17 research outputs found
Laser-Induced Graphene Capacitive Killing of Bacteria
Laser-induced graphene (LIG) is a
method of generating a foam-like
conformal carbon layer of porous graphene on many types of carbon-based
surfaces. This electrically conductive material has been shown to
be useful in many applications including environmental technology
and includes low fouling and antimicrobial surfaces and can address
persistent environmental challenges spawned by bacterial and viral
contaminates. Here, we show that a single film of LIG stores charge
when an electrical current is applied and dissipates charge when the
current is stopped, which results in electricidal surface antibacterial
potency. The amount of accumulated and dissipated charge on a single
strip of LIG was quantified with an electrometer by generating LIG
on both sides of a nonconducting polyimide film, which showed up to
65 pC of charge when the distance between the surfaces was 94 μm
corresponding to an areal capacitance of 1.63 pF/cm2. We
further corroborate the stored charge decay of a single LIG strip
with bacteria death via direct electrical contact. Antimicrobial rates
decreased with the same monotonic pattern as the loss of charge from
the LIG film (i.e., AR ∼ 97% 0 s after voltage source disconnection
vs AR ∼ 21% 90 s after disconnection) showing bacterial death
as a function of delayed LIG exposure time after applied voltage disconnection.
In terms of energy efficiency, this translates to an increased bacteria
potency of ∼170% for the equivalent energy costs as that previously
estimated. Finally, we present a mechanistic explanation for the capacitive
behavior and the electricidal effects for a single plate of LIG
Laser-Induced Graphene Capacitive Killing of Bacteria
Laser-induced graphene (LIG) is a
method of generating a foam-like
conformal carbon layer of porous graphene on many types of carbon-based
surfaces. This electrically conductive material has been shown to
be useful in many applications including environmental technology
and includes low fouling and antimicrobial surfaces and can address
persistent environmental challenges spawned by bacterial and viral
contaminates. Here, we show that a single film of LIG stores charge
when an electrical current is applied and dissipates charge when the
current is stopped, which results in electricidal surface antibacterial
potency. The amount of accumulated and dissipated charge on a single
strip of LIG was quantified with an electrometer by generating LIG
on both sides of a nonconducting polyimide film, which showed up to
65 pC of charge when the distance between the surfaces was 94 μm
corresponding to an areal capacitance of 1.63 pF/cm2. We
further corroborate the stored charge decay of a single LIG strip
with bacteria death via direct electrical contact. Antimicrobial rates
decreased with the same monotonic pattern as the loss of charge from
the LIG film (i.e., AR ∼ 97% 0 s after voltage source disconnection
vs AR ∼ 21% 90 s after disconnection) showing bacterial death
as a function of delayed LIG exposure time after applied voltage disconnection.
In terms of energy efficiency, this translates to an increased bacteria
potency of ∼170% for the equivalent energy costs as that previously
estimated. Finally, we present a mechanistic explanation for the capacitive
behavior and the electricidal effects for a single plate of LIG