Super-resolved Optical Mapping of Reactive Sulfur-Vacancies in Two-Dimensional Transition Metal Dichalcogenides

Transition metal dichalcogenides (TMDs) represent a class of semiconducting two-dimensional (2D) materials with exciting properties. In particular, defects in 2D-TMDs and their molecular interactions the environment can crucially affect physical chemical However, mapping spatial distribution reactivity liquid remains challenge. Here, we demonstrate large area reactive sulfur-deficient aqueous solutions by coupling single-molecule localization microscopy fluorescence labeling using thiol chemistry. Our method, reminiscent PAINT strategies, relies on specific binding fluorescent probes hosting group to sulfur vacancies, allowing an uncertainty down 15 nm. Tuning distance between fluorophore docking site allows us control Foster resonance energy transfer (FRET) process reveal grain boundaries line due local irregular lattice structure. We further characterize kinetics over range pH conditions, evidencing reversible adsorption subsequent transitioning irreversible basic conditions. methodology provides simple fast alternative for large-scale nonradiative 2D be used situ spatially resolved monitoring interaction agents that has general implications defect engineering condition.