Chitosan Clad Manganese Doped Zinc Suiphide Nanoparticles as Biological Labels

Here the authors report the synthesis in aqueous media of redispersible zinc sulphide quantum dots doped with manganese, capped by biocompatible ´chitosan´ molecules. The nanoparticles show highly efficient luminescence with a peak at around 590 nm that has been correlated to the manganese dopants. The synthesis involves very simple precipitation techniques that may lead to the development of a cost effective alternative of using nanocrystals to replace fluorophores for biological staining. The biocompatible capping agent, chitosan, renders the particles suitable for bio-labels (markers). The 40 nm sized spherical nanoparticles consists of multiple crystallites of about 4-5 nm as observed in high resolution transmission electron microscopy studies.