A novel visible light excited room temperature afterglow luminescent carbon dots/boric acid composite for information encryption and Fe3+ sensing

Visible light excited room temperature afterglow luminescent carbon dots are rare and most of them are excited by ultraviolet light, which has potential phototoxicity, and the quantum yield of afterglow is always low. This article reports a novel room temperature afterglow luminescent carbon dots/boric acid composite (BCDs composite) that can be excited by visible light such as 450 nm LED light, flashlight, and even mobile phone flashlight with high afterglow quantum yield of 48.4 % and long afterglow lifetime of 866 ms. Based on their excellent afterglow emission property, they can be applied for information security under humidity stimulation. Under daily storage condition, the information written by BCDs composite has no afterglow, and when dried with a hair dryer, the information was lighted by afterglow. Meanwhile, the BCDs composite can also be used for highly sensitivity Fe3+ sensing with a low detection limit of 102 nM in Tris-HCl buffer. This study not only successfully developed a novel room temperature long afterglow luminescent carbon dot based nanomaterial with multiple uses and visible light excitation, but also may provide ideas for the design of subsequent room temperature afterglow carbon dots and carbon dot based sensing probes.