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Kutshanje, iqonga elingenazo iikhemikhali zokulwa namagciwane elisekelwe kwi-nanotechnology esebenzisa ii-nanostructures zamanzi ezenziweyo (EWNS) liye laphuhliswa. Ii-EWNS zinombane ophezulu kwaye zigcwele iintlobo ze-oxygen (ROS) ezinokusebenzisana kwaye zivale inani lee-microorganisms, kuquka ne-pathogens ezifumaneka ngokutya. Apha kuboniswa ukuba iipropati zazo ngexesha lokwenziwa zinokulungiswa kwaye ziphuculwe ukuze ziphucule ngakumbi amandla azo okulwa namagciwane. Iqonga lelebhu ye-EWNS lenzelwe ukulungisa iipropati ze-EWNS ngokutshintsha iiparameter zokwenziwa. Ukuchazwa kweepropati ze-EWNS (umbane, ubungakanani kunye nomxholo we-ROS) kusetyenziswa iindlela zanamhlanje zohlalutyo. Ukongeza, zavavanywa amandla azo okungasebenzi kwee-microorganisms ngokuchasene nee-microorganisms ezifumaneka ngokutya ezifana ne-Escherichia coli, i-Salmonella enterica, i-Listeria innocuous, i-Mycobacterium paraaccidentum kunye ne-Saccharomyces cerevisiae. Iziphumo ezivezwe apha zibonisa ukuba iipropati ze-EWNS zinokulungiswa ngexesha lokwenziwa, nto leyo ekhokelela ekwandeni okukhulu ekusebenzeni kokungasebenzi. Ngokukodwa, umbane ophezulu unyuke nge-factor yesine kwaye iintlobo ze-oxygen ezisabelayo zanda. Izinga lokususwa kweentsholongwane lalixhomekeke kwiintsholongwane kwaye laliqala kwi-1.0 ukuya kwi-3.8 log emva kokuvezwa kwidosi ye-aerosol ye-40,000 #/cc EWNS imizuzu engama-45.
Ungcoliseko lweentsholongwane zezona zinto zibangela izifo ezibangelwa kukutya okubangelwa kukutya okubangelwa kukutya okubangelwa zizifo ezibangelwa ziintsholongwane okanye iityhefu zazo. E-United States kuphela, izifo ezibangelwa kukutya zibangela izifo ezimalunga nezigidi ezingama-76, ukungeniswa esibhedlele ezingama-325,000, kunye nokufa kwabantu abangama-5,000 minyaka le1. Ukongeza, iSebe lezoLimo lase-United States (i-USDA) liqikelela ukuba ukusetyenziswa kakhulu kwemveliso emitsha kubangele i-48% yazo zonke izifo ezichazwe njengezifo ezibangelwa kukutya e-United States2. Iindleko zezifo nokufa okubangelwa zizifo ezibangelwa kukutya e-United States ziphezulu kakhulu, ziqikelelwa yiZiko loLawulo lweZifo kunye nokuThintela (i-CDC) ngaphezulu kwe-US$15.6 yeebhiliyoni ngonyaka3.
Okwangoku, ukungenelela kwee-chemical4, i-radiation5 kunye ne-thermal6 antimicrobial ukuqinisekisa ukhuseleko lokutya kwenziwa ikakhulu kwiindawo zokulawula ezibalulekileyo (ii-CCP) kwikhonkco lemveliso (ngesiqhelo emva kokuvuna kunye/okanye ngexesha lokupakisha) endaweni yokuqhubeka. Ngenxa yoko, zinomngcipheko wokungcola okuhambahambayo. 7. Ulawulo olungcono lwezifo ezibangelwa kukutya kunye nokonakala kokutya kufuna ukungenelela kwee-antimicrobial okunokuthi kusetyenziswe kulo lonke ixesha lokuhamba kwefama ngelixa kunciphisa impembelelo kunye neendleko zokusingqongileyo.
Kutshanje, kuye kwaphuhliswa iqonga le-antimicrobial elingenazo iikhemikhali, elisekelwe kwi-nanotechnology elinokuthintela iintsholongwane ezingaphezulu nangaphandle komoya kusetyenziswa ii-nanostructures zamanzi ezenziweyo (EWNS). I-EWNS yenziwe kusetyenziswa iinkqubo ezimbini ezihambelanayo, i-electrospray kunye ne-ionization yamanzi (Umzobo 1a). Izifundo zangaphambili zibonise ukuba i-EWNS ineseti eyahlukileyo yeempawu zomzimba nezebhayoloji8,9,10. I-EWNS inomyinge wee-electron ezili-10 kwisakhiwo ngasinye kunye nobukhulu obuphakathi be-nanoscale obuyi-25 nm (Umzobo 1b,c)8,9,10. Ukongeza, i-electron spin resonance (ESR) ibonise ukuba i-EWNS iqulethe inani elikhulu le-reactive oxygen species (ROS), ikakhulu i-hydroxyl (OH•) kunye ne-superoxide (O2-) radicals (Umzobo 1c)8. I-EVNS ihlala emoyeni ixesha elide kwaye inokungqubana neentsholongwane ezixhonywe emoyeni kwaye zibekho phezu komhlaba, zihambisa umthwalo wazo we-ROS kwaye zibangele ukungasebenzi kweentsholongwane (Umzobo 1d). Ezi zifundo zokuqala zikwabonise ukuba i-EWNS inokunxibelelana kwaye ingasebenzi iintsholongwane ezahlukeneyo zegram-negative kunye negram-positive, kuquka i-mycobacteria, kwiindawo eziphezulu nasemoyeni. I-transmission electron microscopy ibonise ukuba ukungasebenzi kubangelwa kukuphazamiseka kwe-membrane yeseli. Ukongeza, izifundo zokuphefumla ngokukhawuleza zibonise ukuba iidosi eziphezulu ze-EWNS azibangeli monakalo okanye ukudumba kwemiphunga 8.
