Operando Investigation of the Locally Enhanced Electric Field Treatment (LEEFT) Harnessing Lightning-Rod Effect for Rapid Bacteria Inactivation

Abstract

\n The growth of undesired bacteria causes numerous problems. Here, we show that locally enhanced electric field treatment (LEEFT) can cause rapid bacteria inactivation by electroporation without any side reactions. The bacteria inactivation is studied in situ at the single-cell level on a lab-on-a-chip that has nanowedge-decorated electrodes. Rapid bacteria inactivation occurs specifically at nanowedge tips where the electric field is enhanced due to the lightning-rod effect. The mechanism study shows that the bacteria inactivation is caused by electroporation induced by the locally enhanced electric field. The bacteria inactivation performance depends on the strength of the enhanced electric field instead of the applied voltage, and no ROS generation is detected when >90% bacteria inactivation is achieved. Quick membrane pore closure under moderate LEEFT indicates that electroporation is the predominant mechanism. LEEFT only requires facile treatment to achieve bacteria inactivation, which is safe for treating delicate samples and energy-efficient for large scale applications. The findings in this work can provide strong supports for the future applications of LEEFT.