Siyabonga ngokuvakashela i-Nature.com. Inguqulo yesiphequluli oyisebenzisayo inokusekelwa okulinganiselwe kwe-CSS. Ukuze uthole ulwazi olungcono kakhulu, sincoma ukuthi usebenzise isiphequluli esibuyekeziwe (noma ukhubaze i-Compatibility Mode ku-Internet Explorer). Okwamanje, ukuqinisekisa ukwesekwa okuqhubekayo, sizonikeza isayithi ngaphandle kwezitayela kanye ne-JavaScript.
I-carousel ebonisa amaslayidi amathathu ngesikhathi esisodwa. Sebenzisa izinkinobho Zangaphambilini kanye Nezilandelayo ukuze udlule kumaslayidi amathathu ngesikhathi, noma sebenzisa izinkinobho zesilayidi ekugcineni ukuze udlule kumaslayidi amathathu ngesikhathi.
Muva nje, kuthuthukiswe ipulatifomu engenamakhemikhali yokulwa namagciwane esekelwe kubuchwepheshe be-nanotechnology esebenzisa izakhiwo zamanzi ezenziwe ngokwenziwa (i-EWNS). I-EWNS ineshaja ephezulu ebusweni futhi igcwele izinhlobo ze-reactive oxygen (i-ROS) ezingasebenzisana futhi zivimbele inani lamagciwane, okuhlanganisa nezifo ezitholakala ekudleni. Lapha kuboniswa ukuthi izakhiwo zazo ngesikhathi sokwenziwa zingalungiswa kahle futhi zilungiselelwe ukuthuthukisa amandla azo okulwa namagciwane. Ipulatifomu yelabhorethri ye-EWNS yaklanywa ukuze ilungise izakhiwo ze-EWNS ngokushintsha amapharamitha okwenziwa. Ukucaciswa kwezakhiwo ze-EWNS (ishaja, usayizi kanye nokuqukethwe kwe-ROS) kusetshenziswa izindlela zesimanje zokuhlaziya. Ngaphezu kwalokho, zahlolwa amandla azo okuvimbela amagciwane ngokumelene namagciwane atholakala ekudleni njenge-Escherichia coli, i-Salmonella enterica, i-Listeria innocuous, i-Mycobacterium paraaccidentum kanye ne-Saccharomyces cerevisiae. Imiphumela evezwe lapha ikhombisa ukuthi izakhiwo ze-EWNS zingalungiswa kahle ngesikhathi sokwenziwa, okuholela ekwandeni okukhulu ekusebenzeni kahle kokungasebenzi. Ikakhulukazi, ishaja ephezulu yanda ngesilinganiso samane kanti izinhlobo ze-reactive oxygen zanda. Izinga lokususwa kwamagciwane lalincike kumagciwane futhi lalisukela ku-1.0 kuya ku-3.8 log ngemuva kokuchayeka imizuzu engu-45 kumthamo we-aerosol ongu-40,000 #/cc EWNS.
Ukungcola kwamagciwane kuyimbangela eyinhloko yezifo ezibangelwa ukudla okubangelwa ukungenwa kwamagciwane noma ubuthi bawo. E-United States kuphela, izifo ezibangelwa ukudla zibangela izifo ezingaba yizigidi ezingu-76, ukungeniswa esibhedlela okungu-325,000, kanye nokufa okungu-5,000 minyaka yonke1. Ngaphezu kwalokho, uMnyango Wezolimo wase-United States (i-USDA) ulinganisela ukuthi ukusetshenziswa okwengeziwe kwemikhiqizo emisha kubangelwa u-48% wazo zonke izifo ezibikwayo ezibangelwa ukudla e-United States2. Izindleko zesifo nokufa okubangelwa amagciwane abangelwa ukudla e-United States ziphakeme kakhulu, kulinganiselwa yi-Centers for Disease Control and Prevention (CDC) ezingaphezu kuka-US$15.6 billion ngonyaka3.
Njengamanje, ukungenelela kwamakhemikhali, imisebe5 kanye namagciwane okushisa6 ukuqinisekisa ukuphepha kokudla kwenziwa kakhulu ezindaweni zokulawula ezibalulekile (ama-CCP) ochungechungeni lokukhiqiza (ngokuvamile ngemva kokuvuna kanye/noma ngesikhathi sokupakisha) kunokuba kwenziwe njalo. Ngakho-ke, zivame ukungcoliswa. 7. Ukulawulwa okungcono kwezifo ezibangelwa ukudla kanye nokonakala kokudla kudinga ukungenelela kwamagciwane okungasetshenziswa kuyo yonke i-continuum yepulazi netafula ngenkathi kunciphisa umthelela wemvelo kanye nezindleko.