(a) I-Electrospray yenzeka xa kusetyenziswa i-voltage ephezulu phakathi kwetyhubhu ye-capillary equlethe ulwelo kunye ne-counter electrode. (b) Ukusetyenziswa koxinzelelo oluphezulu kubangela iziganeko ezimbini ezahlukeneyo: (i) ukutshiza ngamanzi nge-electrode kunye (ii) ukwenziwa kweentlobo ze-oxygen (ii-ions) ezibambeke kwi-EWNS. (c) Ulwakhiwo olukhethekileyo lwe-EWNS. (d) Ngenxa yendalo yazo ye-nanoscale, i-EWNS iyakwazi ukuhambahamba kakhulu kwaye inokunxibelelana nezifo ezibangelwa zizifo emoyeni.
Amandla eqonga le-EWNS lokulwa neentsholongwane zokubulala iintsholongwane ezifumaneka ekutyeni phezu kokutya okutsha nawo abonakalisiwe kutshanje. Kukwabonakalisiwe ukuba itshaja yomphezulu ye-EWNS xa idibene nentsimi yombane ingasetyenziselwa ukufezekisa ukuhanjiswa okujoliswe kuko. Ngaphezu koko, iziphumo zokuqala zeetamatisi eziphilayo emva kokuvezwa kwi-EWNS yemizuzu engama-90 malunga ne-50,000 #/cm3 bezikhuthaza, kwaye iintsholongwane ezahlukeneyo ezifumaneka ekutyeni ezifana ne-E. coli kunye ne-Listeria 11 zibonile. Ukongeza, uvavanyo lokuqala lwe-organoleptic alubonisanga ziphumo zemvakalelo xa kuthelekiswa neetamatisi zokulawula. Nangona ezi ziphumo zokuqala zokungavuseleli zikhuthaza ukusetyenziswa kokhuseleko lokutya nokuba kukwiidosi ze-EWNS eziphantsi kakhulu ze-50,000#/cc. jonga, kucacile ukuba amandla aphezulu okungavuseleli aya kuba luncedo ngakumbi ekunciphiseni umngcipheko wosulelo kunye nokonakala.
Apha, siza kugxininisa uphando lwethu kuphuhliso lweqonga lokuvelisa i-EWNS ukuze sikwazi ukulungisa kakuhle iiparameter zokwenziwa kunye nokwenza ngcono iipropati ze-physicochemical ze-EWNS ukuphucula amandla azo okulwa neentsholongwane. Ngokukodwa, ukwenza ngcono kugxile ekwandiseni umbane wazo womphezulu (ukuphucula ukuhanjiswa okujoliswe kuko) kunye nomxholo we-ROS (ukuphucula ukusebenza kakuhle kokungasebenzi). Chaza iipropati ze-physico-chemical ezilungiselelweyo (ubukhulu, umbane kunye nomxholo we-ROS) usebenzisa iindlela zanamhlanje zohlalutyo kwaye usebenzise iintsholongwane zokutya eziqhelekileyo ezifana ne-E.
I-EVNS yenziwe ngokutshiza nge-electrospray ngaxeshanye kunye ne-ionization yamanzi acocekileyo aphezulu (18 MΩ cm–1). I-nebulizer yombane 12 isetyenziselwa i-atomization yezinto ezimanzi kunye nokuhlanganiswa kwe-polymer kunye nee-ceramic particles 13 kunye neefayibha 14 zobukhulu obulawulwayo.
