Oxidation-driven synthetic molecular networks enable dynamic assembly and fluorescence modulation in living cells

Systems chemistry explores emergent properties from interacting molecular networks, although extending these systems into biologically relevant environments remains challenging. Here, we report a synthetic molecular network that functions dynamically inside living cells by responding autonomously to oxidative stimuli. The network is built from dithiol precursors that undergo oxidation-driven macrocyclization and co-assemble with an aggregation-induced emission luminogen to form fluorescent nanostructures selectively under oxidative conditions. This process is reversible, allowing repeated cycles of fluorescence modulation. By exploiting intracellular oxidation as a stimulus, the system links systems chemistry with biological complexity and enables real-time monitoring of cellular redox dynamics through fluorescence. The fluctuations in signal directly reflect oxidative levels in living cells, providing a tool for tracking redox states. Our work demonstrates adaptive molecular self-assembly in a biological context and opens opportunities for redox bioimaging, diagnostics, and therapeutics regulated by cellular oxidative environments.