With Prof. Jon Zubieta at SU we are exploring an interesting self-assembly system.  Using polyoxometalates clusters (POMs, also called Keplerates). Since each POM, depending on synthesis and counter ion, has a discrete size (~2nm) and charge (anionic). These can be used to electrostatically assemble positively charged AuNPs (~5nm).   Since these POMs are comparable in size to the NP, the self-assembly rate and phase behavior is due to charge balance in the nanosystem, and coulombic interactions. Working with graduate student Jonathan Gooch, we have been able to show the proof-of-principle of this approach, and those reports will be reported soon.