Nguyen, N.N. 2022. ENGINEERING THE NaYF4:Yb3+/Tm3+ UPCONVERSION NANOPARTICLE LUMINESCENCE ENERGY TRANSFER FOR A RATIOMETRIC pH INDICATOR. Dalat University Journal of Science. 13, 1 (Nov. 2022), 71–82. DOI:https://doi.org/10.37569/DalatUniversity.13.1.1044(2023).