Luminophoric organic molecules for anticounterfeit printing ink applications: an up-to-date review

Counterfeiting of currency, valuable documents, and branded products remains an extremely challenging concern for governments, companies, and consumers worldwide, which poses grave monetary, safety, and health consequences. In recent years, organic luminescent materials are being widely used in various fields, especially in advanced optical displays and solid-state lighting as they exhibit exceptional optical properties and chemical stability. These features facilitated the use of organic luminophores as highly promising materials in anticounterfeiting applications too. This review introduces the concerns due to counterfeiting, introduces various techniques to combat the growing threat, and further acknowledges the different types of luminophores currently used in antiforging applications. The article mainly highlights the recent developments in organic solvent-based and eco-friendly water-based formulations for anticounterfeiting purposes that contain organic molecules with various unique features as fluorescent pigments. Furthermore, the limitations of the currently used organic materials and future prospects for fabricating smart luminogens to tackle the counterfeiting problems are also discussed. This review would benefit researchers who are currently working and those who have just entered this fascinating and evolving, but highly demanding, area of security printing.