De Novo-Designed Landmine Warfare Strategy Luminophore For Super-Resolution Imaging Reveal Onoo- Evolution In Living Cells

Due to the non-specific staining of existing fluorescent markers, which mask many positive signal acquisition, the nanoscale imaging of a small bioactive molecule such as peroxynitrite (ONOO-), however, is currently unavailable. Herein, we propose a "landmine warfare strategy", probe L-1 evenly "buries" in the cellular matrix as a "landmine" (no fluorescence), when ONOO- "stepped on" the probe L-l, causing the "landmine explosion" to release fluorophore, thus capturing ONOO- particles, under structured illumination microscopy (SIM). We found that probe L-1 shows high sensitivity and selectivity for ONOO- in vivo, with a detection limit as low as 85.7 nM in vitro. Using this "landmine warfare strategy", the ONOO- formation, up to a resolution of 100 nm, bounding to the mitochondrial cristae was revealed for the first time. Under lipopolysaccharide induction, the state of ONOO- labeled by L-1 changes from a single particle to an aggregated state. Thus, this system represents an attractive strategy for the imaging the structure and tracking of functional bioactive small molecules by resolving the issue of non-specific staining in living cells under SIM.