Confined Synthesis of Carbon Dots with Red Room-Temperature Phosphorescence and Dual-Modal Imaging
Runkai Sun, Jiancheng Liu, Chao Li, Wendi Liu, Cheng Cui, Yanjun LinAbstract
Red afterglow-emitting nanomaterials are in great demand for bioimaging and advanced luminescent technologies and applications, but current candidates suffer from high fabrication costs, poor biocompatibility, and low luminescence efficiency. To address these challenges, amino acid was intercalated into layered double hydroxides (LDHs) as a carbon source, enabling the synthesis of a red-emitting room-temperature phosphorescence (RTP) material (Mn@CDs-LDH) with Mn2+. This material exhibits phosphorescence centered at 660 nm with a phosphorescence quantum yield (PQY) of 2.28%. Structural and energy-level analyses reveal that the phosphorescence arises from the energy transfer process between carbon dots (CDs) and Mn2+ octahedra. Notably, LDH not only prevents the oxidation of Mn2+ but also facilitates radiative transitions to enhance phosphorescence efficiency. With desirable optical properties and stability, Mn@CDs-LDH demonstrates application potential in multicolor displays and in vivo dual-mode imaging.