Using Chelating Chitosan Nanobeads and a Microfluidic-Microelectric Trap to Sort Lead(II) in a Continuous Bloodstream Flow

The sorting of Pb2+ ions in a bloodstream flow has been carried out by mixing the ions in a chitosan nanobeads aqua-solution and then using a chelating mechanism to selectively sponge them up. To obtain an efficient chelating reaction and chelating nanobeads that can be attracted and separated from the bloodstream flow, a microfluidic device that has a microchannel with electrodes has been designed and fabricated by a microelectromechanical process. A local dielectrophoretic force obtained from nonuniform electric fields was elected to manipulate the chelating nanobeads in a continuous bloodstream flow. The experimental studies indicate that the chelating nanobeads undergo a positive dielectrophoresis when suspended in a continuous flow (V = 0.035-0.2 m/s) and exposed to radio frequency/ac fields at 13.56 MHz frequency. In this device, the microchannel with electrodes provides a local dielectrophoretic field that is strong enough to manipulate and separate the chelating nanobeads in a continuous bloodstream flow. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3532771] All rights reserved.