Solid-state Luminescence Intermittency Unlocks in situ Label-free Super-Resolution Imaging of Supramolecular Fiber Growth

Understanding how supramolecular structures grow requires imaging methods that combine nanometer-scale resolution with real-time operation under native conditions, yet super-resolution microscopy typically relies on extrinsic dyes that may perturb assembly pathways. Here, we show that supramolecular fibers from a saccharide-derived benzaldehyde (SachCHO) exhibit both Solid-state Luminescence Enhancement (SLE) and Solid-state Luminescence Intermittency (SLI), enabling label-free stochastic optical reconstruction microscopy (STORM). Crucially, the SLI is not imparted by external labelling but is fundamentally linked to the assembly process itself, localizing at structural defects within the fibers via a defect-mediated redox-blinking mechanism. Using SLI-STORM, we visualize fiber self-assembly with ~25 nm resolution and identify these defects as hotspots of heterogeneous growth, revealing intermittent elongation and non-classical kinetic growth regimes. Analogous behavior in amyloid fibrils suggests this phenomenon is general. By leveraging the material's own photo-physics/chemistry, SLI-STORM transforms the assembling structure into its own dynamic reporter, offering a minimally invasive strategy to probe growth and defect formation in both synthetic and biological supramolecular materials.