Development of a Hybrid NIR-II Thermometer Suitable for Drug Release

Accurate temperature measurements are important for cancer diagnosis, as localized temperature variations are often indicative of pathological conditions such as cancer and inflammation. The Nd³⁺-Yb³⁺ system is particularly promising due to its efficient energy transfer under 808 nm excitation, leading to distinct emissions from both ions in the second biological window (NIR-II, 1000-1700 nm). This spectral region is ideal for deep tissue imaging and temperature sensing, as it offers reduced scattering and absorption by biological tissues, enabling higher penetration depths and improved signal-to-noise ratios. This study presents a new hybrid thermometer composed of a silica core and a periodic mesoporous organosilica (PMO) shell decorated with LiLuF₄:Nd³⁺, Yb³⁺ nanoparticles, enabling temperature sensing and imaging in the NIR-II range. Additionally, these hybrid thermometers demonstrate drug release potential upon loading with doxorubicin as a model drug, indicating potential theranostic applications.