Dear Isaac,
Thanks for pointing out the publication. Indeed it might be a neat way to make the core particles (I might give it a try soon). What I noticed in the publication is that the MNPs are relatively large (~50-100 nm) which is bigger than what we get with the coprecipitation protocol. In principle, the co-precipitation is also quite quick (synthesis takes ~15 minutes in large scale), the part that takes the longest is washing. Nevertheless, it sounds like a simple way to make the core particles possibly even easier than with the coprep method.
Cheers,
T.