Phase-transition-like behaviors of sequence-selective dynamic bonds

Sequence-selective dynamic bonds (SSDBs) are ubiquitous in nature and man-made systems as diverse as DNA, proteins, and synthetic sequence-defined oligomers. The specific and dynamic nature of this class of bonds enables encoded linkers to program the self-assembly of a broad range of building blocks. However, the possible collective behavior emerging from multiple SSDBs in programmable self-assembly remains elusive, due to experimental challenges. Here, we analyze the thermodynamic properties and kinetic pathways of SSDB hybridization through simulations supported by analytical theories, treating widely applicable cases of sequence-selective interactions. Our results reveal that the hybridization of SSDB linkers with certain rotational freedom can result in phase-transition-like behavior, which dictates the stability and the spontaneous transitions of typical states. In particular, there exists a metastable intermediate that plays a critical role in the thermally active hybridization facilitated by entropy, in contrast to normal dynamic bonds. We demonstrate that such a unique characteristic of thermodynamics causes stepwise kinetics of SSDB hybridization and hence anomalous diffusion of particles functionalized with SSDB linkers. Our work suggests that the presence of collective effect and phase-transition-like behavior may well be the crucial feature that guides larger scale ordering and dynamics in diverse systems of multiple SSDBs.