Muva nje, kuthuthukiswe ipulatifomu yokulwa namagciwane engenamakhemikhali, esekelwe ku-nanotechnology engavimba amabhaktheriya angaphezulu nawasemoyeni kusetshenziswa izakhiwo zamanzi ezenziwe ngokwenziwa (i-EWNS). I-EWNS yakhiqizwa kusetshenziswa izinqubo ezimbili ezifanayo, i-electrospray kanye ne-ionization yamanzi (Isithombe 1a). Izifundo zangaphambilini zikhombisile ukuthi i-EWNS inesethi ehlukile yezakhiwo zomzimba nezebhayoloji8,9,10. I-EWNS inesilinganiso sama-electron ayi-10 ngesakhiwo ngasinye kanye nosayizi wesilinganiso sama-nanoscale angu-25 nm (Isithombe 1b,c)8,9,10. Ngaphezu kwalokho, i-electron spin resonance (ESR) ikhombisile ukuthi i-EWNS iqukethe inani elikhulu lezinhlobo ze-oxygen ezisabelayo (i-ROS), ikakhulukazi i-hydroxyl (OH•) kanye ne-superoxide (O2-) radicals (Isithombe 1c)8. I-EVNS isemoyeni isikhathi eside futhi ingashayisana nama-microorganisms amiswe emoyeni futhi abe khona ebusweni, ilethe umthwalo wawo we-ROS futhi ibangele ukungasebenzi kwama-microorganisms (Isithombe 1d). Lezi zifundo zokuqala zikhombisile nokuthi i-EWNS ingasebenzisana futhi ivimbele amagciwane ahlukahlukene angenayo i-gram kanye ne-gram, okuhlanganisa ne-mycobacteria, ezindaweni nasemoyeni. I-transmission electron microscopy ibonise ukuthi ukungasebenzi kwabangelwa ukuphazamiseka kwe-membrane yeseli. Ngaphezu kwalokho, izifundo zokuphefumula ngokushesha zikhombisile ukuthi imithamo ephezulu ye-EWNS ayibangeli ukulimala kwamaphaphu noma ukuvuvukala 8.
(a) I-Electrospray yenzeka lapho kusetshenziswa i-voltage ephezulu phakathi kwepayipi le-capillary eliqukethe uketshezi kanye ne-counter electrode. (b) Ukusetshenziswa komfutho ophezulu kuphumela ezimweni ezimbili ezahlukene: (i) ukufutha amanzi ngogesi kanye (ii) ukwakheka kwezinhlobo ze-oxygen (ama-ion) ezibambeke ku-EWNS. (c) Isakhiwo esiyingqayizivele se-EWNS. (d) Ngenxa yemvelo yazo encane, i-EWNS iyakwazi ukuhambahamba kakhulu futhi ingasebenzisana nezifo ezibangelwa amagciwane emoyeni.
Ikhono leplatifomu ye-EWNS yokulwa namagciwane lokumisa ama-microorganisms atholakala ekudleni phezu kokudla okusha nalo liboniswe muva nje. Kuye kwaboniswa nokuthi ishaja ephezulu ye-EWNS ehlanganiswe nensimu kagesi ingasetshenziswa ukufeza ukulethwa okuqondiwe. Ngaphezu kwalokho, imiphumela yokuqala yamatamatisi aphilayo ngemuva kokuchayeka imizuzu engama-90 ku-EWNS engaba ngu-50,000 #/cm3 yayikhuthaza, kanti ama-microorganisms ahlukahlukene atholakala ekudleni njenge-E. coli ne-Listeria 11 abonile. Ngaphezu kwalokho, ukuhlolwa kokuqala kwe-organoleptic akubonisanga miphumela yokuzwa uma kuqhathaniswa namatamatisi okulawula. Nakuba le miphumela yokuqala yokumisa ikhuthaza ukusetshenziswa kokuphepha kokudla ngisho nasemithini ephansi kakhulu ye-EWNS engu-50,000#/cc. bheka, kusobala ukuthi amandla aphezulu okuvimbela angaba wusizo kakhulu ekunciphiseni ingozi yokutheleleka kanye nokonakala.
Lapha, sizogxila ocwaningweni lwethu ekuthuthukisweni kwepulatifomu yokukhiqiza i-EWNS ukuze sikwazi ukulungisa kahle amapharamitha okwenziwa kanye nokwenza ngcono izakhiwo ze-physicochemical ze-EWNS ukuze kuthuthukiswe amandla azo okulwa namagciwane. Ikakhulukazi, ukwenza ngcono kugxile ekwandiseni ukushaja kwendawo yazo (ukuthuthukisa ukulethwa okuqondiwe) kanye nokuqukethwe kwe-ROS (ukuthuthukisa ukusebenza kahle kokungasebenzi). Chaza izakhiwo ze-physico-chemical ezilungiselelwe (usayizi, ukushaja kanye nokuqukethwe kwe-ROS) usebenzisa izindlela zesimanje zokuhlaziya bese usebenzisa izinto ezincane zokudla ezifana ne-E.
