Endogenous Enzyme-Powered DNA Nanomotor Operating in Living Cells for microRNA Imaging.

Accurate and specific imaging of low-abundance microRNA (miRNA) in living cells is extremely important for disease diagnosis and monitoring of disease progression. DNA nanomotors have shown great potential for imaging molecules of interest in living cells. However, inappropriate driving forces and complex design and operation procedures have hindered their further application. Here, we proposed an endogenous enzyme-powered DNA nanomotor (EEPDN), which employs an endogenous APE1 enzyme as fuel to execute repetitive cycles of motion for miRNA imaging in living cells. The whole motor system is constructed based on gold nanoparticles without other auxiliary additives. Due to the high efficiency of APE1, this EEPDN system has achieved highly sensitive miRNA imaging in living cells within 1.5 h. This strategy was also successfully used to differentiate the expression of specific miRNA between tumor cells and normal cells, demonstrating a high tumor cell selectivity. This strategy can promote the development of novel nanomotors and is expected to be a perfect intracellular molecular imaging tool for biological and medical applications.