Manipulation of bacteriophages with dielectrophoresis on carbon nanofiber nanoelectrode arrays

This work describes efficient manipulation of bacteriophage virus particles using a nanostructured DEP device. The nonuniform electric field for DEP is created by utilizing a nanoelectrode array (NEA) made of vertically aligned carbon nanofibers 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), 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.