High-resolution imaging of electric field enhancement and energy-transfer quenching by a single silver nanowire using QD-modified AFM tips

Plasmonic nanostructures can profoundly affect the optical properties of light absorbers and emitters. Using quantum dot-modified-atomic force microscopy (AFM) tips as a nanoscale light source, the topological features of a Ag nanowire and its effect on the fluorescence intensity and lifetime of the QDs can be simultaneously imaged with AFM spatial resolution. Modeling of the QD-nanowire interaction and the contrasts in the fluorescence intensity and lifetime images suggests that this novel method can be used for direct high-resolution mapping of the electric field distributions and energy-transfer quenching near metallic nanostructures.