The growth of undesired bacteria can cause numerous problems. Seeking effective and sustainable inactivation approaches is an everlasting effort. Here, we show that nano-enhanced electric field treatment (NEEFT) can cause rapid bacteria inactivation with a lower applied voltage than bulk EFT. A lab-on-a-chip with nanowedge-modified electrodes is developed, and the bacteria inactivation in NEEFT is visualized and studied in real-time at a single-cell level. Rapid bacteria inactivation (~ 1 ms) occurs specifically at nanowedge tips where the electric field is enhanced due to the lightning-rod effect. Nanowedges with a high aspect ratio are critical for bacteria inactivation. NEEFT works for both immobilized and free-moving cells, where the free-moving cells will be first attracted to the nanowedge tips followed by rapid inactivation. The mechanism study shows that the bacteria inactivation is caused by electroporation induced by the nano-enhanced electric field. The bacteria inactivation performance depends on the strength of the enhanced electric field instead of the applied voltage. Quick pore closure and membrane recovery under moderate NEEFT indicate that electroporation is the predominant mechanism. NEEFT only requires facile treatment to achieve bacteria inactivation, which is safe for treating delicate samples and energy-efficient for large scale applications. It is also expected to find applications for targeted cell inactivation.

Nano-enhanced electric-field treatment harnessing lightning-rod effect for rapid bacteria inactivation

ACS Fall 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.