Core-Shell Interface Engineering Strategies for Modulating Energy Transfer in Rare Earth-Doped Nanoparticles

Area of Science:

• Biomedical Engineering
• Materials Science
• Nanotechnology

Background:

• Rare earth-doped nanoparticles (RENPs) are advanced biomaterials with multilayered core-shell structures enabling diverse biomedical applications, including orthogonal excitation.
• Existing synthesis methods, layer-by-layer (LBL) and seed-assisted (SA), yield RENPs with differing spectral properties.

Purpose of the Study:

• To comparatively analyze the elemental distribution and spectral characteristics of RENPs synthesized via LBL and SA methods.
• To elucidate how synthesis strategies influence RENP spectral performance for biomedical applications.

Main Methods:

• Comparative analysis of elemental distribution using techniques like electron microscopy and spectroscopy.
• Characterization of spectral properties, including luminescence and excitation spectra.
• Evaluation of RENP performance in orthogonal biomedical probes for in vivo imaging and photodynamic therapy.

Main Results:

• The SA strategy produces RENPs with a distinct elemental interface, unlike the partial precursor mixing in the LBL strategy.
• This distinct interface in SA-synthesized RENPs minimizes energy loss between heterogeneous elements, optimizing spectral characteristics.
• SA-synthesized RENPs demonstrated a 4.3-fold enhancement in NIR-II in vivo imaging and a 2.1-fold increase in ROS-related photodynamic therapy efficacy.

Conclusions:

• Synthesis method critically modulates RENP spectral properties, with the SA strategy offering superior performance.
• The SA method's ability to create a refined inert interface is key to preventing energy loss.
• This research enables the rational design of orthogonal RENP biomedical probes with enhanced imaging and therapeutic capabilities.