Direct Generation of Mn‐Doped ZnS Quantum Dots/Alginate Nanocomposite Beads Based on Gelation and In Situ Synthesis of Quantum Dots.

Herein, a concise and novel method is developed to directly generate Mn‐doped ZnS QDs/alginate nanocomposite beads. In this method, the ionic gelation of alginate is employed to produce alginate gel beads in a solution of Zn2+ and Mn2+ ions. Subsequently, the gel beads serve as the reaction support for in situ synthesis of Mn‐doped ZnS QDs in the beads through the reaction of sodium sulfide with Zn2+ and Mn2+ ions. The method has many benefits such as the simple preparation, the environmentally friendly process, the mild conditions, and the easy post‐treatment for the beads. The resulting QDs/alginate beads are homogeneous and stable gel spheres which show clear fluorescence. TEM images demonstrate that Mn‐doped ZnS QDs are homogeneously distributed within the QDs/alginate nanocomposite, and their average size is 2.4 ± 0.3 nm. Potentially, the QDs/alginate beads can be utilized for fluorescence bioimaging, as well as fluorescence detection toward metal ions. In this work, a novel, concise, and convenient method, based on the ionic gelation of alginate and in situ synthesis of QDs, is developed to directly fabricate Mn‐doped ZnS QDs/alginate nanocomposite beads. The method offers benefits such as the simple operation, the environmentally friendly process, the mild conditions, and the easy separation and post‐treatment for the nanocomposite beads. [ABSTRACT FROM AUTHOR]