Professor Tan Jing's research team published the paper “Surface ionization-induced tunable dynamic phosphorescence colors from carbon dots on paper for dynamic multimode encryption” in the famous journal Carbon (Q1, IF=11.307, DOI of paper: 10.1016/j.carbon.2022.03.063). Qijun Li is the first author of the paper, Songnan Qu and Jing Tan is the corresponding author.

In the paper, we developed a new strategy using phenolic hydroxyl ionization to induce CDs surface state phosphorescence to achieve external stimulus-tunable dynamic phosphorescence color outputs. The results show that phenolic hydroxyl ionization has great utility in enhancing ISC rates, passivating surface defects and reducing non-radiative decay, thereby inducing surface state-relative blue phosphorescence. Combined with the carbon core state-related yellow-green phosphorescence, the phosphorescence colors of CDs could be tuned by time evolution, excitation, alkali, and heat, realizing multimode dynamic color tuning from yellow-green to blue. Finally, owing to their unique multimode dynamic phosphorescence color properties, multimode encryption and smart 3D codes with anti-counterfeiting and monitoring functions for medicine during transport or storage have been developed, and a computer decryption program is designed to realize the identification of authenticity of drugs and real-time monitoring of transportation process.

The work was supported by the National Nature Science Foundation of China, the Natural Science Foundation of Jiangsu, the Primary Research & Development Plan of Zhenjiang-Modern Agriculture, the Science and Technology Development Fund of Macau SAR, and Fund from the University of Macau.

Paper link: https://doi.org/10.1016/j.carbon.2022.03.063。

Schematic diagram of preparation process and phosphorescent emission characteristics

Intelligent three-dimensional code with drug transportation, storage, anti-counterfeiting and monitoring functions