Njengoko kuchaziwe kwiimpapasho zangaphambili 8, 9, 10, 11, kuvavanyo oluqhelekileyo, kusetyenziswe i-voltage ephezulu phakathi kwe-capillary yesinyithi kunye ne-counter electrode esekwe phantsi. Ngexesha lale nkqubo, kwenzeka izinto ezimbini ezahlukeneyo: i) i-electrospray kunye nee-ii) i-ionization yamanzi. Intsimi yombane enamandla phakathi kwee-electrodes ezimbini ibangela ukuba kubekho iitshaja ezimbi phezu kwamanzi adibeneyo, nto leyo ebangela ukwakheka kwee-Taylor cones. Ngenxa yoko, kwenziwa amaconsi amanzi atshajiweyo kakhulu, aqhubeka nokuqhekeka abe ngamasuntswana amancinci, njengakwithiyori kaRayleigh16. Kwangaxeshanye, amasimi ombane anamandla abangela ukuba ezinye iimolekyuli zamanzi zahlukane kwaye zisuse ii-electron (ionize), nto leyo ekhokelela ekwakhiweni kwenani elikhulu leentlobo ze-oxygen ezisebenzayo (ROS)17. I-ROS18 eveliswe ngaxeshanye yafakwa kwi-EWNS (Umzobo 1c).
Kumfanekiso 2a ubonisa inkqubo yokuvelisa i-EWNS eyaphuhliswayo neyasetyenziswa kwi-EWNS synthesis kolu phononongo. Amanzi acocekileyo agcinwe kwibhotile evaliweyo afakwa ngetyhubhu yeTeflon (ububanzi bangaphakathi obuyi-2 mm) kwinaliti yentsimbi engagqwaliyo engama-30G (i-capillary yentsimbi). Ukuhamba kwamanzi kulawulwa luxinzelelo lomoya ngaphakathi kwibhotile, njengoko kubonisiwe kuMfanekiso 2b. Inaliti ifakwe kwi-console yeTeflon kwaye ingalungiswa ngesandla ukuya kumgama othile ukusuka kwi-electrode yekhawuntara. I-electrode yekhawuntara yidiski ye-aluminium epholisiweyo enomngxuma embindini wesampuli. Ngaphantsi kwe-electrode yekhawuntara kukho i-funnel yesampuli ye-aluminium, eqhagamshelwe kwenye indawo yokuseta uvavanyo nge-port yesampuli (Umfanekiso 2b). Ukuthintela ukwakheka kwetshaja enokuphazamisa ukusebenza kwesampuli, zonke izinto zesampuli zisekelwe ngombane.
(a) Inkqubo Yokuvelisa Isakhiwo Samanzi Esinobunjineli (i-EWNS). (b) Icandelo elinqamlezileyo lesampulu kunye ne-electrospray, ebonisa iiparameter ezibaluleke kakhulu. (c) Ukuseta kovavanyo lokungasebenzi kweebhaktheriya.
Inkqubo yokuvelisa i-EWNS echazwe apha ngasentla inako ukutshintsha iiparameter zokusebenza ezibalulekileyo ukuze kube lula ukulungisa iipropati ze-EWNS. Lungisa i-voltage esetyenzisiweyo (V), umgama phakathi kwenaliti kunye ne-counter electrode (L), kunye nokuhamba kwamanzi (φ) kwi-capillary ukuze kulungiswe iimpawu ze-EWNS. Uphawu olusetyenziselwa ukumela indibaniselwano ezahlukeneyo: [V (kV), L (cm)]. Lungisa ukuhamba kwamanzi ukuze ufumane ikhowuni yeTaylor ezinzileyo yeseti ethile [V, L]. Ngeenjongo zolu phononongo, ububanzi bomngxuma we-counter electrode (D) bugcinwe kwi-0.5 intshi (1.29 cm).
Ngenxa yejometri elinganiselweyo kunye nokungalingani, amandla entsimi yombane awanakubalwa ngokwemigaqo yokuqala. Endaweni yoko, isoftware yeQuickField™ (Svendborg, Denmark)19 yasetyenziswa ukubala intsimi yombane. Intsimi yombane ayifani, ngoko ke ixabiso lentsimi yombane encotsheni ye-capillary lasetyenziswa njengexabiso lesalathiso kwiindlela ezahlukeneyo zokumisela.
Ngexesha lophando, kuhlolwe iindibaniselwano ezininzi ze-voltage kunye nomgama phakathi kwenaliti kunye ne-counter electrode ngokwemigaqo yokwakheka kwe-Taylor cone, uzinzo lwe-Taylor cone, uzinzo lwemveliso ye-EWNS, kunye nokuphindaphinda. Iindibaniselwano ezahlukeneyo ziboniswe kwiTheyibhile eyoNgezelelweyo S1.
