Fig. 2

Latent fingermark images based on P-CD’s nanoparticles on different surfaces of (A) LCD screen of a smartphone, (B) metallic symbol of Visa credit card, (C) 20 Euro banknote and (D) magnetic band of credit card, (E) excitation-emission landscape for the raw spectra of P-CDs and corresponding contour plot shown in inset and excitation spectrum of P-CDs for the emission at 480-nm (black) and matching emission spectrum (red) along with the estimated emission profiles for P-CDs at 416/446/495 nm (orange, green, and blue) (Algarra et al. 2019) (Talanta, 2019, with permission from Elsevier)