808 nm laser triggered self-monitored photo-thermal therapeutic nano-system Y2O3: Nd3+/Yb3+/Er3+@SiO2@Cu2S

A multifunctional photo-thermal therapeutic nano-platform Y 2 O 3 : Nd 3 + / Yb 3 + / Er 3 + @ SiO 2 @ Cu 2 S (YR-Si- Cu 2 S ) was designed through a core–shell structure, expressing the function of bio-tissue imaging, real-time temperature detection, and photo-thermal therapy under 808 nm light excitation. In this system, the core Y 2 O 3 : Nd 3 + / Yb 3 + / Er 3 + (YR) takes the responsibility of emitting optical information and monitoring temperature, while the shell Cu 2 S nano-particles carry most of the photo-thermal conversion function. The temperature sensing characteristic was achieved by the fluorescence intensity ratio using the thermally coupled energy levels (TCLs) S 3 / 2 4 / H 2 11 / 2 of Er 3 + , and its higher accuracy for real-time temperature measurement in the bio-tissue than that of an infrared thermal camera was also proved by sub-tissue experiments. Furthermore, the photo-thermal effect of the present nano-system Y 2 O 3 : Nd 3 + / Yb 3 + / Er 3 + @ SiO 2 @ Cu 2 S was confirmed by Escherichia coli ( E. coli ) and Staphylococcus aureus ( S. aureus ) ablation. Results indicate that YR-Si- Cu 2 S has application prospect in temperature-controlled photo-thermal treatment and imaging in bio-tissues.