Fig. 5From: Recent progress in the development of upconversion nanomaterials in bioimaging and disease treatment(Copyright 2015, 2012 and 2015. American Chemical Society. Reproduced with permission.)a Schematic illustration of the hydrothermal preparation synthetic procedure of UCNPs@TiO2 NCs [79]. b TEM images of the original NaYF4:Yb3+,Tm3+ cores (scale bar = 50 nm). c Sol–gel method for synthesized 2-aminoethyl dihydrogen phosphate-stabilized NaYF4:Yb3+,Er3+ nanoparticles (scale bar: 100 nm) [97]. d UPP@ovalbumin were prepared by microemulsion synthesis [98]. Back to article page