Spiropyran-Modified Upconversion Nanoparticles for Tunable Fluorescent Printing
Hanbing Zhang, Zihao Chen, Yan-Rong He, Shuangye Yang, Jie Wei
Abstract
Manipulating fluorescence color may enable multifunctionality access to many applications and remains a huge challenge. In this paper, an efficient approach for achieving obvious fluorescence with tunable color via spiropyran-modified upconversion nanoparticles is reported. In this way, the nanoparticles can generate yellow emission color by the superposition of fluorescence under UV and near-infrared light. The nanoparticles are configured into inks that can be printed or sprayed into diverse coded patterns which emitted various fluorescence under different lights. These patterns reveal the great potential of spiropyran-modified upconversion nanoparticles in multilevel anticounterfeiting and pattern display.