Self-Sterilizing Laser-Induced Graphene Bacterial Air Filter

Abstract

Nosocomial infections transmitted through airborne, droplet, aerosol, and particulate-transported modes pose substantial infection risks to patients and healthcare employees. In this study, we demonstrate a self-cleaning filter comprised of laser-induced graphene (LIG), a porous conductive graphene foam formed through photothermal conversion of a polyimide film by a commercial CO₂ laser cutter. LIG was shown to capture particulates and bacteria. The bacteria cannot proliferate even when submerged in culture medium. Through a periodic Joule-heating mechanism, the filter readily reaches >300 °C. This destroys any microorganisms including bacteria, along with molecules that can cause adverse biological reactions and diseases. These molecules include pyrogens, allergens, exotoxins, endotoxins, mycotoxins, nucleic acids, and prions. Capitalizing on the high surface area and thermal stability of LIG, the utility of graphene for reduction of nosocomial infection in hospital settings is suggested.

Keywords: Joule heating; bacterial filter; laser-induced graphene; particulate filter; self-cleaning filter.