I-EVNS yakhiwe ngokufafaza ngogesi kanyekanye kanye nokufaka amanzi ahlanzekile aphezulu (18 MΩ cm–1). I-nebulizer kagesi 12 ivame ukusetshenziselwa ukwenza uketshezi lube yi-atomization kanye nokuhlanganiswa kwezinhlayiya ze-polymer neze-ceramic 13 kanye nemicu 14 yobukhulu obulawulwayo.
Njengoba kuchaziwe ezincwadini zangaphambilini 8, 9, 10, 11, ekuhlolweni okuvamile, kwasetshenziswa i-voltage ephezulu phakathi kwe-capillary yensimbi kanye ne-counter electrode egxilile. Phakathi nale nqubo, kwenzeka izenzakalo ezimbili ezahlukene: i) i-electrospray kanye ne-ii) i-ionization yamanzi. Insimu kagesi enamandla phakathi kwama-electrode amabili ibangela ukuthi kube nokushaja okungekuhle ebusweni bamanzi ahlanganisiwe, okuholela ekwakhekeni kwama-cone e-Taylor. Ngenxa yalokho, kwakheka amaconsi amanzi ashajwe kakhulu, aqhubeka nokuqhekeka abe yizinhlayiya ezincane, njengase-Rayleigh theory16. Ngesikhathi esifanayo, amasimu kagesi aqinile abangela ukuthi amanye ama-molecule amanzi ahlukane futhi asuse ama-electron (ionize), okuholela ekwakhekeni kwenani elikhulu lezinhlobo ze-oxygen ezisebenzayo (ROS)17. I-ROS18 ekhiqizwe ngasikhathi sinye ihlanganiswe ku-EWNS (Isithombe 1c).
Kumfanekiso 2a kukhombisa uhlelo lokukhiqiza i-EWNS olwakhiwe futhi lwasetshenziswa ekuhlanganisweni kwe-EWNS kulolu cwaningo. Amanzi ahlanziwe agcinwe ebhodleleni elivaliwe afakwa ngethubhu le-Teflon (ububanzi bangaphakathi obungu-2 mm) aye enalitini yensimbi engagqwali engu-30G (i-capillary yensimbi). Ukugeleza kwamanzi kulawulwa umfutho womoya ngaphakathi ebhodleleni, njengoba kuboniswe kuMfanekiso 2b. Inaliti ifakwe ku-console ye-Teflon futhi ingalungiswa ngesandla iye ebangeni elithile ukusuka ku-electrode yekhawunta. I-electrode yekhawunta iyidiski ye-aluminium epholishiwe enembobo maphakathi ukuze kuthathwe isampula. Ngaphansi kwe-electrode yekhawunta kukhona i-funnel yesampula ye-aluminium, exhunywe kokunye ukusethwa kokuhlola nge-port yesampula (Umfanekiso 2b). Ukuze kugwenywe ukwakheka kweshaja okungaphazamisa ukusebenza kwesampula, zonke izingxenye zesampula zisekelwe ngogesi.
(a) Uhlelo Lokukhiqiza Isakhiwo Samanzi Esinobunjiniyela (i-EWNS). (b) Ingxenye yesampula kanye ne-electrospray, ekhombisa amapharamitha abaluleke kakhulu. (c) Ukusethwa kokuhlola kokungasebenzi kwamagciwane.
Uhlelo lokukhiqiza i-EWNS oluchazwe ngenhla luyakwazi ukushintsha amapharamitha okusebenza abalulekile ukuze kube lula ukulungisa kahle izakhiwo ze-EWNS. Lungisa i-voltage esetshenzisiwe (V), ibanga eliphakathi kwenaliti ne-electrode ephikisayo (L), kanye nokugeleza kwamanzi (φ) nge-capillary ukuze kulungiswe kahle izici ze-EWNS. Uphawu olusetshenziswa ukumela inhlanganisela ehlukene: [V (kV), L (cm)]. Lungisa ukugeleza kwamanzi ukuze uthole ikhoni ye-Taylor ezinzile yesethi ethile [V, L]. Ngenhloso yalolu cwaningo, ububanzi bokuvuleka kwe-electrode ephikisayo (D) bugcinwe ku-0.5 inches (1.29 cm).
Ngenxa ye-geometry elinganiselwe kanye ne-asymmetry, amandla ensimu kagesi awakwazi ukubalwa kusukela ezimisweni zokuqala. Esikhundleni salokho, isofthiwe ye-QuickField™ (Svendborg, Denmark)19 yasetshenziswa ukubala insimu kagesi. Insimu kagesi ayifani, ngakho-ke inani lensimu kagesi esiqongweni se-capillary lasetshenziswa njengenani lokubhekisela ekucushweni okuhlukahlukene.
Ngesikhathi socwaningo, kwahlolwa inhlanganisela eziningana ze-voltage kanye nebanga phakathi kwenaliti kanye ne-counter electrode ngokuya ngokwakheka kwe-Taylor cone, ukuzinza kwe-Taylor cone, ukuzinza kokukhiqizwa kwe-EWNS, kanye nokuphindaphinda. Inhlanganisela ehlukahlukene iboniswe kuThebula Elingeziwe S1.
