Self-Regulating Colloidal Co-Assemblies That Accelerate Their Own Destruction via Chemo-Structural Feedback.

Biological self-assemblies self- and cross-regulate each other via chemical reaction networks (CRNs) and feedback. Although artificial transient self-assemblies have been realized via activation/deactivation CRNs, the transient structures themselves do mostly not engage in the CRN. We introduce a rational design approach for chemo-structural feedback, and present a transient colloidal co-assembly system, where the formed co-assemblies accelerate their destruction autonomously. We achieve this by immobilizing enzymes of a deactivating acid-producing enzymatic cascade on pH-switchable microgels that can form co-assemblies at high pH. Since the enzyme partners are immobilized on individual microgels, the co-assembled state brings them close enough for enhanced acid generation. The amplified deactivator production (acid) leads to an almost two-fold reduction in the lifetime of the transiently formed pH-state. Our study thus introduces versatile mechanisms for chemo-structural feedback.