Department of Laboratory Medicine, Nanfang Hospital, Southern Medical University, 510515, Guangzhou, Guangdong Province, People's Republic of China.
Guangdong Engineering and Technology Research Center for Rapid Diagnostic Biosensors, Nanfang Hospital, Southern Medical University, 510515, Guangzhou, People's Republic of China.
Mikrochim Acta. 2020 Apr 4;187(5):259. doi: 10.1007/s00604-020-4205-z.
A fluorescent platform was developed for the determination and visualization of circulating tumor cells by a toehold-mediated bifunctional DNA nanomachine. In the presence of target tumor cells, the DNA nanomachine was activated. Multiple DNA products were formed, including dendritic DNA products and double-strand DNA products. Dendritic DNA products bound to their target cells for the visualization, while double-strand DNA products were released for the determination of tumor cells. At fluorescence excitation and emission wavelengths of 530 and 550 nm, this method could detect as low as 43 cells/mL (S/N = 3) with a linear range of 100 to 10,000 cells/mL. In clinical hydrothorax samples, this platform exhibited high reliability with a recovery of 93 to 116%. At the fluorescence excitation and emission wavelengths of 490 and 515 nm, the specificity and biocompatibility of this method were further verified by tumor cells imaging. Furthermore, the robustness of the toehold-mediated bifunctional DNA nanomachine was demonstrated by the specific gene mutation detection in single-cell analysis. Graphical abstract Schematic illustration of the fluorescent immunosensor for determination and imaging of circulating tumor cells. The method is based on aptamer-based recognition and toehold-mediated bifunctional DNA nanomachine.
一种荧光平台被开发出来，用于通过基于引发链置换的双功能 DNA 纳米机器来测定和可视化循环肿瘤细胞。在存在靶肿瘤细胞的情况下，DNA 纳米机器被激活。形成了多种 DNA 产物，包括树突状 DNA 产物和双链 DNA 产物。树突状 DNA 产物与靶细胞结合以进行可视化，而双链 DNA 产物则被释放以用于测定肿瘤细胞。在荧光激发和发射波长为 530 和 550nm 时，该方法可以检测低至 43 个/mL 的细胞（S/N=3），线性范围为 100 到 10,000 个/mL。在临床胸腔积液样本中，该平台的回收率为 93%至 116%，具有较高的可靠性。在荧光激发和发射波长为 490 和 515nm 时，通过肿瘤细胞成像进一步验证了该方法的特异性和生物相容性。此外，通过单细胞分析中的特定基因突变检测，证明了基于引发链置换的双功能 DNA 纳米机器的稳健性。
