Manipulation of bacteriophages with dielectrophoresis on carbon nanofiber nanoelectrode arrays

Abstract

This work describes efficient manipulation of bacteriophage virus particles using a nanostructured dielectrophoresis (DEP) device. The non-uniform electric field for DEP is created by utilizing a nanoelectrode array (NEA) made of vertically aligned carbon nanofibers (VACNFs) versus a macroscopic indium tin oxide electrode in a "points-and-lid" configuration integrated in a microfluidic channel. The capture of the virus particles has been systematically investigated versus the flow velocity, sinusoidal AC frequency, peak-to-peak voltage, and virus concentration. The DEP capture at all conditions is reversible and the captured virus particles are released immediately when the voltage is turned off. At the low virus concentration (8.9×10 4 pfu·ml −1 ), the DEP capture efficiency up to 60% can be obtained. The virus particles are individually captured at isolated nanoelectrode tips and accumulate linearly with time. Due to the comparable size, it is more effective to capture virus particles than larger bacterial cells with such NEA based DEP devices. This technique can be potentially utilized as a fast sample preparation module in a microfluidic chip to capture, separate, and concentrate viruses and other biological particles in small volumes of dilute solutions in a portable detection system for field applications.

Light induced DEP for immobilizing and orienting Escherichia coli bacteria

“…Among the several applications of the DEP technique in biology we focus the attention on the immobilization of microbial organisms where the study of the early stage development of biofilms is desirable [19][20][21]. In literature, it has been largely demonstrated that DEP through local micro/nano-electrodes allows a time dependent accumulation of bacteriophages; thus resulting an excellent technique not only to immobilize but also to concentrate microorganisms [22][23][24][25][26][27]. Recently, new DEP principles have been demonstrated based on electrode-free approaches that allow to realize devices with great versatility in terms of liquid/polymer patterning geometries.…”

A dielectrophoresis method to manipulate and monitor theShewanella oneidensis

“…9 In the nonuniform electric field, the polarized particle experiences a translational force, referred to as the DEP force, which is a function of the conductivity and permittivity of the particle and the surrounding media, and the frequency and spatial gradients of the magnitude of the applied electric field. 10 Since the first application of DEP on separation of living and dead cells was described by Pohl and Hawk in 1966, 11 DEP has been widely used in biology including eukaryotic and prokaryotic cell, 12 virus, 13 proteins and DNA. 14 With the help of inexpensive microfluidics and microfabricated electrode arrays, the technology is now rapidly and steadily developing into a powerful and flexible tool to characterize, 9 separate, 15 manipulate, 16 analyze 17 and monitor 18 a variety of biological specimens.…”