Zinc sulfide nanoparticles: a mechanism of formation in aqueous solutions and optical properties

Synthesis of surface-modified quantum dots

“…The presence of such a shell leads to a decrease in the defectiveness of the crystal structure of the QD core and to an increase in fl uorescence quantum yield, with its values exceeding 70% at room temperature. 37 Paramagnetic QDs can be obtained by doping CdSe/ ZnS nanoparticles with manganese. 38 Screening by the core shell of a particle containing highly toxic compounds can considerably reduce their emission into the surrounding environment, which is important when using QDs for medical diagnostics.…”

“…Natural amino acids, especially sulfur-containing ones, are a promising class of surface modifi ers for transition metal chalcogenides, in particular zinc. 37,55 They are well soluble in water, form stable complexes with the Zn 2+ ion, and are readily available and inexpensive in comparison with most organic modifi ers. Amino acids have a stabilizing eff ect due to the presence of two functional groups with diff erent natures, which are able to coordinate with a fragment of the surface of a nanocrystal containing Zn 2+ in a wide pH range (Scheme 17).…”