Nanocomposites of nitrogen-doped carbon dots/hydrotalcite with enhanced solid-state fluorescence for the recognition of latent fingerprints.

In this work, a green emissive nanocomposite was synthesized by embedding nitrogen-doped carbon dots into hydrotalcite (N-CD/hydrotalcite) a hydrothermal process for the recognition of latent fingerprints (LFPs). Good dispersion of the nano-sized N-CD on the surface of hydrotalcite overcomes the fluorescence quenching of N-CD in the solid state and can enhance solid-state fluorescence. N-CD/hydrotalcite emits stable strong green fluorescence even at different excitation wavelengths and exhibits good selectivity and sensitivity for the visualization of LFPs on various substrates such as glass slides, tiles, leather, aluminum foil, printing paper, colored surfaces of plastic packing, copper foil, planks, leaves, currencies, and bar codes.