Nanoparticle analysis using microscale field flow fractionation

Abstract

Microscale electrical field flow fractionation (FFF) has shown significant progress since it was first reported in early 1997. The first electrical FFF systems were lucky to function for more than a few days and generated only minimal levels of retention and separation, while current systems now easily function for years and can generate multicomponent nanoparticle separations. A variety of microscale FFF systems have now been reported including: multiple versions of normal electrical FFF (ElFFF), cyclical electrical FFF (using oscillating fields), dielectrophoretic FFF, thermal FFF, and a combined thermal-electric FFF channel. Related microscale electrical SPLITT systems have also been demonstrated. Microscale ElFFF systems have been used to analyze and separate nanoparticles, DNA, proteins, cells, viruses, liposomes, large polymers, and other materials. ElFFF clearly improves upon system miniaturization due to the reduction in sample and carrier volumes, analysis times and more notably an increase in the separation resolution with a reduction in analysis times. Other advantages of miniaturized FFF include: parallel processing with multiple separation channels, batch fabrication with reduced costs, high quality manufacturing, and potentially disposable systems. Additionally, the possibility of on-chip sample injection, detection and signal processing favors the microfabrication of FFF systems.