Non-photobleaching YAG:Ce nanoparticles for optical imaging with blue excitation

Abstract

Hydrophilic Y₃Al₅O₁₂ (YAG) and (Y_xGd_1−x)₃Al₅O₁₂ nanoparticles (NPs) doped with Ce³⁺ ions were synthesized by a solvothermal method and used for cell-imaging. The crystallite sizes and photoluminescence spectra were tuned by lanthanide ions (Gd³⁺, Ce³⁺) doping. Without any surface modification, the YAG:Ce NPs show good water solubility, colloid stability and low toxicity. The intracellular uptake of the YAG:Ce NPs was visualized using a confocal fluorescence microscope under the excitation of a 457 nm laser due to the strong absorption of fluorescent NPs in the blue region. The non-bleaching property was confirmed by comparing with organic dye Alexa488. Overall, we demonstrated that the YAG:Ce NPs can serve as an efficient fluorescence imaging agent with visible light excitation and without photo-bleaching, which shows great foreground in bio-imaging, especially with confocal imaging system for in vitro studies.