Umphumela wohlelo lokukhiqiza i-EWNS uxhunywe ngqo ku-Scanning Mobility Particle Size Analyzer (SMPS, Model 3936, TSI, Shoreview, MN) ukuze kulinganiswe ukuhlushwa kwenombolo yezinhlayiya, kanye ne-Aerosol Faraday Electrometer (TSI, Model 3068B, Shoreview, MN). ) yemisinga ye-aerosol ilinganiswe njengoba kuchaziwe encwadini yethu yangaphambilini. Kokubili i-SMPS kanye ne-aerosol electrometer kuthathwe amasampula ngesilinganiso sokugeleza esingu-0.5 L/min (ukugeleza kwesampula okuphelele okungu-1 L/min). Ukuhlushwa kwenombolo yezinhlayiya kanye nokugeleza kwe-aerosol kulinganiswe imizuzwana engu-120. Ukulinganiswa kuphindaphindwa izikhathi ezingu-30. Ngokusekelwe ekulinganisweni kwamanje, inani eliphelele le-aerosol liyabalwa futhi inani elijwayelekile le-EWNS lilinganiswe enanini elinikeziwe lezinhlayiya ezikhethiwe ze-EWNS. Izindleko ezimaphakathi ze-EWNS zingabalwa kusetshenziswa i-Equation (1):
lapho i-IEl ingumshini olinganisiwe, i-NSMPS ingukuhlushwa kwedijithali okulinganiswe nge-SMPS, kanti i-φEl iyisilinganiso sokugeleza nge-electrometer ngayinye.
Ngenxa yokuthi umswakama ohlobene (RH) uthinta ukushaja kobuso, izinga lokushisa kanye (RH) kwagcinwa kungaguquguquki ngesikhathi sokuhlolwa ku-21°C kanye no-45%, ngokulandelana.
I-Atomic force microscopy (AFM), i-Asylum MFP-3D (Asylum Research, Santa Barbara, CA) kanye ne-AC260T probe (Olympus, Tokyo, Japan) zasetshenziswa ukukala usayizi kanye nesikhathi sokuphila kwe-EWNS. Imvamisa yokuskena ye-AFM yayingu-1 Hz, indawo yokuskena yayingu-5 μm × 5 μm, kanye nemigqa yokuskena engu-256. Zonke izithombe zafakwa ekulinganisweni kwesithombe se-oda lokuqala kusetshenziswa isofthiwe ye-Asylum (ibanga lemaski elingu-100 nm, umkhawulo ongu-100 pm).
I-funnel yokuhlola isusiwe futhi ubuso be-mica bubekwe ebangeni elingama-2.0 cm ukusuka ku-counter electrode isikhathi esimaphakathi samasekhondi angu-120 ukuze kugwenywe ukuhlangana kwezinhlayiya kanye nokwakheka kwamaconsi angajwayelekile ebusweni be-mica. I-EWNS yafuthwa ngqo ebusweni be-mica esanda kusikwa (Ted Pella, Redding, CA). Isithombe sobuso be-mica ngokushesha ngemva kokuchitheka kwe-AFM. I-engeli yokuxhumana yobuso be-mica esanda kusikwa engakashintshi iseduze no-0°, ngakho-ke i-EVNS isatshalaliswa ebusweni be-mica ngesimo se-dome. Ububanzi (a) kanye nokuphakama (h) kwamaconsi asakazekayo kwalinganiswa ngqo kusuka ku-topography ye-AFM futhi kwasetshenziswa ukubala ivolumu yokusabalala kwe-EWNS edome kusetshenziswa indlela yethu eqinisekisiwe ngaphambilini. Uma sicabanga ukuthi i-EWNS esebhodini inomthamo ofanayo, ububanzi obulinganayo bungabalwa kusetshenziswa i-Equation (2):
Ngokusekelwe endleleni yethu ethuthukisiwe ngaphambilini, kwasetshenziswa isicupho sokujikeleza se-electron spin resonance (ESR) ukuthola ukuthi kukhona ama-radical intermediates ahlala isikhathi esifushane ku-EWNS. Ama-aerosol afakwe ama-bubble ngokusebenzisa i-650 μm Midget sparger (Ace Glass, Vineland, NJ) equkethe isisombululo esingu-235 mM se-DEPMPO(5-(diethoxyphosphoryl)-5-methyl-1-pyrroline-N-oxide) (Oxis International Inc.). Portland, Oregon). Zonke izilinganiso ze-ESR zenziwe kusetshenziswa i-Bruker EMX spectrometer (Bruker Instruments Inc. Billerica, MA, USA) kanye neseli lephaneli eliyisicaba. Isofthiwe ye-Acquisit (Bruker Instruments Inc. Billerica, MA, USA) yasetshenziswa ukuqoqa nokuhlaziya idatha. Ukunqunywa kwezici ze-ROS kwenziwa kuphela kusethi yezimo zokusebenza [-6.5 kV, 4.0 cm]. Ukuhlushwa kwe-EWNS kwalinganiswa kusetshenziswa i-SMPS ngemuva kokubala ukulahlekelwa kwe-EWNS ku-impactor.
