Electrical capture and lysis of vaccinia virus particles using silicon nano-scale probe array

A probe array with nano-scale tips, integrated into a micro-fluidic channel was developed for the capture and lysing of small number of vaccinia virus particles using dielectrophoresis. The nano-scale probe array was fabricated in Silicon on Insulator (SOI) wafers, and sharpened with repeated oxidation steps. The gap between each probe ranged from 100 nm to 1.5 μm depending on fabrication parameters. The probe array was used to capture vaccinia virus using positive dielectrophoresis (DEP) from a flow within the microfluidic channel, and then the same probe array was used to apply high electric field to lyse the virus particles. It was shown that under electric field strengths of about 10⁷V/m, the permeability of ethidium bromide into the vaccinia virus particles was increased. Upon SEM analysis, the particles were found to be damaged and exhibited tubules networks, indicating disintegration of the virus outer layer. In addition, elongated strands of DNA were clearly observed on the chip surface after the application of the high electric field, demonstrating the possibility of electrical lysis of virus particles.