A Highly Robust Silicon Nano-pillar Chip for Electroporation Chip for Delivering Molecules to HeLa Cells

Electroporation (EP) is one of key bio-techniques for delivery of molecules to different types of cells, which uses the pulsed electric field to increase the permeability of cell membranes for drug delivery and DNA transfection because of its high cell viability and efficiency. Up to now, the researcher proposed micro/nanotechnology for electroporation (EP). The aluminum nano-spike EP (ANS-EP) chip has been fabricated for the small molecule delivery under a low applied voltage. However, the nano-spike on the chip is highly deformable and highly chemically reactive. We propose a novel gold-coated silicon nano-pillar electroporation (Au-SiNP-EP) chip to improve the mechanical strength of EP chips. COMSOL, electric field numerical simulations, indicated that the electric field enhancement, especially near the tips of Au-SiNP EP chip because of low-macroscopic-field emission (LMFE). Au-SiNP-EP chips were fabricated by projection photolithography, etching, and sputtering processes. The optimized protocol of Au-SiNP-EP chip using HeLa cells only requires the applied voltage of 3V using digital fluorescence microscopy with Acridine Orange (AO) and Propidium Iodide (PI) dyes. In summary, comparing to ANS-EP chips, the low-voltage Au-SiNP-EP chip with high mechanical strength is promising for large-scale high-throughput EP for molecular delivery to cells.