Amazinga e-Ozone aqashwe kusetshenziswa i-205 Dual Beam Ozone Monitor™ (2B Technologies, Boulder, Co)8,9,10.
Kuzo zonke izakhiwo ze-EWNS, inani elimaphakathi lisetshenziswa njengenani lokulinganisa, kanti ukuphambuka okujwayelekile kusetshenziswa njengephutha lokulinganisa. Ukuhlolwa kwe-T kwenziwe ukuze kuqhathaniswe amanani ezimfanelo ze-EWNS ezilungiselelwe namanani ahambisanayo esisekelo se-EWNS.
Isithombe 2c sibonisa uhlelo "lokudonsa" lwe-electrostatic precipitation (EPES) olwakhiwe ngaphambilini futhi oluchazwe ngaphambilini olungasetshenziswa ekulethweni okuqondiswe kulo kwe-EWNS ebusweni. I-EPES isebenzisa amashaja e-EVNS angaqondiswa ngqo ebusweni bethagethi ngaphansi kwethonya lensimu enamandla kagesi. Imininingwane yohlelo lwe-EPES ivezwe encwadini yakamuva kaPyrgiotakis et al. 11. Ngakho-ke, i-EPES inekamelo le-PVC eliphrintiwe nge-3D elineziphetho ezinciphile futhi liqukethe amapuleti amabili ensimbi engagqwali ahambisanayo (insimbi engagqwali engu-304, embozwe ngesibuko) enkabeni eqhelelene ngo-15.24 cm. Amabhodi axhunywe emthonjeni wangaphandle we-voltage ephezulu (Bertran 205B-10R, Spellman, Hauppauge, NY), ipuleti elingezansi lalihlala lixhunywe ku-voltage enhle, kanti ipuleti eliphezulu lalihlala lixhunywe emhlabathini (umhlabathi ontantayo). Izindonga zegumbi zimbozwe nge-aluminium foil, eqiniswe ngogesi ukuvimbela ukulahleka kwezinhlayiya. Ikamelo linomnyango wokulayisha wangaphambili ovaliwe ovumela izindawo zokuhlola ukuthi zibekwe ezitendini zepulasitiki eziziphakamisa ngaphezu kwepuleti lensimbi elingezansi ukuze kugwenywe ukuphazamiseka kwamandla kagesi aphezulu.
Ukusebenza kahle kokufakwa kwe-EWNS ku-EPES kubalwe ngokwephrothokholi eyathuthukiswa ngaphambilini echazwe ku-Supplementary Figure S111.
Njengegumbi lokulawula, igumbi lokugeleza lesibili eliyindilinga laxhunywa ngochungechunge ohlelweni lwe-EPES, lapho kwasetshenziswa khona isihlungi se-HEPA esiphakathi ukususa i-EWNS. Njengoba kuboniswe kuMfanekiso 2c, i-aerosol ye-EWNS yapontshwa ngamakamelo amabili akhelwe ngaphakathi. Isihlungi esiphakathi kwegumbi lokulawula ne-EPES sisusa noma yimaphi ama-EWNS asele okuholela ekushiseni okufanayo (T), umswakama ohlobene (RH) kanye namazinga e-ozone.
Kutholakale ukuthi ama-microorganisms abalulekile atholakala ekudleni angcolisa ukudla okusha njenge-E. coli (ATCC #27325), i-fecal indicator, i-Salmonella enterica (ATCC #53647), i-foodborne pathogen, i-Listeria engenabungozi (ATCC #33090), i-subrogate ye-pathogenic Listeria monocytogenes, etholakala ku-ATCC (Manassas, VA) Saccharomyces cerevisiae (ATCC #4098), okuyindawo yemvubelo yokubola, kanye ne-bacterium engasebenzi enamandla kakhulu, i-Mycobacterium paralucky (ATCC #19686).
Thenga amabhokisi angahleliwe katamatisi wamagilebhisi angokwemvelo emakethe yakini bese uwafaka efrijini ku-4°C kuze kube yilapho esetshenziswa (kuze kube yizinsuku ezi-3). Utamatisi ohloliwe wawulingana ngobukhulu, cishe u-1/2 intshi ububanzi.
