Miniature Hierarchical DNA Hybridization Circuit for Amplified Multiplexed MicroRNA Imaging.

Accurate diagnosis requires the development of multiple-guaranteed DNA circuits. Nevertheless, for reliable multiplexed molecular imaging, existing DNA circuits are limited by poor cell-delivering homogeneity due to their cumbersome and dispersive reactants. Herein, we developed a compact-yet-efficient hierarchical DNA hybridization (HDH) circuit for in situ simultaneous analysis of multiple miRNAs, which could be further exploited for specifically discriminating cancer cells from normal ones. By integrating the traditional hybridization chain reaction and catalytic hairpin assembly reactants into two highly organized hairpins, the HDH circuit is fitted with condensed components and multiple response domains, thus permitting the programmable multiple microRNA-guaranteed sequential activations and the localized cascaded signal amplification. The synergistic multi-recognition and amplification features of the HDH circuit facilitate the magnified detection of multiplex endogenous miRNAs in living cells. The in vitro and cellular imaging experimental results revealed that the HDH circuit displayed a reliable sensing performance with high selective cell-identification capacity. We anticipate that this compact design can provide a powerful toolkit for accurate diagnostics and pathological evolution.