Regulating the Size of Antimony Nanoparticles to Enhance the Photoresponse in the Near-infrared Region and Anti-hepatoma Cell Activity

Lingling Huang¹Yimin Gong^2,3,4Zhijian Chen^5,6Yanjun Tan^2,3Qian Gao^2,3Yilei Wang^2,3Yuyu Gao^2,3Wanting Cheng^2,3Weiyuan Liang^2,3*Xiaoli Yang^1,2,3

• ¹College of Pharmacy, Guangxi Medical University, Nanning, China
• ²Scientific Research Center, Guilin Medical University, Guilin, China
• ³Guangxi Health Commission Key Laboratory of Disease Proteomics Research, Guilin, China
• ⁴Department of chemistry, Fudan University, Shanghai, China
• ⁵Key Laboratory of Clinical Laboratory Medicine of Guangxi Department of Education, Nanning, China
• ⁶Department of Clinical Laboratory, The First Affiliated Hospital of Guangxi Medical University, Nanning, China

Antimony (Sb) is a typical Group VA semimetal, which has rarely been experimentally and theoretically investigated in plasmonic photothermal or photodynamic therapies, possibly due to the lack of effective morphology control methods for preparing high-quality Sb nanocrystals. In this study, an effective ligand-guided growth strategy was employed to synthesize Sb nanoparticles (Sb NPs) with high photothermal conversion efficiency (PTCE) and biocompatibility in a controllable manner. Experimentally, the modulation effect of different sizes on the localized surface plasmon resonance (LSPR) of Sb NPs was successfully observed. As the size of Sb NPs increased from 40 nm to 70 nm, the UV-vis absorption peak was observed to red-shift from 520 nm to 810 nm. When the SPR resonance frequency matched the external excitation light (808 nm), the PTCE of Sb NPs reached up to 59.3%, which was significantly higher than most reported photothermal agents. Sb NPs also exhibited sensitivity to 660 nm laser and generated reactive oxygen species (ROS), providing a basis for photodynamic therapy (PDT). Additionally, multifunctional nanodrugs based on Sb NPs were sequentially coated with polydopamine (PDA) and folic acid-modified polyethylene glycol (PEG) for high-efficiency photothermal/photodynamic therapy of in vitro hepatoma cells. This work can stimulate further theoretical and experimental studies on the LSPR of Sb NPs and other semi-metallic nanomaterials, and promote the various potential applications of semimetals in biomedicine.