Construction and research progress of fluorescent carbon dots in intelligent anti‐counterfeiting ink system

Abstract The rapid growth of global trade has led to a significant rise in counterfeit goods, posing a serious risk to the safety of product circulation. This situation necessitates the urgent development of advanced intelligent anti‐counterfeiting technologies that can respond at multiple levels. Carbon dots (CDs), which are fluorescent nanomaterials measuring less than 10 nm, possess adjustable luminescence properties, are environmentally friendly and have excellent biocompatibility, making them a promising alternative to traditional anti‐counterfeiting methods. This paper provides a comprehensive review of the recent progress in single, double and multicolour CDs used in anti‐counterfeiting inks over the last 4 years. It examines technological advancements from static marking to intelligent interactive security systems and emphasises the design strategies and various applications for creating dynamically responsive invisible inks and intelligent information encryption systems. The paper discusses the synergistic effects of various factors, including quantum confinement, surface defect‐state radiative transitions and enhanced emission through intramolecular and intermolecular cross‐linking. It also summarises the impact of dynamic regulation mechanisms, such as solvent polarity affecting Stokes shift, concentration‐dependent aggregation‐induced luminescence changes and pH‐responsive excited‐state proton transfer, on the multi‐dimensional representation of anti‐counterfeiting information. Finally, the paper identifies existing challenges and potential solutions while highlighting the significant promise of CDs in the realm of anti‐counterfeiting inks.