Construction of Multifunctional Core-Shell Structure Nanoprobe Integrating Nir Dual-Mode Optical Thermometer and Nuclear Magnetic Imaging

Precise temperature regulation and imaging are critical for in vivo photothermal treatment. The goal of this work is to realize non-contact temperature measurement and imaging in biological tissues by building a multifunctional nano-platform using optical temperature probes and imaging for biological diagnosis and therapy. Here, NIR dual-mode temperature probes of NaYF4: Nd/Yb/Gd@NaNdF4 were designed according to the LIR-I of 4F3/2 → 4I9/2/2F5/2 → 2F7/2 levels in 850 – 1025 nm and LIR-II of 2F5/2 → 2F7/2/4F3/2 → 4I11/2 in 950 – 1100 nm from the emissions of Nd3+/Yb3+. Transmission electron microscope (TEM) and X-ray diffraction (XRD) data of the sample demonstrate its superior dispersibility and accurate structure. The integrated intensity ratio centered around various luminescence intensity peaks is used as a temperature sensor since luminescence intensity is temperature-dependent. Additionally, the temperature sensing capabilities of two ratio temperature sensors were examined under 808 nm laser excitation, utilizing LIR (luminescence intensity ratio) technology. Furthermore, the MRI test indicated that the sample exhibited good imaging capacity when Gd3+ was added. These results assure the auspicious application prospects of the samples in temperature sensing, photothermal therapy, and biomedical imaging.