Reversible and spatiotemporal control of colloidal structure formation

Tuning colloidal structure formation is a powerful approach to building functional materials, as a wide range of optical and viscoelastic properties can be accessed by the choice of individual building blocks and their interactions. Precise control is achieved by DNA specificity, depletion forces, or geometric constraints and results in a variety of complex structures. Due to the lack of control and reversibility of the interactions, an autonomous oscillating system on a mesoscale without external driving was not feasible until now. Here, we show that tunable DNA reaction circuits controlling linker strand concentrations can drive the dynamic and fully reversible assembly of DNA-functionalized micron-sized particles. The versatility of this approach is demonstrated by programming colloidal interactions in sequential and spatial order to obtain an oscillatory structure formation process on a mesoscopic scale. The experimental results represent an approach for the development of active materials by using DNA reaction networks to scale up the dynamic control of colloidal self-organization. The self-assembly of colloidal particles can be applied to create new structures and materials in the framework of systems chemistry. The authors demonstrate the realization of autonomous oscillating structure formation on the meso-scale, relevant for systems relying on DNA interactions.

Automated summary

By utilizing DNA specificity, depletion forces, and geometric constraints for precise control, the dynamic and fully reversible assembly of DNA-functionalized particles was achieved, demonstrating autonomous oscillating structure formation on the meso-scale.