Synthesis and Characterization of Zinc-Oxide-Based Nanoparticles for Anti-Counterfeiting Applications

This thesis project aimed to develop an anti-counterfeiting system for pharmaceutical packaging using zinc-oxide-based nanoparticles. I synthesized nanoparticles incorporating several different metals at different concentrations and under different synthesis conditions, yielding nanoparticles emitting at various visible-range frequencies. I then functionalized the nanoparticles with oleic acid to allow integration with an organic ink typically used by drug-packaging companies. I verified that the integration was successful and tested the resulting ink on the paperboard typically used in pharmaceutical packaging, conducting printing tests both in the laboratory and at a pharmaceutical packaging company using their offset printing technology. Finally, I analyzed the nanoparticles - both in solution and integrated into the ink and printed on paperboard - using various spectroscopic and microscopic techniques, including dynamic light scattering, spectrophotometry, fluorimetry, FTIR spectroscopy, SEM and energy-dispersive X-ray spectroscopy. In conclusion, I was able to demonstrate a tailorable anti-counterfeiting ink additive that can be recognized at multiple levels, starting from fluorescent emission visible to the naked eye, to spectroscopic analysis of light emission, and even to specific compositional analysis verifiable only with the appropriate laboratory equipment. Its practical applicability to anti-counterfeiting strategies in the pharmaceutical industry will be discussed.