2016 Volume 24 Pages 98-102
There are no reports on liquid–liquid extraction of solid nanoparticles based on size- or surface- selective separation. In the present study, we examined phase-transfer of semiconductor nanoparticles in surface- and size- selective manners using reverse micelles and a DNA surfactant. We adopted DNA-functionalized CdTe quantum dots (DNA-QDs) as target solid nanoparticles. The DNA surfactant recognized DNA tethered to QDs and transferred the DNA-QDs to an organic phase via the DNA hybridization. These were successfully applied in the liquid–liquid extraction of DNA-QDs from an aqueous phase to an organic phase in both surface- and size-selective manners. I investigated the size-dependent extraction of the DNA-QDs from a mixture of DNA-QDs with different diameters (4 and 5.5 nm). These two types of DNA-QDs were added to an aqueous phase containing DNA surfactant, followed by the addition of an organic phase containing DLPC and 1-hexanol. Following gentle stirring for 3 h, DNA-QDs with QDs of size 4 nm were preferentially extracted over DNA-QDs with QDs of size 5.5 nm, which were barely extracted. Thus, the present system affords size-selective extraction of DNA-QDs from a mixture of DNA-QDs to an organic phase.