A smartphone-based electroporation system with highly robust and low-voltage silicon nanopillar chips.

ABSTRACT

In this work, a novel smartphone-based electroporation (EP) system integrated with 3D scalable and robust gold-coated silicon-nanopillar Electroporation (Au-Si NP-EP) chip using projection photolithography is developed, for the first time, for both EP and electric cell lysing (ECL) at low voltages. Au-SiNP-EP chip consists of silicon nanopillars fabricated by using ASML stepper, Deep Reactive Ion Etching (DRIE) process and coated with a gold microelectrode. The silicon nanopillars were optimized based on theoretical analysis and numerical simulations to enhance the electrical field intensity and mechanical strength. The fabricated Au-SiNP-EP chips are tested with both permeable (Acridine Orange (AO) and impermeable (Propidium Iodide (PI)) molecules for HeLa cells at different volts (1-8 V) and pulse duration (1-9 µs). The fabricated chip achieved an optimized EP efficiency of 84.3% and cell viability of 81.4% at a much smaller voltage (4.5V) than reported planar electroporation (PEP) devices (8-100V). Compared with nanostructures-based devices (2-20 V), our devices show both higher mechanical strength and fabrication yield. Besides, a smartphone app integrated with a low-cost open-source portable Arduino-based system is developed to provide optimized electrical protocols for both EP and ECL. The electric cell lysing with ECL efficiency of 97.0% at 7 V and pulse duration of 9 ms has been successfully demonstrated. The experimental results show that the proposed smartphone-based EP system with Au-SiNP EP chips is promising for various applications, including intracellular delivery of various biomolecules, drugs, and release of DNA/RNA molecules from biological cells.