Vortex-assisted, nanoarchitectonic manipulation of microparticles with flavonoid-Fe³⁺ complex in biphasic water–oil systems

Coordination-driven self-assembly of metal-ligand complexes is a powerful nanoarchitectonic tool for particle engineering, but its usability is limited when using two immiscible coating components. This paper reports that simple vortexing of a biphasic system of Fe3+ ions in water and flavonoids in oil forms nanoshells on individual particles, thereby enabling the utilization of water-insoluble ligands as coating materials. Mechanistic studies suggest that the biphasic mass-transfer equilibrium of flavonoid-Fe3+ species controls the shell formation, with the oil phase acting as a reservoir of coating precursors for continuous coating. The versatility and convenience of our method expand the chemical toolbox for modulating particle-material interfaces.