Coumarin derivative dye sensitized NaYGdF4:Yb,Er nanoparticles with enhanced NIR II luminescence for bio-vascular imaging

Unveiling the Excited-State Dynamics and Interfacial Interactions in Dye-Sensitized NaNdF4 Nanoparticles for Efficient Photothermal Effect

Near-infrared (NIR) dyes can overcome the weak absorption of lanthanide nanoparticles (NPs) by antenna sensitization, offering new avenues to develop efficient and versatile lanthanide nanomaterials. However, current research on dye-sensitized lanthanide NPs for photothermal conversion is still preliminary, and the involved excited-state dynamics and interfacial interactions remain elusive. Herein, steady-state/transient absorption spectroscopy and theoretical calculation are used to investigate the coordination and aggregation states of cypate dyes on NaNdF4 NPs, revealing the influence of interfacial interactions on resonant energy transfer. Synergetic heat-generation mechanism of lanthanide cross-relaxation and dye intermolecular collisions is further proposed. The photothermal conversion efficiency of cypate-NaNdF4 nanocomposites reaches 50.4%, outperforming those of typical photothermal materials with high NIR absorption. Moreover, the intersystem crossing of cypate can be inhibited due to the depopulation of the S1 exciton via ET, thereby improving anti-photobleaching ability. These dye-sensitized NaNdF4 nanocomposites exhibit superior photothermal effect, stability and NIR-II luminescence, showing great potential in theranostic applications.

Advances in Lanthanide-Based NIR-IIb Probes for In Vivo Biomedical Imaging

The past decades have witnessed the significant development and practical interest of in vivo biomedical imaging technologies and optical materials in the second-near infrared (NIR-II, 1000-1700 nm) window. Imaging with the extended emission wavelength toward the long-wavelength end (NIR-IIb, 1500-1700 nm) further offers micrometer imaging resolution and centimeter tissue penetration depth by taking advantage of the much-reduced photon scattering and near-zero tissue autofluorescence background, which have become a very hot research area. This review focuses on the recent advances in the development of lanthanide-based NIR-IIb probes for in vivo biomedical applications. The progress including ratiometric imaging, multiplexed imaging for wide-field and microscopy, lifetime multiplexing and sensing, persistent luminescence, and multimodal imaging is summarized. Challenges and future directions concerning the investigation of the photophysical and photochemical properties of NIR-IIb probes, the selection of near-infrared cameras as well as the potential extension of the NIR-IIb imaging sub-window are pointed out. This review will inspire readers who have a strong interest in developing optical imaging technology and long-wavelength fluorescence probes for high-contrast in vivo biomedical applications.

Upconversion and NIR-II luminescent rare earth nanoparticles combined with machine learning for cancer theranostics

How to develop contrast agents for cancer theranostics is a meaningful and challenging endeavor, and rare earth nanoparticles (RENPs) may provide a possible solution. In this study, we initially modified RENPs through the application of photodynamic agents (ZnPc) and targeted the bevacizumab antibody for cancer theranostics, which was aimed at improving the therapeutic targeting and efficacy. Subsequently, we amalgamated anthocyanin with the modified RENPs, creating a potential cancer diagnosis platform. When the spectral data were obtained from the composite of cells, the crucial information was extracted through a competitive adaptive reweighted sampling feature algorithm. Then, we employed a machine learning classification model and classified both the individual spectral data and fused spectral data to accurately predict distinctions between breast cancer and normal tissue. The results indicate that the amalgamation of fusion techniques with machine learning algorithms provides highly precise predictions for molecular-level breast cancer detection. Finally, in vitro and in vivo experiments were carried out to validate the near-infrared luminescence and therapeutic effectiveness of the modified nanomedicine. This research not only underscores the targeted effects of nanomedicine but also demonstrates the potent synergy between optical spectral technology and machine learning. This innovative approach offers a comprehensive strategy for the integrated treatment of breast cancer.