Field enhancement in microfluidic semiconductor nanowire array.

Area of Science:

• Microfluidics and Nanotechnology
• Biophysics and Molecular Diagnostics

Background:

• Microfluidic platforms with nanomaterials are crucial for accelerating biological sample preparation and molecular diagnostics.
• Generating high electric fields for cell membrane electroporation within microfluidic channels remains a significant challenge.

Purpose of the Study:

• To investigate a novel mechanism for generating high electric fields in microfluidic channels using semiconductor nanowire arrays.
• To compare the electric field enhancement and cell lysis efficiency of different nanowire materials (ZnO, Si, Si-SiO2).

Main Methods:

• Fabrication and characterization of microfluidic channels integrated with semiconductor nanowire arrays (ZnO, Si, Si-SiO2).
• Application of electrostatic fields across nanowire arrays to measure localized electric field strengths.
• Analysis of E. coli cell trajectories and lysis probability within the microfluidic channels under varying electric fields and nanowire spacings.

Main Results:

• Semiconductor nanowire arrays significantly localize electric fields, achieving higher strengths than previously reported micro-geometries.
• ZnO nanowire arrays exhibit nearly 30 times greater electric field enhancement compared to Si or Si-SiO2 arrays due to unique geometry and material properties.
• ZnO nanowire arrays demonstrate a greater probability of E. coli cell lysis at comparable applied electric fields and inter-nanowire spacings.

Conclusions:

• Semiconductor nanowire arrays, particularly ZnO, are effective in generating localized high electric fields for enhanced electroporation in microfluidics.
• The findings provide detailed correlations between cell lysis probability, nanowire spacing, and applied electric field, optimizing platforms for molecular diagnostics.