Synthesis of an efficient paramagnetic ZnFe2O4 agent for NIR-I/II responsive photothermal performance

Photothermal therapy (PTT) is a promising alternative strategy to traditional cancer therapy. Photothermal agents (PTAs) in the second near-infrared (NIR) window (1000-1350 nm) hold excellent potential for enhanced PTT treatment of deep tumors compared with the first NIR window (780-1000 nm). Herein, paramagnetic ZnFe2O4 nanospheres with an average of 150 nm and defective structure were synthesized by a simple solvothermal method. The samples were characterized by X-ray diffraction, scanning electron microscopy, UV-vis-NIR spectroscopy, photoluminescence spectrum, and vibrating sample magnetometer. The photothermal mechanism and performance under bio-safe NIR-I/II laser irradiation have been discussed in detail. The samples represented good magnetic property and photothermal conversion efficiency (PCE) of 64.64% (808 nm, 0.33 W cm(-2)) and 35.75% (1064 nm, 1 W cm(-2)), surpassing many previous nano-PTAs active in the NIR-./II region. This work provides a simple method to acquire clinical paramagnetic PTAs in bio-imaging mediated NIR-II photothermal therapy. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

Photothermal therapy (PTT) is a promising alternative to traditional cancer therapy, and using photothermal agents (PTAs) in the second near-infrared window shows great potential for enhanced PTT treatment of deep tumors. In this study, paramagnetic ZnFe2O4 nanospheres with a defective structure were synthesized, and their characteristics and photothermal performance were discussed under NIR-I/II laser irradiation. The samples exhibited good magnetic properties and high photothermal conversion efficiency, surpassing previous nano-PTAs in the NIR-I/II region. This work provides a simple method to obtain clinical paramagnetic PTAs for NIR-II photothermal therapy.