Detection of dielectrophoretic driven passage of single cells through micro-apertures in a silicon nitride membrane

Silicon (Si) microstructures are fabricated comprising a micro-aperture (10-25 microm) in a 1.2 kA silicon nitride membrane connecting two microfluidic compartments. Dielectrophoretic forces are created on-chip, which guide the passage of single CHO cells through the microaperture. When a cell dielectrophoretically traverses the aperture, there is a decrease in the background ionic current. These current fluctuations are recorded under varying cell concentrations, micro-aperture sizes, and applied voltages. This work shows the feasibility of building silicon-based bioparticle detectors with nanoscale apertures for sensing the translocation of cells, proteins, and even single-stranded DNA.