Abstract: Dual-emission gel spheres（lanthanides（Ln）@carbon dots（CDs）@alginate（Alg）,Ln = Eu, Tb） were successfully prepared using a simple injection method, with Alg as the matrix and Ln and CDs as emission centers. Furthermore, their structures and luminescent properties were characterized. The results revealed that the Ln@CDs@Alg gel spheres emitted red and green fluorescence under ultraviolet（UV） excitation at 254 nm, and blue fluorescence under UV excitation at 365 nm. Based on this property, an array was developed that displayed blue fluorescence under UV excitation at 365 nm for information protection and revealed the encoded information “MY” in red and green fluorescence under UV excitation at 254 nm. The unique features demonstrated by the gel sphere array presented significant potential for applications in the field of anti-counterfeiting.

Key words: lanthanide ions(Ln³⁺), carbon dots（CDs）, gel spheres, anti-counterfeiting