Imveliso yenkqubo yokuvelisa i-EWNS iqhagamshelwe ngqo kwi-Scanning Mobility Particle Size Analyzer (SMPS, Model 3936, TSI, Shoreview, MN) yokulinganisa uxinano lwenani lee-particle, kunye ne-Aerosol Faraday Electrometer (TSI, Model 3068B, Shoreview, MN). ) ye-aerosol currents ilinganiswe njengoko kuchaziwe kwimpapasho yethu yangaphambili. Zombini i-SMPS kunye ne-aerosol electrometer zithathwe iisampulu kwisantya sokuhamba se-0.5 L/min (uxinano lwesampulu iyonke yi-1 L/min). Uxinano lwenani lee-particles kunye nokuhamba kwe-aerosol kulinganiswe imizuzwana eyi-120. Umlinganiselo uphindaphindwa amaxesha angama-30. Ngokusekelwe kumlinganiselo wangoku, umrhumo we-aerosol iyonke uyabalwa kwaye umrhumo we-EWNS oqhelekileyo uqikelelwa kwinani elipheleleyo lee-particles ze-EWNS ezikhethiweyo. Ixabiso eliqhelekileyo le-EWNS linokubalwa kusetyenziswa i-Equation (1):
apho i-IEl ingumbane olinganisiweyo, i-NSMPS luxinzelelo lwedijithali olulinganiswe nge-SMPS, kwaye i-φEl yisantya sokuhamba kwe-electrometer nganye.
Ngenxa yokuba ukufuma okuqhelekileyo (RH) kuchaphazela intlawulo yomphezulu, ubushushu kunye (RH) zigcinwe zingaguquki ngexesha lovavanyo kwi-21°C kunye ne-45%, ngokulandelelana.
I-Atomic force microscopy (AFM), i-Asylum MFP-3D (Asylum Research, Santa Barbara, CA) kunye ne-AC260T probe (Olympus, Tokyo, Japan) zisetyenzisiwe ukulinganisa ubungakanani kunye nobomi be-EWNS. I-AFM scanning frequency yayiyi-1 Hz, indawo yokuskena yayiyi-5 μm × 5 μm, kunye nemigca yokuskena engama-256. Yonke imifanekiso ibekwe phantsi kolungelelwaniso lomfanekiso we-1st order kusetyenziswa isoftware ye-Asylum (ububanzi bemaski yi-100 nm, umda yi-100 pm).
I-funnel yovavanyo isusiwe kwaye umphezulu we-mica ubekwe kumgama we-2.0 cm ukusuka kwi-counter electrode ixesha eliphakathi le-120 s ukuze kuthintelwe ukuhlangana kwamasuntswana kunye nokwenziwa kwamaconsi angaqhelekanga kumphezulu we-mica. I-EWNS itshizwe ngqo kumphezulu we-mica esandul’ ukusikwa (Ted Pella, Redding, CA). Umfanekiso womphezulu we-mica emva nje kokuba i-AFM itshize. I-engile yoqhagamshelwano lomphezulu we-mica esandul’ ukusikwa engaguqukiyo isondele kwi-0°, ngoko ke i-EVNS isasazwa kumphezulu we-mica ngendlela yedome. Ububanzi (a) kunye nokuphakama (h) kwamaconsi asasazekayo balinganiswe ngokuthe ngqo kwi-topography ye-AFM kwaye basetyenziselwa ukubala umthamo we-EWNS domed diffusion kusetyenziswa indlela yethu eqinisekisiweyo ngaphambili. Ukuba i-EWNS ekwibhodi inomthamo ofanayo, ububanzi obulinganayo bungabalwa kusetyenziswa i-Equation (2):
Ngokusekelwe kwindlela yethu eyayiphuhlisiwe ngaphambili, i-electron spin resonance (ESR) spin trap yasetyenziswa ukufumanisa ubukho be-radical intermediates ezihlala ixesha elifutshane kwi-EWNS. Ii-aerosols zafakwa kwi-650 μm Midget sparger (Ace Glass, Vineland, NJ) equlethe isisombululo se-235 mM se-DEPMPO(5-(diethoxyphosphoryl)-5-methyl-1-pyrroline-N-oxide) (Oxis International Inc.). ePortland, eOregon). Zonke izilinganiso ze-ESR zenziwe kusetyenziswa i-Bruker EMX spectrometer (Bruker Instruments Inc. Billerica, MA, USA) kunye ne-flat panel cell. Isoftware ye-Acquisit (Bruker Instruments Inc. Billerica, MA, USA) yasetyenziswa ukuqokelela nokuhlalutya idatha. Ukuqinisekiswa kweempawu ze-ROS kwenziwa kuphela kwiseti yeemeko zokusebenza [-6.5 kV, 4.0 cm]. Amanqanaba e-EWNS alinganiswe kusetyenziswa i-SMPS emva kokubala ilahleko ze-EWNS kwi-impactor.
Amanqanaba e-Ozone ajongwe kusetyenziswa i-205 Dual Beam Ozone Monitor™ (2B Technologies, Boulder, Co)8,9,10.
Kuzo zonke iipropati ze-EWNS, ixabiso eliphakathi lisetyenziswa njengexabiso lokulinganisa, kwaye ukuphambuka okusemgangathweni kusetyenziswa njengempazamo yokulinganisa. Uvavanyo lwe-T lwenziwe ukuthelekisa ixabiso leempawu ze-EWNS ezilungisiweyo kunye namaxabiso ahambelanayo e-base EWNS.
