Separation of Nanoparticles in Aqueous Multiphase Systems through Centrifugation

Ozge Akbulut†, Charles R. Mace†, Ramses V.Martinez†, Ashok A. Kumar‡, Zhihong Nie†, Matthew R. Patton†, and George M. Whitesides*†§

^† Departments of Chemistry and Chemical Biology,Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States

^‡ School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, Massachusetts 02138, United States

^§ Wyss Institute for Biologically Inspired Engineering,Harvard University, 60 Oxford Street, Cambridge, Massachusetts 02138, United States

 Kavli Institute for Bionano Science and Technology, Harvard University, 29 Oxford Street, Cambridge, Massachusetts 02138, United States

Nano Lett., Article ASAP

DOI: 10.1021/nl301452x

Publication Date (Web): June 5, 2012

Copyright © 2012 American Chemical Society

This paper demonstrates the use of aqueous multiphase systems (MuPSs) as media for rate-zonal centrifugation to separate nanoparticles of different shapes and sizes. The properties of MuPSs do not change with time or during centrifugation; this stability facilitates sample collection after separation. A three-phase system demonstrates the separation of the reaction products (nanorods, nanospheres, and large particles) of a synthesis of goldnanorods, and enriches the nanorods from 48 to 99% in less than ten minutes using a benchtop centrifuge.