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

A multifunctional photo-thermal therapeutic nano-platform Y2O3: Nd3+/Yb3+/Er3+@SiO2@Cu2S 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 Y2O3: Nd3+/Yb3+ /Er3+ (YR) takes the responsibility of emitting optical information and monitoring temperature, while the shell Cu2S 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-4(3)/2/ H-2(11)/2 of Er3+, and its higher accuracy fur 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 Y2O3: Nd3+/Yb3+/Er3+@SiO2@Cu2S was confirmed by Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) ablation. Results indicate that YR-Si-Cu2S has application prospect in temperature-controlled photo-thermal treatment and imaging in bio-tissues. (C) 2019 Chinese Laser Press