A novel multi-functional FeZnCuInS/ZnS-TPPS4 conjugates as a promising theragnostic tool for combined photodynamic and photothermal therapy applications

Researchers are focusing on developing combined therapy strategies for tumor treatment due to their improved therapeutic outcomes. In this present work, we synthesized FeZnCuInS/ZnS– meso–tetra–(4–sulfonatophenyl) porphyrin (FeZCIS/ZnS–TPPS 4 ) conjugate as a promising multifunctional nanoprobe for dual or combined photodynamic and photothermal therapy applications. Firstly, the Fe–doped quaternary quantum dots (QDs) were synthesized using a reflux method employing eco–friendly materials. While anionic TPPS 4 was synthesized by acidifying a meso–tetraphenylporphyrin precursor with sulphuric acid. Thereafter, the porphyrins and QDs were conjugated together via sulphonamide bond between four sulfonyl groups of TPPS 4 and amine groups from GSH capped QDs. A comparative analysis between the QDs, TPPS 4 and the conjugated, revealed that the conjugated porphyrins to QDs exhibited improved characteristics, including increased singlet oxygen quantum yield (SOQY) and enhanced heat generation. Furthermore, the dark toxicity of all the as–synthesized materials was evaluated against four different cancer cell lines, namely, breast (FM3A–Luc), prostate (MBT2–Luc), osteosarcoma (LM8–Luc), and histiocytoma (KM–Luc). The results showed excellent cell survival for all the synthesized materials. The biocompatibility, 1 O 2 generation, and heat production of the as–synthesized conjugate shows its potential for combined photodynamic therapy (PDT) and photothermal therapy (PTT) applications.