Single-molecule localization has been a helpful tool to identify the position of a single-molecule emitter. Capturing a single fluorophore with the camera pinpoints the molecule with great precision (∼1 nm), which is the main concept of single-molecule localization. Hence, we devised an optical system to demonstrate the light diffraction of materials with 2D as well as helical structures. Our optical configuration determined the positions of diffracted spots with a precision of several hundred nanometers (∼200–300 nm). This demonstration is very useful to elucidate the concept of light diffraction and single-molecule localization to undergraduate-level and high school students in physical chemistry or physics laboratories.

Nitrogen-containing polycyclic aromatic hydrocarbon (PAH) is the single basic moiety in N-doped graphene, the only metal-free catalyst reported to date to successfully produce the oxygen reduction reaction.