Invisible luminescent inks and luminescent films based on lanthanides for anti-counterfeiting

The development of aqueous luminescent anti-counterfeiting materials and high-level anti-counterfeiting strategies are still great challenge. Herein, the luminescent inks emitting green, red, and yellow luminescence were prepared by the coordination between hyaluronic acid (HA) and lanthanides (Tb3+ and/or Eu3+) in water, and the corresponding luminescent films were further prepared by solution casting method. FT-IR and UV–Vis analysis demonstrated the formation of coordination bonds between hyaluronic acid (HA) and lanthanides. Luminescent spectra, luminescent decay curves and digital photographs suggested that the HA-lanthanides composite materials can be used as luminescent inks for anti-counterfeiting, and the corresponding luminescent films can be used as luminescent labels for anti-counterfeiting. More importantly, the multiple information encryption strategies were designed and used for high-level anti-counterfeiting. This work would open a new direction to further expand the functional applications of lanthanides-based luminescent materials.