Structure-Activity Optimization of Luminescent Tb-doped LaF₃ Nanoparticles

Area of Science:

• Materials Science
• Nanotechnology
• Spectroscopy

Background:

• Lanthanum fluoride nanoparticles (LaF₃ NPs) are promising for bioanalytical applications.
• Terbium (Tb) doping can enhance luminescence properties.
• Controlling doping concentration and surface chemistry is crucial for optimizing performance.

Purpose of the Study:

• To synthesize and characterize Tb-doped LaF₃ NPs with varying Tb concentrations.
• To investigate the effect of Tb doping on crystal structure, size, and spectroscopic properties.
• To evaluate the impact of dipicolinic acid surface capping on luminescence.

Main Methods:

• Inductively coupled plasma atomic emission spectroscopy (ICP-AES) for elemental composition.
• Transmission electron microscopy (TEM) and X-ray diffractometry (XRD) for solid-state characterization.
• Dynamic light scattering (DLS), Taylor dispersion analysis, and laser Doppler electrophoresis for solution-state analysis.
• Spectroscopic studies of bare and surface-capped NPs.

Main Results:

• Hexagonal crystal structure observed up to 70% Tb doping; phase admixture at 80-90% Tb; orthorhombic phase for pure TbF₃.
• Dipicolinic acid capping enhanced luminescence lifetime and brightness by protecting Tb³⁺ from water quenching.
• A 40% Tb doping concentration demonstrated optimal performance.

Conclusions:

• Tb-doped LaF₃ NPs can be tailored for enhanced luminescence.
• Surface functionalization with dipicolinic acid significantly improves luminescent properties.
• 40% Tb-doped LaF₃ NPs are identified as ideal for bioanalytical applications.