Synthesis of manganese-doped silver selenide quantum dots with near-infrared photoluminescent and paramagnetic properties

Water-dispersible Mn2+-doped Ag2Se QDs were synthesized by solvothermal reaction of silver and manganese salts with selenium source and subsequent ligand exchange. The Mn doping level could be tuned by changing the feed amount of the Mn precursor. The Mn2+-doped Ag2Se QDs had a crystal structure typical of monoclinic alpha-Ag2Se. At the Mn doping level of 0.28%, the photoluminescence quantum yield at 1130 nm remained at 5.7%. Moreover, EPR spectrum and VSM result suggest paramagnetic characteristics of the 0.28% doped QDs. Cytotoxicity test indicates good biocompatibility of the Mn2+-doped Ag2Se QDs, which have great potential for biomedical imaging. (C) 2018 Elsevier B.V. All rights reserved.