Fig. 1
From: Photosensitizing deep-seated cancer cells with photoprotein-conjugated upconversion nanoparticles
Schematic and construction of CS-UCNPs and Co-UCNPs as cancer cell-targeted PDT agents. a Schematic illustrations of cancer cell-targeted PDT using UCNP-KR-LP (top) and an efficient photon ET pathway from UCNPs to KR (bottom). b TEM images of core (NaYF4:Yb3+) and core-shell (NaYF4:Yb3+@NaYF4:Er3+) UCNPs. c EDS spectrum of CS-UCNPs (NaYF4:Yb3+@NaYF4:Er3+). The inset shows EDS line scan analysis of the TEM image of a single CS-UCNP. d−e PL intensity spectra of core (NaYF4:x% Yb3+, 2% Er3+) and core-shell (NaYF4:40% Yb3+@NaYF4:y%Er3+) UCNPs at an excitation wavelenth of 980 nm with varying Yb3+ concentrations in the core (d) and Er3+ doping concentrations in the outer layer (e). The inset shows the PL intensity at 550 nm as a function of the concentration (mol%) of either Yb3+ or Er3+. CS-UCNP, core-shell upconversion nanoparticle; Co-UCNP, co-doped upconversion nanoparticle; KR, KillerRed; LP, lead peptide; ROS, reactive oxygen species; PL, photoluminescence