A Strategic Approach to Design Multi‐Functional RGB Luminescent Security Pigment Based Golden Ink with Myriad Security Features to Curb Counterfeiting of Passport

Abstract Authentication and verification of the most important government issued identity proof, i.e. passport has become more complex and challenging in the last few decades due to various innovations in ways of counterfeiting by fraudsters. Here, the aim is to provide more secured ink without altering its golden appearance in visible light. In this panorama, a novel advanced multi‐functional luminescent security pigment (MLSP) based golden ink (MLSI) is developed that provides an optical authentication and information encryption features to protect the legitimacy of the passport. The advanced MLSP is derived from the ratiometric combination of different luminescent materials to form a single pigment which emits red (620 nm), green (523 nm) and blue (474 nm), when irradiated via 254, 365 and 980 nm NIR wavelengths, respectively. It also includes magnetic nanoparticles to generate magnetic character recognition feature. The MLSI has been fabricated to examine its printing feasibility and stability over different substrates using the conventional screen‐printing technique against harsh chemicals and under different atmospheric conditions. Hence, these advantageous multi‐level security features with golden appearance in visible light is a new breakthrough toward curbing the counterfeiting of passport as well as bank cheques, government documents, pharmaceuticals, military equipment, and many more.