Umfanekiso 2c ubonisa inkqubo yokukhupha i-electrostatic precipitation (EPES) eyayiphuhlisiwe ngaphambili neyayichazwa njenge-"pull" enokusetyenziswa ekuhanjisweni kwe-EWNS kumphezulu. I-EPES isebenzisa iitshaja ze-EVNS ezinokukhokelwa ngqo kumphezulu wethagethi phantsi kwempembelelo yentsimi yombane enamandla. Iinkcukacha zenkqubo ye-EPES ziboniswe kwimpapasho yakutshanje kaPyrgiotakis et al. 11. Ngoko ke, i-EPES inegumbi le-PVC eliprintiweyo le-3D elineziphelo ezinciphileyo kwaye liqulathe iipleyiti zesinyithi ezimbini ezilinganayo zentsimbi engagqwaliyo (304 stainless steel, mirror coated) embindini ongama-15.24 cm ukusuka komnye. Iibhodi zaziqhagamshelwe kumthombo wangaphandle we-voltage ephezulu (Bertran 205B-10R, Spellman, Hauppauge, NY), ipleyiti esezantsi yayisoloko iqhagamshelwe kwi-voltage elungileyo, kwaye ipleyiti ephezulu yayisoloko iqhagamshelwe emhlabeni (umhlaba odadayo). Iindonga zegumbi zigqunywe ngefoyile ye-aluminium, eqiniswe ngombane ukuthintela ukulahleka kwamasuntswana. Igumbi linomnyango ongaphambili ovaliweyo ovumela ukuba iindawo zovavanyo zibekwe kwizitendi zeplastiki eziziphakamisa ngaphezu kwepleyiti yesinyithi esezantsi ukuze kuthintelwe ukuphazamiseka kombane ophezulu.
Ukusebenza kakuhle kwe-EWNS kwi-EPES kubalwe ngokweprotokholi eyayiphuhlisiwe ngaphambili echazwe kwi-Supplementary Figure S111.
Njengegumbi lokulawula, igumbi lesibini lokuhamba eliyi-cylindrical ladibaniswa ngochungechunge kwinkqubo ye-EPES, apho kwasetyenziswa isihluzo se-HEPA esiphakathi ukususa i-EWNS. Njengoko kubonisiwe kuMfanekiso 2c, i-aerosol ye-EWNS yaphonswa kwiigumbi ezimbini ezakhelwe ngaphakathi. Isihluzo esiphakathi kwegumbi lokulawula kunye ne-EPES sisusa naziphi na ii-EWNS eziseleyo nto leyo ekhokelela kubushushu obufanayo (T), umswakama ohambelanayo (RH) kunye namanqanaba e-ozone.
Kufunyenwe ukuba iintsholongwane ezibalulekileyo ezifumaneka ekutyeni zingcolisa ukutya okutsha okufana ne-E. coli (ATCC #27325), i-fecal indicator, i-Salmonella enterica (ATCC #53647), i-foodborne pathogen, i-Listeria engenabungozi (ATCC #33090), indawo ye-pathogenic Listeria monocytogenes, ethathwe kwi-ATCC (Manassas, VA) Saccharomyces cerevisiae (ATCC #4098), indawo ye-spoilage yeast, kunye ne-inhibitory engasebenziyo enamandla ngakumbi, i-Mycobacterium paralucky (ATCC #19686).
Thenga iibhokisi zeetumato zediliya ezingacwangciswanga kwimarike yakho yasekuhlaleni uze uzibeke efrijini kwi-4°C de zisetyenziswe (ukuya kuthi ga kwiintsuku ezi-3). Zonke iitumato ezivavanyiweyo zazilingana ngobukhulu, malunga ne-1/2 intshi ububanzi.
Iindlela zokulima, ukugonyelwa, ukuvezwa, kunye nokubalwa kwekoloni zichazwe kwimpapasho yethu yangaphambili kwaye zichazwe kwiDatha eyoNgezelelweyo. Ukusebenza kwe-EWNS kuhlolwe ngokubeka iitamatisi ezigonyelwe kwi-40,000 #/cm3 imizuzu engama-45. Ngamafutshane, iitamatisi ezintathu zisetyenzisiwe ukuvavanya iintsholongwane ezisindileyo ngexesha t = 0 min. Iitamatisi ezintathu zibekwe kwi-EPES kwaye zabekwa kwi-EWNS kwi-40,000 #/cc (iitamatisi ezigonyelwe yi-EWNS) kwaye ezintathu eziseleyo zabekwa kwigumbi lokulawula (iitamatisi zokulawula). Ukulungiswa okongezelelweyo kweetamatisi kumaqela omabini akwenziwanga. Iitamatisi ezigonyelwe yi-EWNS kunye neetamatisi zokulawula zisusiwe emva kwemizuzu engama-45 ukuvavanya isiphumo se-EWNS.
Uvavanyo ngalunye lwenziwe ngokuphindwe kathathu. Uhlalutyo lwedatha lwenziwe ngokwemigaqo echazwe kwiDatha eyoNgezelelweyo.
