Mesoporous‐Silica‐Coated Up‐Conversion Fluorescent Nanoparticles for Photodynamic Therapy

Abstract Near‐infrared (NIR)‐to‐visible up‐conversion fluorescent nanoparticles have potential to be used for photodynamic therapy (PDT) in deep tissue because NIR light can penetrate thick tissue due to weak absorption in the optical window. Here a uniform layer of mesoporous silica is coated onto NaYF 4 up‐converting nanocrystals, with a large surface area of ≈770 m 2 g −1 and an average pore size of 2 nm. A photosensitizer, zinc phthalocyanine, is incorporated into the mesoporous silica. Upon excitation by a NIR laser, the nanocrystals convert NIR light to visible light, which further activates the photosensitizer to release reactive singlet oxygen to kill cancer cells. The photosensitizer encapsulated in…

• NU
  National University of Singapore
• BR
  Biomedical Research Council