Multiplex DNA Walking Machines for Lung Cancer-Associated miRNAs

Biomimetic DNA walking machines have gained great success in scrutinizing the microscopic world and sensitive biosensing of disease biomarkers. Despite superb achievements, the research on DNA walking machines for simultaneous detection of multiple analytes is still rare, while the design and realization of multiplexing are considered as an important bottleneck. The multiplex detection of biomarkers can not only improve the specificity of bioassays but also avoid the squander of valuable biological specimens. Herein, we reported multiplex three-dimensional (3D) DNA walking machines based on high-resolution inductively coupled plasma mass spectrometry (HR-ICPMS) for lung cancer-associated miRNA detection. In the presence of lung cancer-associated target miRNAs (miR-21, miR-141, and miR-125b), DNA walking machines were stimulated and operated to liberate a large number of lanthanide elements (Tb, Ho, and Tm), and then the signals were collected simultaneously by HR-ICPMS. The recovery test of target miRNAs in human serum and the simultaneous monitoring experiment of three miRNAs in human lung cancer cell line (A549) and normal cell line (HBE) specimens display satisfactory analysis capabilities for complex biological samples. Thanks to the vast potential of lanthanide tags and the modular design, the proposed bioassay might flexibly detect different miRNA combinations with corresponding sets of DNA walking machines to meet the requirements of various tasks.