OICC Press International Journal of Biophotonics and Biomedical Engineering (IJBBE) 2980-9037 3 1 2023 09 22 Effect of Protein Corona Formation on Photonic Response of Upconverting Nanoparticles 49 56 10.30495/ijbbe.2023.1985468.1025 EN Nahid Ghazyani Faculty of Physics, Kharazmi University, Tehran, Iran Mohammad Hossien Majles Ara 1. Department of physics, Kharazmi University, Tehran, Iran 2. Applied Sciences Research Center, Kharazmi University, Karaj, Iran Journal Article 2023 09 22 NaYF4:Yb,Er is one of the efficient and well-known upconverting materials which emit photoluminescence light at 545 nm and 660 nm under an excitation of 980 nm. In this study, up-conversion nanoparticles using thermal decomposition method have been synthesized and characterized and phase transition from organic to aquas by synthesis a SiO2 shell have done successfully. The results show that the nonlinearity response of NaYF4: Yb, Er@SiO2 is same as NaYF4: Yb, Er and SiO2 has no effect on emission peaks it means that these nanoparticles are suitable for biomedical applications. Since it is necessary to know the photoluminescent behavior of UCNPs@SiO2 particles, thereby the fluorescence properties of up-conversion nanoparticles with SiO2 shell have been investigated in PBS, normal and cancerous human blood plasma. The results indicate that UCNP@SiO2 can be applicable in biological medias for therapy and diagnostic.