Optimal fluorescence and photosensitivity properties of dual-functional NaYb1−xF4:Tmx3+ nanoparticles for applications in imaging guided photodynamic therapy

Abstract

The fluorescence and photosensitivity properties of NaYb_1−xF₄:Tm_x³⁺ nanoparticles were optimized to develop noninvasive near-infrared fluorescence imaging-guided photodynamic therapy. The emission at 800 nm from Tm³⁺ presented an exponential increase with an increase in the Tm³⁺ doping concentration from 0 to 2%. The photosensitivity properties of NaYb_1−xF₄:Tm_x³⁺ nanoparticles were also studied via the chemoprobe method, which used a reactive oxygen quencher, 1,3-diphenylisobenzofuran (DPBF). With the increase in the doping concentration of Tm³⁺, the generation rate of reactive oxygen species in NaYb_1−xF₄:Tm_x³⁺ nanoparticles decreased linearly at a rate of 0.3. The doping concentration of Tm³⁺ had two opposite effects on the 800 nm emission and generation rates of reactive oxygen species. The competitive relationship was discussed and an optimal value for the Tm³⁺ doping concentration of approximately 1% was determined. At this concentration, the energy of the Yb³⁺ excited state can be fully utilized, and the fluorescence and photosensitivity properties are an effective combination.