Developing multi-mode phosphor with non-visible ranges for advanced anti-counterfeiting in medicine

Medicine counterfeiting is a serious issue worldwide, involving potentially devastating health repercussions. Optical technologies have emerged as a promising solution for anti-counterfeiting tagging of pharmaceuticals. However, conventional systems relying on human-visible authentication modes remain susceptible to trial-and-error decryption, posing security vulnerabilities. To address this limitation, we have developed a novel multi-mode phosphor, Mg 3 Y 2 Ge 3 O 12 :Bi 3+ /Pr 3+ /Yb 3+ /Er 3+ (MYGBP-Yb/Er), featuring distinctive visible and non-visible spectral characteristics for high-security medicine anti-counterfeiting. This material simultaneously demonstrates green up-conversion luminescence (UCL) under 980 nm excitation, red down-shifting luminescence (DSL) upon UV stimulation, and persistent luminescence (PersL) spanning UV to visible spectral regions after UV excitation. The UV PersL component, while completely invisible to human vision, serves as a robust hidden authentication layer that can only be revealed through specialized detection using bandpass filters coupled with charge-coupled device (CCD) cameras. This unique combination of visible and non-visible luminescent features enables the realization of information protection that resists conventional counterfeiting attempts. In addition, changing the doping elements (such as Tb 3+ or Ho 3+ ) can achieve the regulation of the luminescence performance. Ultimately, we establish a sophisticated multi-level medicine verification system based on these phosphors, enhancing protection against forgery through its integrated visible authentication and CCD-readable covert security features.