Plasma treatment constitutes an efficient method for chemical-free disinfection.A spray-based system for dispensing plasma-activated aerosols onto surfaces would facilitate disinfection of complex and/or hidden surfac...Plasma treatment constitutes an efficient method for chemical-free disinfection.A spray-based system for dispensing plasma-activated aerosols onto surfaces would facilitate disinfection of complex and/or hidden surfaces inaccessible to direct line-of-sight(for example,UV)methods.The complexity and size of current plasma generators(for example,plasma jet and cometary plasma systems)-which prohibit portable operation,together with the short plasma lifetimes,necessitate a miniaturized in situ technique in which a source can be simultaneously activated and administered on-demand onto surfaces.Here,we demonstrate this possibility by combining two nanoscale technologies for plasma and aerosol generation into an integrated device that is sufficiently small and lightweight.Plasma is generated on a carpet of zinc oxide nanorods comprising a nanoneedle ensemble,which when raised to a high electric potential,constitutes a massive point charge array with near-singular electric fields to effect atmospheric breakdown.The plasma is then used to activate water transported through an underlying capillary wick,that is subsequently aerosolized under MHz-order surface acoustic waves.We show that the system,besides being amenable to miniaturization and hence integration into a chipscale device,leads to a considerable improvement in plasma-activation over its macroscale cometary discharge predecessor,with up to 20%and 127%higher hydrogen peroxide and nitrite ion concentrations that are respectively generated in the plasma-activated aerosols.This,in turn,leads to a 67%reduction in the disinfection time to achieve 95%bacterial load reduction,therefore demonstrating the potential of the technology as an efficient portable platform for on-demand field-use surface disinfection.展开更多
基金M.K.T.gratefully acknowledges funding for this work from the Fundamental Research Grant Scheme,Ministry of Education,Malaysia,through Project Grant No.FRGS/1/2019/TK03/MUSM/02/1.
文摘Plasma treatment constitutes an efficient method for chemical-free disinfection.A spray-based system for dispensing plasma-activated aerosols onto surfaces would facilitate disinfection of complex and/or hidden surfaces inaccessible to direct line-of-sight(for example,UV)methods.The complexity and size of current plasma generators(for example,plasma jet and cometary plasma systems)-which prohibit portable operation,together with the short plasma lifetimes,necessitate a miniaturized in situ technique in which a source can be simultaneously activated and administered on-demand onto surfaces.Here,we demonstrate this possibility by combining two nanoscale technologies for plasma and aerosol generation into an integrated device that is sufficiently small and lightweight.Plasma is generated on a carpet of zinc oxide nanorods comprising a nanoneedle ensemble,which when raised to a high electric potential,constitutes a massive point charge array with near-singular electric fields to effect atmospheric breakdown.The plasma is then used to activate water transported through an underlying capillary wick,that is subsequently aerosolized under MHz-order surface acoustic waves.We show that the system,besides being amenable to miniaturization and hence integration into a chipscale device,leads to a considerable improvement in plasma-activation over its macroscale cometary discharge predecessor,with up to 20%and 127%higher hydrogen peroxide and nitrite ion concentrations that are respectively generated in the plasma-activated aerosols.This,in turn,leads to a 67%reduction in the disinfection time to achieve 95%bacterial load reduction,therefore demonstrating the potential of the technology as an efficient portable platform for on-demand field-use surface disinfection.