Izinqubo zokukhuliswa, ukugonywa, ukuchayeka, kanye nokubalwa kwamakholoni zichazwe kabanzi encwadini yethu yangaphambilini futhi zichazwe kabanzi ku-Supplementary Data. Ukusebenza kahle kwe-EWNS kuhlolwe ngokudalula utamatisi ogonyiwe ku-40,000 #/cm3 imizuzu engama-45. Ngamafuphi, utamatisi abathathu basetshenziswa ukuhlola amagciwane asindayo ngesikhathi t = 0 min. Utamatisi abathathu bafakwa ku-EPES futhi bavezwa ku-EWNS ku-40,000 #/cc (utamatisi ovezwe yi-EWNS) kanti abathathu abasele bafakwa ekamelweni lokulawula (utamatisi wokulawula). Ukucutshungulwa okwengeziwe kotamatisi kuwo womabili amaqembu akwenziwanga. Utamatisi ovezwe yi-EWNS kanye notamatisi wokulawula basuswa ngemva kwemizuzu engama-45 ukuhlola umphumela we-EWNS.
Ukuhlolwa ngakunye kwenziwa kathathu. Ukuhlaziywa kwedatha kwenziwa ngokwephrothokholi echazwe kuDatha Engeziwe.
Izindlela zokungasebenzi zihlolwe ngokuthululwa kwamasampula e-EWNS avele (imizuzu engama-45 ekugxilweni kwe-aerosol ye-EWNS okungu-40,000 #/cm3) kanye namasampula angashiswanga yi-bacteria engenangozi i-E. coli, i-Salmonella enterica kanye ne-Lactobacillus. Izinhlayiya zaqiniswa ku-2.5% glutaraldehyde, i-1.25% paraformaldehyde kanye ne-0.03% picric acid ku-0.1 M sodium cacodylate buffer (pH 7.4) amahora ama-2 ekushiseni kwegumbi. Ngemva kokugeza, lungisa nge-1% osmium tetroxide (OsO4)/1.5% potassium ferrocyanide (KFeCN6) amahora ama-2, geza izikhathi ezi-3 emanzini bese ufaka ku-1% uranyl acetate ihora eli-1, bese ugeza kabili emanzini, bese ukhipha amanzi imizuzu eyi-10 ku-50%, 70%, 90%, 100% alcohol. Amasampula abe esefakwa ku-propylene oxide ihora eli-1 bese efakwa ingxube ye-propylene oxide engu-1:1 kanye ne-TAAP Epon (Marivac Canada Inc. St. Laurent, CA). Amasampula afakwa ku-TAAB Epon futhi afakwa i-polymer ku-60°C amahora angu-48. I-resin ehlanganisiwe elungisiwe yasikwa futhi yabonakala nge-TEM kusetshenziswa i-microscope evamile ye-transmission electron JEOL 1200EX (JEOL, Tokyo, Japan) ehlonyiswe ngekhamera ye-AMT 2k CCD (Advanced Microscopy Techniques, Corp., Woburn, Massachusetts, USA).
Zonke izivivinyo zenziwe kathathu. Ngephuzu ngalinye lesikhathi, ukuhlanza kwamagciwane kwahlwanyelwa kathathu, okwaholela engqikithini yamaphuzu edatha ayisishiyagalolunye ngephuzu ngalinye, isilinganiso sawo sasetshenziswa njengokuhlushwa kwamagciwane kwaleyo microorganism ethile. Ukuphambuka okujwayelekile kwasetshenziswa njengephutha lokulinganisa. Wonke amaphuzu abalwa.
I-logarithm yokwehla kokuhlushwa kwamagciwane uma kuqhathaniswa ne-t = 0 min ibalwa kusetshenziswa ifomula elandelayo:
lapho i-C0 ingukuhlushwa kwamabhaktheriya kusampula yokulawula ngesikhathi esingu-0 (okungukuthi ngemva kokuba ubuso bomile kodwa ngaphambi kokufakwa ekamelweni) kanye ne-Cn ingukuhlushwa kwamabhaktheriya ebusweni ngemva kwemizuzu engu-n yokuchayeka.
Ukuze kucatshangelwe ukuwohloka kwemvelo kwamagciwane ngesikhathi sokuchayeka kwemizuzu engama-45, ukuncishiswa kwelogi uma kuqhathaniswa nokulawula ngemva kwemizuzu engama-45 nakho kubalwe kanje:
lapho i-Cn ingukuhlushwa kwamagciwane kusampula yokulawula ngesikhathi i-n kanye ne-Cn-Control ingukuhlushwa kwamagciwane okulawula ngesikhathi i-n. Idatha yethulwa njengokunciphisa kwelogi uma kuqhathaniswa nokulawula (akukho ukuvezwa kwe-EWNS).
