Department of Anesthesiology, Affiliated Hospital of Shaanxi University of Traditional Chinese Medicine, Xianyang, Shaanxi, 712000, People's Republic of China.
Department of Anesthesiology, Xi'an GemFlower Changqing Hospital, Xi'an, Shaanxi, 710200, People's Republic of China.
Int J Nanomedicine. 2021 Mar 19;16:2311-2322. doi: 10.2147/IJN.S302396. eCollection 2021.
Alzheimer's disease (AD) is a neurodegenerative chronic disorder that causes dementia and problems in thinking, cognitive impairment and behavioral changes. Amyloid-beta (Aβ) is a peptide involved in AD progression, and a high level of Aβ is highly correlated with severe AD. Identifying and quantifying Aβ levels helps in the early treatment of AD and reduces the factors associated with AD.
This research introduced a dual probe detection system involving aptamers and antibodies to identify Aβ. Aptamers and antibodies were attached to the gold (Au) urchin and hybrid on the carbon nanohorn-modified surface. The nanohorn was immobilized on the sensor surface by using an amine linker, and then a Au urchin dual probe was immobilized.
This dual probe-modified surface enhanced the current flow during Aβ detection compared with the surface with antibody as the probe. This dual probe interacted with higher numbers of Aβ peptides and reached the detection limit at 10 fM with R=0.992. Furthermore, control experiments with nonimmune antibodies, complementary aptamer sequences and control proteins did not display the current responses, indicating the specific detection of Aβ.
Aβ-spiked artificial cerebrospinal fluid showed a similar response to current changes, confirming the selective identification of Aβ.
阿尔茨海默病（AD）是一种神经退行性慢性疾病，可导致痴呆和思维、认知障碍以及行为改变。淀粉样蛋白-β（Aβ）是参与 AD 进展的肽，高水平的 Aβ与严重的 AD 高度相关。鉴定和定量 Aβ水平有助于 AD 的早期治疗，并减少与 AD 相关的因素。
本研究引入了一种双探针检测系统，涉及适体和抗体来识别 Aβ。适体和抗体被连接到金（Au）刺球上，并在碳纳米角修饰的表面上杂交。纳米角通过胺接头固定在传感器表面上，然后固定 Au 刺球双探针。
与以抗体作为探针的表面相比，这种双探针修饰的表面增强了 Aβ检测过程中的电流流动。这种双探针与更多数量的 Aβ肽相互作用，在 10 fM 时达到检测限，R=0.992。此外，用非免疫抗体、互补适体序列和对照蛋白进行的对照实验没有显示出电流响应，表明可以特异性检测 Aβ。
含 Aβ的人工脑脊液显示出类似的电流变化响应，证实了 Aβ的选择性识别。
