A multiplexed separation of iron oxide nanocrystals using variable magnetic fieldsElectronic supplementary information (ESI) available. See DOI: 10.1039/c1nr10671f

The size-dependent magnetic properties of nanocrystals are exploited in a separation process that distinguishes particles based on their diameter. By varying the magnetic field strength, four populations of magnetic materials were isolated from a mixture. This separation is most effective for nanocrystals with diameters between 4 and 16 nm. Iron oxide nanocrystals are magnetically separated by size through the adjustment of magnetic field strength in a high-gradient magnetic separator.