Ngesikhathi socwaningo, inhlanganisela eziningana ze-voltage kanye nebanga phakathi kwenaliti kanye ne-counter electrode yahlolwa ngokuya ngokwakheka kwe-Taylor cone, ukuzinza kwe-Taylor cone, ukuzinza kokukhiqizwa kwe-EWNS, kanye nokuzala kabusha. Inhlanganisela ehlukahlukene iboniswe kuThebula Elingeziwe S1. Amacala amabili abonisa izakhiwo ezizinzile neziphindaphindayo (i-Taylor cone, ukukhiqizwa kwe-EWNS, kanye nokuqina ngokuhamba kwesikhathi) akhethwe ukuze kufundwe kabanzi. Ku-Fig. Isithombe 3 sibonisa imiphumela yokushaja, usayizi, kanye nokuqukethwe kwe-ROS kuzo zombili izimo. Imiphumela iboniswe nakuThebula 1. Ukuze kubhekwe, zombili i-Figure 3 kanye neThebula 1 zifaka izakhiwo ze-EWNS8, 9, 10, 11 ezingazange zilungiselelwe ngaphambilini (baseline-EWNS). Izibalo zokubaluleka kwezibalo ezisebenzisa i-t-test enemisila emibili ziphinde zanyatheliswa kuThebula Elingeziwe S2. Ngaphezu kwalokho, idatha eyengeziwe ifaka phakathi izifundo zomphumela we-counter electrode sampling hole diameter (D) kanye nebanga phakathi kwe-ground electrode kanye ne-tip (L) (Izibalo Ezingeziwe S2 kanye ne-S3).
(ac) Ukusatshalaliswa kosayizi okulinganiswe yi-AFM. (df) Isici seshaja engaphezulu. (g) Ukucaciswa kwe-ROS kwe-EPR.
Kubalulekile futhi ukuqaphela ukuthi kuzo zonke izimo ezingenhla, ugesi we-ionization olinganisiwe wawuphakathi kuka-2 no-6 μA kanye ne-voltage ephakathi kuka--3.8 no--6.5 kV, okwaholela ekusetshenzisweni kwamandla okungaphansi kuka-50 mW kule module yokuxhumana yesizukulwane se-EWNS eyodwa. Nakuba i-EWNS yakhiwa ngaphansi komfutho ophezulu, amazinga e-ozone ayephansi kakhulu, engadluli ku-60 ppb.
Isithombe Esengeziwe S4 sibonisa amasimu kagesi alingisiwe ezimo ze-[-6.5 kV, 4.0 cm] kanye ne-[-3.8 kV, 0.5 cm], ngokulandelana. Ezimo ze-[-6.5 kV, 4.0 cm] kanye ne-[-3.8 kV, 0.5 cm], izibalo zensimu ziyi-2 × 105 V/m kanye ne-4.7 × 105 V/m, ngokulandelana. Lokhu kulindeleke, njengoba esimweni sesibili isilinganiso sebanga le-voltage siphezulu kakhulu.
Ku-fig. 3a,b kukhombisa ububanzi be-EWNS obulinganiswe nge-AFM8. Ububanzi obumaphakathi be-EWNS babungu-27 nm no-19 nm kuma-[-6.5 kV, 4.0 cm] kanye no-[-3.8 kV, 0.5 cm], ngokulandelana. Ezimweni ze-[-6.5 kV, 4.0 cm] kanye no-[-3.8 kV, 0.5 cm], ukuphambuka okujwayelekile kwe-geometric kokusatshalaliswa kungu-1.41 no-1.45, ngokulandelana, okubonisa ukusatshalaliswa kosayizi omncane. Kokubili ubukhulu obumaphakathi kanye nokuphambuka okujwayelekile kwe-geometric kuseduze kakhulu ne-baseline EWNS, ku-25 nm kanye no-1.41, ngokulandelana. Ku-fig. 3c kukhombisa ukusatshalaliswa kosayizi kwe-base EWNS okulinganiswe kusetshenziswa indlela efanayo ngaphansi kwezimo ezifanayo.
Ku-Fig. 3d, e kukhombisa imiphumela yokuchayeka kweshaja. Idatha iyizilinganiso ezimaphakathi zokulinganisa okungu-30 ngesikhathi esisodwa kokuhlushwa (#/cm3) kanye nogesi (I). Ukuhlaziywa kukhombisa ukuthi isilinganiso seshaja ku-EWNS singama-22 ± 6 e- kanye nama-44 ± 6 e- kuma-[-6.5 kV, 4.0 cm] kanye nama-[-3.8 kV, 0.5 cm], ngokulandelana. Anezindleko eziphezulu kakhulu zomphezulu uma kuqhathaniswa nama-baseline EWNS (10 ± 2 e-), amakhulu kabili kunesimo se-[-6.5 kV, 4.0 cm] kanye namakhulu amane kune-[-3 .8 kV, 0.5 cm]. Isibalo 3f sibonisa idatha yeshaja. ye-Baseline-EWNS.
Kusukela kumamephu okuhlushwa kwenombolo ye-EWNS (Izibalo Ezingeziwe S5 kanye ne-S6), kungabonakala ukuthi isimo se-[-6.5 kV, 4.0 cm] sinezinhlayiya eziningi kakhulu kunesimo se-[-3.8 kV, 0.5 cm]. Kubalulekile futhi ukuqaphela ukuthi ukuhlushwa kwenombolo ye-EWNS kwaqashwa kuze kube amahora ama-4 (Izibalo Ezingeziwe S5 kanye ne-S6), lapho ukuzinza kwesizukulwane se-EWNS kwabonisa amazinga afanayo okuhlushwa kwenombolo yezinhlayiya kuzo zombili izimo.
