Kinetically programmed pathway-dependent autonomous reversibility in biomimetic self-assembly of nanoparticles

Autonomous reversibility is fundamental to many natural systems, enabling the formation of dynamic and adaptive assemblies without continuous external intervention. Replicating autonomous behavior in artificial systems remains challenging, as it demands a kinetic imbalance in the self-assembly process driven by chemically triggered dynamic interactions. Here, we demonstrate pathway-dependent autonomous reversibility in a bio-nano hybrid system composed of adenosine triphosphate (ATP) and gold nanoparticles (AuNPs), with hexokinase (HK) as an enzymatic disassembling trigger. The electrostatic interaction between oppositely charged AuNPs and ATP drives co-assembly, while HK-mediated dephosphorylation of ATP to ADP weakens these interactions, inducing rapid disassembly. Autonomous reversibility is achieved via two distinct pathways. In pathway I, excess HK promotes autonomous disassembly, with ATP addition triggering the transient assembly. Conversely, in pathway II, an excess of ATP maintains autonomous assembly, with transient disassembly driven by HK-mediated dephosphorylation. Thus, using the same constituent components under distinct conditions, we demonstrate both transient assembly and transient disassembly within a single system. Interestingly, the autonomous assembly and disassembly pathways determine the nature of the self-assembled state - either a precipitate or a plasmonically active controlled aggregate is formed. The lifetime of these transient states is tuned from minutes to hours by balancing the competing kinetics of ATP and HK triggers, offering a versatile platform for temporal control in applications such as transient catalysis and other time-programmed functions.