稀土掺杂硅酸钠镁锂无配体荧光水凝胶用于稀土离子检测OA

A novel ligand-free hydrogel based on rare-earth-doped Laponite(LP),designated as LP-Tb-Eu(LP doped with Tb3+and Eu3+),exhibits promising application potential in the detec-tion of Sm3+and Ho3+.Spectral analysis reveals that the strongest emission peak of Tb3+in LP-Tb is located at 544 nm,corresponding to the 5 D4→7 F5 transition,while that of Eu3+in LP-Eu is located at 615 nm,corresponding to the 5 D0→7 F2 transition.Further analysis of LP-Tb-Eu confirms the en-ergy transfer from Tb3+to Eu3+.After introducing Sm3+(LP-Tb-Eu@Sm3+)or Ho3+(LP-Tb-Eu@Ho3+)into the LP-Tb-Eu hydrogel,the fluorescence lifetime of Tb3+is altered,confirming the energy transfer from Tb3+to Sm3+and Tb3+to Ho3+.The intensity ratio of Tb3+to Eu3+(I544/I615)shows a good linear relationship with the concentrations of Sm3+and Ho3+,enabling quantitative detection of both ions.The detection limit for Sm3+concentration is as low as 0.82 μmol·L-1,while that for Ho3+is as low as 2.94 μmol·L-1.Additionally,trace additions of Sm3+or Ho3+induce significant changes in the emission intensity and color of LP-Tb-Eu,accompanied by a strong anti-interference capability.Therefore,LP-Tb-Eu serves as an efficient,visual fluorescent sensing material for Sm3+and Ho3+detection.