Preparation of Curcumin Derivative-Doped Silica Nano-photosensitizers and Its Photodynamic Inactivation Performance

In order to improve the photodynamic inactivation (PDI) effect of curcumin, three kinds of nano-photosensitizers SiO₂@X-Cur were prepared by covalently coupling halogenated curcumin derivatives X-Cur (X=F, Cl or Br) into silica by Stöber method. The successful preparation of SiO₂@X-Cur was confirmed by spectral characterization, doping amount determination and microstructure analysis. The results showed that SiO₂@F-Cur had the best comprehensive performance, and its saturated solubility in water was 308.33 μg/mL, which was 3.75-fold higher than that of curcumin. The singlet oxygen generation capability was particularly outstanding, achieving an indicator decay rate of 63% within 60 s. The light stability was considerably higher better than other samples (the fluorescence retention rate was 42.86% after irradiation for 30 min), and it also had high covalent doping stability. In addition, SiO₂@F-Cur had the best PDI effect on Vibrio parahaemolyticus. Under the condition of 2.0 mg/mL concentration and blue LED irradiation for 20 min, the total number of colonies decreased to 0.09 lg (CFU/mL). Therefore, SiO₂@F-Cur prepared in this study is an efficient and novel PDI nano-photosensitizer, which provide new ideas and research basis for guiding the development of novel aquatic product preservatives.