Iindlela zokungasebenzi zihlolwe ngokuthuthwa kweesampuli ze-EWNS eziveziweyo (imizuzu engama-45 kuxinzelelo lwe-aerosol lwe-EWNS oluyi-40,000 #/cm3) kunye neesampuli ezingafakwanga imitha zebhaktheriya engenabungozi i-E. coli, i-Salmonella enterica kunye ne-Lactobacillus. La masuntswana aqiniswe kwi-2.5% glutaraldehyde, i-1.25% paraformaldehyde kunye ne-0.03% picric acid kwi-0.1 M sodium cacodylate buffer (pH 7.4) iiyure ezi-2 kubushushu begumbi. Emva kokuhlamba, lungisa emva kokulungisa nge-1% osmium tetroxide (OsO4)/1.5% potassium ferrocyanide (KFeCN6) iiyure ezi-2, uhlambe kathathu emanzini uze ufukame kwi-1% uranyl acetate iyure e-1, uze uhlambe kabini emanzini, uze ukhuphe amanzi imizuzu eli-10 kwi-50%, 70%, 90%, 100% alcohol. Emva koko iisampulu zafakwa kwi-propylene oxide kangangeyure e-1 zaza zafakwa umxube we-1:1 we-propylene oxide kunye ne-TAAP Epon (Marivac Canada Inc. St. Laurent, CA). Iisampulu zafakwa kwi-TAAB Epon zaza zapholishwa kwi-60°C kangangeeyure ezingama-48. I-resin ecociweyo ye-granular yasikwa yaza yabonwa yi-TEM kusetyenziswa i-transmission electron microscope eqhelekileyo i-JEOL 1200EX (JEOL, Tokyo, Japan) exhotyiswe ngekhamera ye-AMT 2k CCD (Advanced Microscopy Techniques, Corp., Woburn, Massachusetts, USA).
Zonke iimvavanyo zenziwe kathathu. Kwinqaku ngalinye lexesha, ukuhlamba iintsholongwane kuhlwayelwe kathathu, nto leyo eyabangela ukuba kubekho amanqaku edatha alithoba ngenqaku ngalinye, umyinge walo usetyenziswe njengoxinzelelo lweentsholongwane kuloo microorganism ithile. Ukuphambuka okuqhelekileyo kusetyenziswe njengempazamo yokulinganisa. Onke amanqaku abalwa.
I-logarithm yokwehla koxinzelelo lweebhaktheriya xa kuthelekiswa ne-t = 0 min ibalwe kusetyenziswa le fomyula ilandelayo:
apho i-C0 luxinzelelo lweebhaktheriya kwisampulu yokulawula ngexesha elingu-0 (oko kukuthi emva kokuba umphezulu womile kodwa ngaphambi kokuba ubekwe kwigumbi) kwaye i-Cn luxinzelelo lweebhaktheriya kumphezulu emva kwemizuzu engama-n yokuvezwa.
Ukuze kujongwe ukuwohloka kwendalo kweebhaktheriya ngexesha lokuvezwa kwemizuzu engama-45, ukuncitshiswa kwelog xa kuthelekiswa nolawulo emva kwemizuzu engama-45 nako kubalwe ngolu hlobo lulandelayo:
apho i-Cn luxinzelelo lweebhaktheriya kwisampulu yokulawula ngexesha le-n kwaye i-Cn-Control luxinzelelo lweebhaktheriya zokulawula ngexesha le-n. Idatha iboniswa njengokunciphisa kwelog xa kuthelekiswa nolawulo (akukho kuvezwa kwe-EWNS).
Ngexesha lophando, kuhlolwe iindidi ezahlukeneyo ze-voltage kunye nomgama phakathi kwenaliti kunye ne-counter electrode ngokwendlela yokwakheka kwe-Taylor cone, uzinzo lwe-Taylor cone, uzinzo lwemveliso ye-EWNS, kunye nokuphinda kuvele. Iindidi ezahlukeneyo ziboniswe kwiTheyibhile eyoNgezelelweyo S1. Iimeko ezimbini ezibonisa iipropati ezizinzileyo neziphinda kuvele (i-Taylor cone, i-EWNS generation, kunye nozinzo ngokuhamba kwexesha) zikhethwe ukuze kufundwe ngokubanzi. Kumfanekiso. Umfanekiso 3 ubonisa iziphumo zetshaja, ubungakanani, kunye nomxholo we-ROS kuzo zombini iimeko. Iziphumo zikwashwankathelwe kwiTheyibhile 1. Njengesalathiso, zombini uMfanekiso 3 kunye neTheyibhile 1 ziquka iipropati ze-EWNS8, 9, 10, 11 ezingazange zilungiswe ngaphambili (baseline-EWNS). Ubalo lokubaluleka kwezibalo olusebenzisa uvavanyo lwe-t olunemisila emibini lupapashwe kwakhona kwiTheyibhile eyoNgezelelweyo S2. Ukongeza, idatha eyongezelelweyo ibandakanya izifundo zesiphumo se-counter electrode sampling hole diameter (D) kunye nomgama phakathi kwe-ground electrode kunye ne-tip (L) (Iimpawu eziyoNgezelelweyo S2 kunye ne-S3).
