Optical authentication strategy using sodium alginate nanoparticles encapsulating lanthanide-doped aluminate

Abstract

Fluorescence has been reported as an interesting encoding approach to boost the efficacy of anticounterfeiting measures for commercial goods. Herein, we detail the preparation of an encoding ink made from alkaline earth-doped aluminate (AEA) encapsulated into sodium alginate (SA) nanoparticles (NPs), which can be employed for cutting-edge encoding purposes. Nanoparticles of SA were produced and encapsulated with AEA. AEA@SA nanoparticle-based authentication inks provide an excellent level of photostability and durability. Therefore, the fluorescence emission of the nanocomposite ink containing AEA@SA NPs was both robust and reversible. By altering the AEA@SA nanoparticle concentration, a range of composite inks with varied emission properties were presented. Both CIE (Commission Internationale de l'Eclairage) Lab and photoluminescence experiments proved that sheets printed with a uniform coating of nanocomposite inks are transparent under daylight but become green under UV irradiation. According to a morphological research performed using transmission electron microscopy (TEM), AEA particles have sizes between 12 and 18 nm, whereas AEA@SA NPs have diameters between 200 and 350 nm. The morphological analysis of prints was analyzed using a variety of microscopic and spectroscopic techniques. The ink rheology and mechanical characteristics of prints were examined. Green (517 nm) and colorless (365 nm) wavelengths were observed for emission and excitation, respectively. For the manufacturing of anticounterfeiting commercial items, the current optical authentication strategy can be described as a very efficient technique for authentication purposes.