Facile synthesis of stable, water-soluble magnetic CoPt hollow nanostructures assisted by multi-thiol ligands

We report the synthesis of CoPt hollow nanostructures using a simple reduction method in aqueous solution in the presence of poly(methacrylic acid) pentaerythritol tetrakis (3-mercaptopropionate) (PMAA-PTMP) polymer or a mixture of O-[2-(3-mercaptopropionyl-amino)ethyl]-O′-methylpolyethylene glycol (PEG-SH) polymer and cysteine-cysteine-alanine-leucine-asparagine-asparagine (CCALNN) peptide ligands. The presence of the multi-thiol functional group of the ligands is essential for the formation of the hollow nanostructures and their perimeter size can be tuned within the range of 7–54 nm by changing peptide concentration or length of polymer. These hollow nanostructures are water-soluble and superparamagnetic at room temperature. They are stable in a wide range of pH from 1 to 10, high electrolyte concentration up to 2 M NaCl, and in cell culture medium which makes them have great potential to be utilised in biomedical applications.