(ac) Ukusasazwa kobungakanani kulinganiswa yi-AFM. (df) Uphawu lwetshaja yomphezulu. (g) Ukuchazwa kwe-ROS ye-EPR.
Kubalulekile kwakhona ukuqaphela ukuba kuzo zonke ezi meko zingasentla, umsinga we-ionization olinganisiweyo wawuphakathi kwe-2 kunye ne-6 μA kunye ne-voltage ephakathi kwe--3.8 kunye ne--6.5 kV, nto leyo eyabangela ukusetyenziswa kwamandla okungaphantsi kwe-50 mW kule module yoqhagamshelwano yesizukulwana se-EWNS enye. Nangona i-EWNS yenziwe phantsi koxinzelelo oluphezulu, amanqanaba e-ozone ayephantsi kakhulu, engadluli kwi-60 ppb.
Umfanekiso ongezelelweyo S4 ubonisa amasimi ombane alinganisiweyo kwi-[-6.5 kV, 4.0 cm] kunye ne-[-3.8 kV, 0.5 cm], ngokulandelelana. Kwi-[-6.5 kV, 4.0 cm] kunye ne-[-3.8 kV, 0.5 cm], izibalo zamasimi ziyi-2 × 105 V/m kunye ne-4.7 × 105 V/m, ngokulandelelana. Oku kulindeleke, kuba kwimeko yesibini umlinganiselo womgama we-voltage uphezulu kakhulu.
Kumfanekiso 3a, b ubonisa ububanzi be-EWNS obulinganiswe nge-AFM8. Umyinge oqikelelweyo we-EWNS ububanzi yayiyi-27 nm kunye ne-19 nm kwi-[-6.5 kV, 4.0 cm] kunye ne-[-3.8 kV, 0.5 cm], ngokwahlukeneyo. Kwiimeko ze-[-6.5 kV, 4.0 cm] kunye ne-[-3.8 kV, 0.5 cm], ukuphambuka okusemgangathweni kwejometri kokusasazwa yi-1.41 kunye ne-1.45, ngokwahlukeneyo, okubonisa ukusasazwa kobukhulu obuncinci. Zombini ubungakanani obuphakathi kunye nokuphambuka okusemgangathweni kwejometri zisondele kakhulu kwi-baseline EWNS, kwi-25 nm kunye ne-1.41, ngokwahlukeneyo. Kumfanekiso 3c ubonisa ukusasazwa kobungakanani be-baseline EWNS elinganiswe kusetyenziswa indlela efanayo phantsi kweemeko ezifanayo.
Kumfanekiso 3d,e ubonisa iziphumo zokuchazwa kwetshaja. Idatha yimilinganiselo ephakathi yeemilinganiselo ezingama-30 ngaxeshanye zoxinzelelo (#/cm3) kunye nombane (I). Uhlalutyo lubonisa ukuba itshaja ephakathi kwi-EWNS yi-22 ± 6 e- kunye ne-44 ± 6 e- kwi-[-6.5 kV, 4.0 cm] kunye ne-[-3.8 kV, 0.5 cm], ngokwahlukeneyo. Zineentlawulo eziphezulu kakhulu zomphezulu xa kuthelekiswa ne-baseline EWNS (10 ± 2 e-), ezinkulu kabini kune-[-6.5 kV, 4.0 cm] kwaye zinkulu kane kune-[-3 .8 kV, 0.5 cm]. Umfanekiso 3f ubonisa idatha yetshaja. ye-Baseline-EWNS.
Ukusuka kwiimephu zoxinaniso lwenombolo ye-EWNS (Imifanekiso eyongezelelweyo S5 kunye ne-S6), kunokubonwa ukuba imeko ye-[-6.5 kV, 4.0 cm] inamasuntswana amaninzi kakhulu kunemeko ye-[-3.8 kV, 0.5 cm]. Kubalulekile nokuqaphela ukuba uxinzelelo lwenombolo ye-EWNS lujongwe ukuya kuthi ga kwiiyure ezi-4 (Imifanekiso eyongezelelweyo S5 kunye ne-S6), apho uzinzo lwesizukulwana se-EWNS lubonise amanqanaba afanayo oxinaniso lwenombolo yamasuntswana kuzo zombini iimeko.