Ku-fig. 3g kukhombisa i-EPR spectrum ngemva kokukhipha ukulawula kwe-EWNS okulungiselelwe (ingemuva) ku-[-6.5 kV, 4.0 cm]. Ama-ROS spectra nawo aqhathaniswa nesimo se-Baseline-EWNS emsebenzini oshicilelwe ngaphambilini. Inani lama-EWNS asabela ngama-spin traps libalwe laba ngu-7.5 × 104 EWNS/s, okufana ne-Baseline-EWNS8 eshicilelwe ngaphambilini. Ama-EPR spectra abonise ngokusobala ukuba khona kwezinhlobo ezimbili ze-ROS, lapho i-O2- iyinhlobo evelele kanye ne-OH• incane kakhulu. Ngaphezu kwalokho, ukuqhathaniswa okuqondile kwamandla aphezulu kubonise ukuthi ama-EWNS alungiselelwe ayenokuqukethwe kwe-ROS okuphezulu kakhulu uma kuqhathaniswa ne-baseline EWNS.
Ku-fig. 4 kukhombisa ukusebenza kahle kokufakwa kwe-EWNS ku-EPES. Idatha ifingqiwe futhi kuThebula I futhi iqhathaniswa nedatha yokuqala ye-EWNS. Kuzo zombili izimo ze-EUNS, ukufakwa kuseduze no-100% ngisho noma ku-voltage ephansi engu-3.0 kV. Ngokuvamile, i-3.0 kV yanele ukufakwa okungu-100%, kungakhathaliseki ukushintsha kweshaja ebusweni. Ngaphansi kwezimo ezifanayo, ukusebenza kahle kokufakwa kwe-Baseline-EWNS kwakungu-56% kuphela ngenxa yokushaja kwabo okuphansi (isilinganiso sama-electron ayi-10 nge-EWNS ngayinye).
Ku-Fig. 5 kanye nasethebuleni. 2 kufingqa inani lokungasebenzi kwama-microorganisms afakwe phezu kotamatisi ngemuva kokuchayeka ku-40,000 #/cm3 EWNS imizuzu engama-45 ngemodi efanele [-6.5 kV, 4.0 cm]. I-E. coli efakwe kanye ne-Lactobacillus innocuous zibonise ukwehla okukhulu kwama-log angu-3.8 ngesikhathi sokuchayeka kwemizuzu engama-45. Ngaphansi kwezimo ezifanayo, i-S. enterica ibe nokwehla kwama-log angu-2.2, kuyilapho i-S. cerevisiae kanye ne-M. parafortutum zibe nokwehla kwama-log angu-1.0.
Ama-electron micrograph (Isithombe 6) abonisa izinguquko zomzimba ezibangelwa yi-EWNS kumaseli e-Escherichia coli angenangozi, i-Streptococcus, ne-Lactobacillus okuholele ekungasebenzini kwawo. Amabhaktheriya okulawula ayenezimbotshana zamaseli ezingaphelele, kuyilapho amabhaktheriya avele obala onakele izimbotshana zangaphandle.
Ukuthwebula izithombe ezincane ze-electron zokulawula kanye namabhaktheriya avele obala kwembule umonakalo we-membrane.
Idatha ngezakhiwo ze-physicochemical ze-EWNS ezilungiselelwe ndawonye ikhombisa ukuthi izakhiwo (i-surface charge kanye nokuqukethwe kwe-ROS) ze-EWNS zithuthuke kakhulu uma kuqhathaniswa nedatha eyisisekelo ye-EWNS eshicilelwe ngaphambilini8,9,10,11. Ngakolunye uhlangothi, usayizi wazo wahlala kububanzi be-nanometer, obufana kakhulu nemiphumela ebikwe ngaphambilini, okuvumela ukuthi zihlale emoyeni isikhathi eside. Ukusabalala kwe-polydispersity okubonwe kungachazwa ngezinguquko ze-surface charge ezinquma usayizi we-EWNS, ukungahleleki komphumela we-Rayleigh, kanye nokuhlangana okungenzeka. Kodwa-ke, njengoba kuchaziwe nguNielsen et al. 22, i-surface charge ephezulu inciphisa ukuhwamuka ngokwandisa ngempumelelo amandla/ukucindezelwa kwamanzi. Encwadini yethu yangaphambilini8 le mbono yaqinisekiswa ngokuhlola kwama-microdroplets 22 kanye ne-EWNS. Ukulahlekelwa yi-charge ngesikhathi se-overtime kungathinta nosayizi futhi kufake isandla ekusatshalalisweni kosayizi okubonwe.