Xiamen, People's Republic of China.
Int J Nanomedicine. 2018 Feb 8;13:843-856. doi: 10.2147/IJN.S152163. eCollection 2018.
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by progressive cognitive and memory impairment. It is the most common neurological disease that causes dementia. Soluble amyloid-beta oligomers (AβO) in blood or cerebrospinal fluid (CSF) are the pathogenic biomarker correlated with AD.
A simple electrochemical biosensor using graphene oxide/gold nanoparticles (GNPs) hydrogel electrode was developed in this study. Thiolated cellular prion protein (PrP) peptide probe was immobilized on GNPs of the hydrogel electrode to construct an AβO biosensor. Electrochemical impedance spectroscopy was utilized for AβO analysis.
The specific binding between AβO and PrP probes on the hydrogel electrode resulted in an increase in the electron-transfer resistance. The biosensor showed high specificity and sensitivity for AβO detection. It could selectively differentiate AβO from amyloid-beta (Aβ) monomers or fibrils. Meanwhile, it was highly sensitive to detect as low as 0.1 pM AβO in artificial CSF or blood plasma. The linear range for AβO detection is from 0.1 pM to 10 nM.
This biosensor could be used as a cost-effective tool for early diagnosis of AD due to its high electrochemical performance and bionic structure.
阿尔茨海默病（AD）是一种神经退行性疾病，其特征为进行性认知和记忆障碍。它是导致痴呆的最常见神经疾病。血液或脑脊液（CSF）中的可溶性淀粉样β寡聚体（AβO）是与AD相关的致病生物标志物。
本研究开发了一种使用氧化石墨烯/金纳米颗粒（GNPs）水凝胶电极的简单电化学生物传感器。将硫醇化细胞朊蛋白（PrP）肽探针固定在水凝胶电极的GNPs上，构建AβO生物传感器。利用电化学阻抗谱进行AβO分析。
水凝胶电极上AβO与PrP探针之间的特异性结合导致电子转移电阻增加。该生物传感器对AβO检测具有高特异性和高灵敏度。它能够选择性地将AβO与淀粉样β（Aβ）单体或原纤维区分开来。同时，它对人工脑脊液或血浆中低至0.1 pM的AβO检测高度敏感。AβO检测的线性范围为0.1 pM至10 nM。
由于其高电化学性能和仿生结构，该生物传感器可作为一种经济高效的工具用于AD的早期诊断。
