Synthesis of Sn nanocluster@carbon dots for photodynamic therapy application

Recently, photodynamic therapy (PDT) has been extensively applied in clinical and coadjuvant treatment of various kinds of tumors. However, the photosensitizer (PS) of PDT still lack of high production of singlet oxygen (O-1(2)), low cytotoxicity and high biocompatibility. Herein, we propose a facile method for establishing a new core-shell structured Sn nanocluster@carbon dots (CDs) PS. Firstly, Sn4+@S-CDs complex is synthesized using the sulfur-doped CDs (S-CDs) and SnCl4 as raw materials, and subsequently the new PS (Sn nanocluster@CDs) is obtained after vaporization of Sn4+@S-CDs solution. Remarkably, the obtained Sn nanocluster@CDs show an enhanced fluorescence as well as a higher O-1(2) quantum yield (QY) than S-CDs. The high O-1(2) QY (58.3%) irradiated by the LED light (400-700 nm, 40 mW/cm(2)), induce the reduction of 4T1 cancer cells viability by 25%. More intriguingly, no visible damage happens to healthy cells, with little impact on liver tissue due to renal excretion, both in vitro and in vivo experiments demonstrate that Sn nanocluster@CDs may become a promising PS, owning a high potential for application in PDT. (C) 2021 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.

Automated summary

A new core-shell structured Sn nanocluster@carbon dots photosensitizer with high O-1(2) quantum yield and fluorescence intensity is proposed. Upon light irradiation, this photosensitizer can effectively reduce cancer cell viability, with minimal impact on healthy cells and liver tissue.