Construction of a nanofluorescent probe GdPO4·H2O:20%Tb3+@GdPO4@PEG and study of its properties

• Published in: Ceramics international Vol. 50; no. 20; pp. 38841 - 38850
• Main Authors: Wang, Qianqian, Wu, Jinxiu, Wu, Baolong, Jia, Huiling, Zhang, Yiming, Liu, Zhaogang, Hu, Yanhong, Zhang, Xiaowei, Li, Jianfei, Wang, Shengquan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.10.2024
• Subjects: Double core-shell structure; Fluorescence property; GdPO4; H2O:20%Tb3; Magnetic property; Nano-fluorescent probe; Magnetic property; Nano-fluorescent probe; Fluorescence property; Double core-shell structure; H2O:20%Tb3; GdPO4
• ISSN: 0272-8842
• DOI: 10.1016/j.ceramint.2024.07.400

This study aimed to enhance the surface defects and fluorescence properties of GdPO₄·H₂O:Tb³⁺ nanophosphors and develop a nanoscale dual-layer core-shell structured fluorescent probe, GdPO₄·H₂O:20%Tb³⁺@GdPO₄@PEG. Hydrothermal and microwave synthesis methods were employed. The former controlled the ratio of GdPO₄·H₂O:Tb³⁺ to GdPO₄, forming core-shell structured nanophosphors GdPO₄·H₂O:20%Tb³⁺@GdPO₄ with varying shell thicknesses. The latter involved Polyethylene Glycol (PEG) as a surface modification agent, resulting in a high-performance dual-layer fluorescent nanomaterial, GdPO₄·H₂O:20%Tb³⁺@GdPO₄@PEG. We characterized the modified and unmodified fluorescent powders for their structural, morphological, optical, and magnetic properties using XRD, SEM, TEM, FTIR, TG, FL, and VSM techniques. Both pre- and post-coated nanophosphors exhibited a singular hexagonal crystal structure with an ellipsoidal morphology, average particle sizes of approximately 40–50 nm, and coating layer thicknesses of about 5–15 nm. The excitation and emission peak positions remained relatively constant before and after the coating process. The dual-layer core-shell nano-fluorescent probe demonstrated significantly enhanced fluorescence intensity due to reduced non-radiative transition rates. Moreover, both pre- and post-coated nanophosphors exhibited excellent paramagnetic properties. This research successfully improved the hydrophilicity and biocompatibility of GdPO₄·H₂O:Tb³⁺ nanophosphors while concurrently enhancing their luminescent and magnetic performance.