Self-Propelled Magnetic Micromotor-Functionalized DNA Tile System for Autonomous Capture of Circulating Tumor Cells in Clinical Diagnostics

Abstract

Circulating tumor cells (CTCs) carry intact tumor molecular information, making them invaluable for personalized cancer monitoring. However, conventional capture methods, relying on passive diffusion, suffer from low efficiency due to insufficient collision frequency, severely limiting clinical utility. Herein, a magnetic micromotor-functionalized DNA-array hunter (MMDA hunter) is developed by integrating enzyme-propelled micromotors, magnetic nanoparticles, and nucleic acid aptamers into distinct functional partitions of a DNA tile self-assembly structure. This design ensured independent and compatible running of autonomous propulsion, targeted recognition, and magnetic enrichment, enabling efficient capture and subsequent identification of CTCs in clinical blood samples. The autonomous motion of the MMDA hunter is powered by O2 bubbles generated through the dual enzymatic cascade reactions of glucose oxidase and catalase under physiological glucose conditions. Compared to static Fe3O4 arrays (without micromotors), the MMDA hunter shows more than 2-fold improvement in capture efficiency. Meanwhile, it achieved superb precision, simple operation, rapid response, high biocompatibility, excellent stability, and superior specificity for CTC enrichment. This method provides a reliable tool for tumor diagnosis in multiple clinical application scenarios, even in primary medical care, simultaneously offering a clever solution for the bottleneck of functional-module interference in multifunctional nanomaterials.