Kumfanekiso 3g ubonisa i-EPR spectrum emva kokukhupha ulawulo lwe-EWNS olulungisiweyo (imvelaphi) kwi-[-6.5 kV, 4.0 cm]. Ii-ROS spectra nazo zithelekiswe nomzekelo we-Baseline-EWNS kumsebenzi opapashwe ngaphambili. Inani le-EWNS elisabela kwiitraphu ze-spin libalwe libe yi-7.5 × 104 EWNS/s, elifana ne-Baseline-EWNS8 epapashwe ngaphambili. Ii-EPR spectra zibonise ngokucacileyo ukubakho kweentlobo ezimbini ze-ROS, apho i-O2- iluhlobo oluphambili kwaye i-OH• incinci kakhulu. Ukongeza, uthelekiso oluthe ngqo lwe-peak intensities lubonise ukuba i-EWNS elungisiweyo yayinomxholo we-ROS ophezulu kakhulu xa kuthelekiswa ne-baseline EWNS.
Kumfanekiso 4 ubonisa ukusebenza kakuhle kwe-EWNS kwi-EPES. Idatha ikwashwankathelwe kwiTheyibhile I kwaye ithelekiswa nedatha yokuqala ye-EWNS. Kuzo zombini iimeko ze-EUNS, ukufakwa kusondele kwi-100% nokuba kukwi-voltage ephantsi ye-3.0 kV. Ngokwesiqhelo, i-3.0 kV yanele ukufakwa kwe-100%, nokuba utshintsho lwetshaja yomphezulu lunjani. Phantsi kweemeko ezifanayo, ukusebenza kakuhle kwe-Baseline-EWNS yayiyi-56% kuphela ngenxa yetshaja yabo ephantsi (umyinge wee-electron ezili-10 kwi-EWNS nganye).
Kumfanekiso 5 nakwitheyibhile 2 sishwankathela ixabiso lokungasebenzi kweentsholongwane ezifakwe kwi-incubator phezu kweetamatisi emva kokuvezwa kwi-40,000 #/cm3 EWNS imizuzu engama-45 kwimo efanelekileyo [-6.5 kV, 4.0 cm]. I-E. coli efakwe kwi-incubator kunye ne-Lactobacillus innocuous zibonise ukwehla okukhulu kwee-logs ezingama-3.8 ngexesha lokuvezwa kwimizuzu engama-45. Phantsi kweemeko ezifanayo, i-S. enterica inciphe nge-2.2-log, ngelixa i-S. cerevisiae kunye ne-M. parafortutum zinciphe nge-1.0-log.
Ii-electron micrographs (Umfanekiso 6) zibonisa utshintsho olubangelwa yi-EWNS kwiiseli ze-Escherichia coli ezingenabungozi, iStreptococcus, kunye neLactobacillus ezikhokelela ekungasebenzini kwazo. Iibhaktheriya zokulawula zazinee-membrane zeseli ezipheleleyo, ngelixa iibhaktheriya eziveziweyo zonakalisile ii-membrane zangaphandle.
Umfanekiso we-electron microscopic wolawulo kunye neebhaktheriya eziveziweyo ubonise umonakalo kwi-membrane.
Idatha kwiipropati ze-physicochemical ze-EWNS ezilungisiweyo ngokudibeneyo ibonisa ukuba iipropati (itshaja yomphezulu kunye nomxholo we-ROS) ze-EWNS ziphuculwe kakhulu xa kuthelekiswa nedatha yesiseko ye-EWNS epapashwe ngaphambili8,9,10,11. Kwelinye icala, ubungakanani bazo buhlale kuluhlu lwe-nanometer, bufana kakhulu neziphumo ezibikwe ngaphambili, zivumela ukuba zihlale emoyeni ixesha elide. Ukwanda kwe-polydispersity ebonweyo inokuchazwa lutshintsho lwetshaja yomphezulu olumisela ubungakanani be-EWNS, ukungacwangciswanga kwesiphumo seRayleigh, kunye nokubumbana okunokwenzeka. Nangona kunjalo, njengoko kuchaziwe nguNielsen et al. 22, itshaja yomphezulu ephezulu inciphisa ukufuma ngokunyusa ngempumelelo amandla omphezulu/uxinzelelo lokuwa kwamanzi. Kwimpapasho yethu yangaphambili8 le ngcamango yaqinisekiswa ngovavanyo kwi-microdroplets 22 kunye ne-EWNS. Ukulahleka kwetshaja ngexesha elongezelelweyo kunokuchaphazela ubungakanani kwaye kunegalelo ekusasazweni kobungakanani obubonwayo.
Ukongeza, itshaja ngesakhiwo ngasinye imalunga ne-22-44 e-, kuxhomekeke kwimeko, ephezulu kakhulu xa ithelekiswa ne-basic EWNS, enetshaja ephakathi ye-10 ± 2 electrons ngesakhiwo ngasinye. Nangona kunjalo, kufuneka kuqatshelwe ukuba le yitshaja ephakathi ye-EWNS. Seto et al. Kuye kwaboniswa ukuba itshaja ayifani kwaye ilandela usasazo oluqhelekileyo lwe-log21. Xa kuthelekiswa nomsebenzi wethu wangaphambili, ukuphinda kabini itshaja yomphezulu kuphinda kabini ukusebenza kakuhle kwe-depositi kwinkqubo ye-EPES ukuya phantse kwi-100%11.