Department of First Neurology, Baoding No.1 Central hospital, Baoding, Hebei 071000, China.
Endocrine laboratory, Baoding No.1 Central hospital, Baoding, Hebei 071000, China.
J Immunol Methods. 2021 Feb;489:112942. doi: 10.1016/j.jim.2020.112942. Epub 2020 Dec 14.
Highly sensitive and easy detection method for Alzheimer's disease (AD) with a suitable biomarker is mandatory for preventing the factors resulting from AD. This research reports a modified ELISA with graphene for the detection of AD biomarker amyloid beta (Aβ) oligomer. Gold nanoparticle (AuNP) conjugated aptamer was used as the capture probe and attached on ELISA-graphene oxide surface through the amine linker. Antibody was used as the detection molecule to reach the maximum detection of Aβ oligomer. Suitable level of APTMS (2%), size of AuNP (30 nm) and aptamer concentration (2 μM) were optimized. This sandwich pattern of aptamer-Aβ oligomer-antibody helps to reach the detection at 50 pM on the optimized ELISA surface and the control experiments in the absence of Aβ oligomer or anti-Aβ oligomer antibody did not show the significant optical detection at 492 nm, indicting the specific detection. Further, Aβ oligomer spiked artificial cerebrospinal fluid did not interfere the detection of Aβ oligomer, confirming the selective detection. This new and modified ELISA surface helps to reach the lower detection of Aβ oligomer and diagnose AD.
对于预防由阿尔茨海默病（AD）引起的各种因素来说，一种灵敏且易于检测 AD 的方法，以及一个合适的生物标志物是非常必要的。本研究报告了一种用石墨烯改良的 ELISA 方法，用于检测 AD 生物标志物淀粉样β（Aβ）寡聚体。金纳米粒子（AuNP）偶联的适体被用作捕获探针，并通过胺连接子附着在 ELISA-氧化石墨烯表面上。抗体被用作检测分子，以达到 Aβ寡聚体的最大检测效果。优化了合适的 APTMS（2%）、AuNP 尺寸（30nm）和适体浓度（2μM）。适体-Aβ寡聚体-抗体的三明治模式有助于在优化的 ELISA 表面上达到 50pM 的检测，并且在不存在 Aβ寡聚体或抗 Aβ寡聚体抗体的对照实验中，在 492nm 处没有显示出显著的光学检测，表明具有特异性检测。此外，人工脑脊液中添加的 Aβ寡聚体不会干扰 Aβ寡聚体的检测，证实了其选择性检测。这种新的改良的 ELISA 表面有助于达到对 Aβ寡聚体的更低检测限，并用于 AD 的诊断。
