Dynamic Macro- and Microgels Driven by Adenosine Triphosphate-Fueled Competitive Host-Guest Interaction

Abstract

Supramolecular host-guest systems are generally at thermodynamic equilibrium states or in kinetically trapped states. Herein, we demonstrate the concept of a chemical fuel-driven competitive host-guest assembly featuring autonomous dynamics. The enabling keyprinciple is todesigna chemical fuel thatpossesses a high binding affinity to defeat the guest transiently, undergoes conversion to a waste product, and exhibit weak binding affinity in order to recover the original host-guest pair. By following this principle, adenosine triphosphate (ATP; chemical fuel and competitive guest), biguanidine-functionalized β-cyclodextrin (β- CD; host), and an adamantine species (ADA; guest) have been engineered to construct dynamic adaptive macrogels or chemo-mechanochromicmicrogels with programmed time domains.Our reportedmethodology provides temporal control over the host-guest process, representing a conceptually new tool for the design of living supramolecular materials.