The authors demonstrate a simple and efficient method to speed up the DNA computing systems via photoswitchable phase separation. By iterative formation and dissolution of coacervate microdroplets in response to UV and blue light, the kinetics of basic strand displacement reactions and complex DNA neuron computation are accelerated up to fourfold.

DNA-based molecular computing has emerged as a promising alternative for performing sophisticated computational processes, holding the potential to advance the field of biosensing and clinical diagnosis. However, the majority of DNA computing systems rely exclusively on freely diffusing reactive molecules, making it intractable to scale up such circuits due to the low computation speed. Herein, the use of photoswitchable phase separation as a simple and efficient method to boost the speed of DNA computing systems is introduced. The acceleration arises from the utilization of coacervate microdroplets, formed by phase separation, as membrane-free compartments, which increase the effective local concentration of active DNA molecules. Photoswitchable phase separation demonstrates its ability to accelerate DNA computing across different circuit sizes, including basic DNA strand displacement reactions (≈4.3-fold) and complex DNA neuron computations (≈3-fold), without tuning of DNA sequences. It is envisioned that this powerful method could help realize high-efficiency molecular computing, paving the way for diverse applications.