Anti-counterfeiting ink based on polymer nanoparticles containing spiropyran and Aza-BODIPY for artificial industries

Counterfeiting in various artificial industries has been a serious challenge for the authenticity of cultural products. Security marking of original crafts with high-security anti-counterfeiting inks could be a possible way to limit counterfeiting in art products. In this study, spiropyran-containing colloidal polymer particles were synthesized using emulsifier-free emulsion polymerization. Scanning electron microscopy and dynamic light scattering were used to analyze morphology and size of the nanoparticles. Anti-counterfeiting inks based on Förster resonance energy transfer (FRET) were then formulated via physical doping of aza-BODIPY into the colloidal polymer latex samples, where the cemically incorporated spiropyran into the particles acts as the donor and aza-BODIPY plays the role of the acceptor. Fluorescence and ultraviolet-visible spectroscopy were used to evaluate the FRET process possibility and efficiency. The high-security ink was subsequently used for security marking of a special handicraft. Silk fibers were impregnated with both of the photochromic and FRET-based inks in different concentrations and used in weaving the petal patterns. This aqueous FRET-based ink could also be used for security marking of different documents and also various art products. This study could help to reduce forgery in artificial industries, for authentication of the original handicrafts form the fakes, and prevent from counterfeiting in art industries.