Fig. 1: Structure characterizations of the helical fibers.

Low-magnification (a) and high-magnification (b) SEM images of the helical fibers. TEM image (c) and high-resolution TEM image (d) and STEM and elemental mapping images (e) of the helical fibers. f AFM image coupled with height-profile of the helical fibers. g FT-IR spectra of NGQDs and helical fibers. h Time-dependent PL spectra during the self-assembly of NGQDs, inset shows the optical photographs taken under UV (365 nm) and in dark.