Figure 1.

a) Cys‐PIMA‐PEG polymer ligand structure used for the water transfer of all NCs involved in this study. b) Schematic sketch of the CE reaction on the water‐dispersible NCs. c,f,i) TEM images of water‐dispersible NCs used for the CE reaction. d,g,l) DLS hydrodynamic sizes (in number weighted) before (black line) and after (red line) the partial (13%) Cu exchange reaction showed no change in size, indicating the absence of aggregation after CE. e,h,m) Elemental analysis to follow the partial CE reaction (13%): Cu, Se, S, Zn or Fe element quantification, after CE reactions, reported as a percentage of the initial elements on the NC fraction (Cu:ZnSe, Cu:ZnS, and Cu:CuFeS₂) and on the washing solutions (filtrate) after NCs separation for e) ZnSe, h) ZnS and m) CuFeS₂ NCs.