电极表面等温酶循环DNA分子机器放大信号电致化学发光检测DNA和肿瘤细胞

In this paper, an ingenious strategy of an electrode surface-related "one-pot" cascade DNA auto-machine cooperated with enhanced is proposed for target electrochemiluminescence (ECL) detection. Target DNA hybridized with template DNA as a primer activated the DNA machine through the polymerization-cleavage-displacement reactions in the presence of polymerase, nicking endonuclease and dNTPs fuels. The tedious operation of separation procedure is circumvented by the step of hybridization chain reaction (HCR) attached on the electrode surface, offering the advantages of operation-simple and time-saving. Notably, as compared to traditional fluororescent signal of DNA machine in which high nonspecific background could be induced by excess molecular beacon or fluorescent dye, in the present study nonspecific background can be markedly reduced by introducing directly HCR on electrode surface. Overall, the system exhibits high sensitivity and specificity with the detection limit as low as 0.2 fM. Besides, based on the specificity between the aptamer and its ligand, the method was designed for cancer cell analysis as low as 15 cells, holding a great promise for clinical applications.