Acceleration of DNA reactions on the algae-based microrobots

DNA reactions on solid surfaces often suffer from low efficiency due to limited mass transfer and slow reaction kinetics, which greatly limits their biomedical applications. Here, we report a strategy to construct dynamic DNA biointerfaces based on moveable algal microrobots (AMs), whose autonomous motion-generated micro-hydrodynamics profoundly affects interfacial DNA reactions. After immobilizing DNA strands on the AMs, we uncover that the swimming speed of these microrobots is positively correlated with the kinetics of different DNA reactions from simple hybridization to complex enzymatic/nonenzymatic amplification reactions. This "motion-enhanced" effect mainly stems from the convection and mixing generated around the swimming cells, which greatly improve mass transfer velocity, thereby reducing hybridization times to minutes and enhance reaction efficiency. As a result, this feature is demonstrated to be useful in achieving ultrafast molecular recognition, ultrasensitive nucleic acid detection, and autonomous cell assembly in complex biological media. Our work provides a paradigm shift for overcoming the reaction efficiency bottleneck of DNA interface and paves a new avenue for designing intelligent bio-hybrid systems.