Ravan Hadi, Norouzi Akram, Sanadgol Nima, Hosseinzadeh Elyas
Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran.
Department of Clinical Biochemistry, School of Medicine, Kerman University of Medical Sciences, Kerman, Iran.
Mikrochim Acta. 2020 Jun 17;187(7):392. doi: 10.1007/s00604-020-04368-7.
According to aptamer-mediated hairpin DNA cascade amplifier and gold nanoparticles aggregation, an optical platform for cancer cells determination has been proposed. High-affinity chimeric aptamers were used for cancer cell detection and also as an initiator for beginning hairpin assembly to construct three-way junction (3WJ) nanostructures. These three hairpins were modified at 3' ends with biotin. In the presence of target cell, chimeric aptamer binds to its ligand on cell surface and initiates 3WJ nanostructures formation. These 3WJ nanostructures interact with streptavidin-modified gold nanoparticles (AuNPs) via non-covalent biotin-streptavidin interactions and create a crossover lattice of nanoparticles. This event leads to AuNPs aggregation and red-shifting. The results were confirmed by gel electrophoresis and UV-visible spectrophotometry. The dynamic range of this assay is 25 to 10 cells with a detection limit of 10 cells which is respectively 9 and 4 times more significant than the sensitivity of AuNP-based approaches without amplification and enzyme-mediated signal amplification. Graphical abstract.
基于适体介导的发夹DNA级联放大器和金纳米颗粒聚集，提出了一种用于癌细胞检测的光学平台。高亲和力嵌合适体用于癌细胞检测，并作为启动发夹组装以构建三向连接（3WJ）纳米结构的引发剂。这三个发夹在3'端用生物素修饰。在靶细胞存在的情况下，嵌合适体与其在细胞表面的配体结合并启动3WJ纳米结构的形成。这些3WJ纳米结构通过非共价生物素-链霉亲和素相互作用与链霉亲和素修饰的金纳米颗粒（AuNPs）相互作用，并形成纳米颗粒的交叉晶格。这一事件导致AuNPs聚集和红移。结果通过凝胶电泳和紫外可见分光光度法得到证实。该检测方法的动态范围为25至10个细胞，检测限为10个细胞，分别比无扩增和酶介导信号放大的基于AuNP的方法的灵敏度高9倍和4倍。图形摘要。
