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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 zityebile kwiintlobo ze-oxygen (ROS) ezinokusebenzisana kwaye zivale inani leentsholongwane, kuquka nezifo ezifumaneka ekutyeni. Apha kuboniswa ukuba iipropati zazo ngexesha lokwenziwa zinokulungiswa kwaye ziphuculwe ukuze ziphucule 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) kwenziwe kusetyenziswa iindlela zanamhlanje zohlalutyo. Ukongeza, iintsholongwane zokutya ezifana ne-Escherichia coli, i-Salmonella enterica, i-Listeria innocua, i-Mycobacterium para fortitum, kunye ne-Saccharomyces cerevisiae zifakwe kwi-organic grape tomatoes ukuvavanya amandla azo okungasebenzi kwe-microbial. Iziphumo ezivezwe apha zibonisa ukuba iipropati ze-EWNS zinokulungiswa ngexesha lokwenziwa, nto leyo ekhokelela ekwandeni okukhulu ekusebenzeni kokungasebenzi. Ngokukodwa, intlawulo yomphezulu yonyuke ngesiqingatha sesine, kwaye umxholo weROS wonyuka. Izinga lokususwa kweentsholongwane lalixhomekeke kwiintsholongwane kwaye laliqala kwi-1.0 ukuya kwi-3.8 log emva kwemizuzu engama-45 yokuvezwa kwidosi ye-aerosol engama-40,000 #/cm3 EWNS.
Ungcoliseko lweentsholongwane zezona zinto zibangela izifo ezibangelwa kukutya okubangelwa kukutya okubangelwa kukutya okubangelwa zizifo ezibangelwa ziintsholongwane okanye iityhefu zazo. Izifo ezibangelwa kukutya zibangela izifo ezimalunga nezigidi ezingama-76, ukulaliswa esibhedlele ezingama-325,000, kunye nokufa kwabantu abangama-5,000 minyaka le eMelika kuphela1. Ukongeza, iSebe lezoLimo lase-United States (i-USDA) liqikelela ukuba ukusetyenziswa kakhulu kwemveliso emitsha kubangele ama-48 ekhulwini azo zonke izifo ezibangelwa kukutya ezixeliweyo eMelika2. Ixabiso lokugula nokufa ngenxa yezifo ezibangelwa kukutya eMelika liphezulu kakhulu, liqikelelwa yiZiko loLawulo lweZifo kunye nokuThintela (i-CDC) ngaphezulu kwe-US$15.6 yeebhiliyoni ngonyaka3.
Okwangoku, ukungenelela kweekhemikhali4, imitha5 kunye ne-thermal6 antimicrobial ukuqinisekisa ukhuseleko lokutya kwenziwa ikakhulu kwiindawo zokulawula ezibalulekileyo (ii-CCP) kwikhonkco lemveliso (ngesiqhelo emva kokuvuna kunye/okanye ngexesha lokupakisha) endaweni yokusetyenziswa rhoqo ngendlela yokuba imveliso entsha ingcoliswe ziintsholongwane ezahlukeneyo 7. Ukungenelela kwee-antimicrobial kuyadingeka ukulawula ngcono izifo ezibangelwa kukutya kunye nokonakala kokutya kwaye kunokubakho ukusetyenziswa kuyo yonke i-farm-to-table continuum. Impembelelo encinci kunye neendleko ezincinci.
Kutshanje kuye kwaphuhliswa iqonga le-nanotechnology elingenayo i-antimicrobial elisekelwe kwi-nanotechnology ukuze lingasebenzi iintsholongwane kwiindawo eziphezulu nasemoyeni kusetyenziswa ii-nanostructures zamanzi ezenziweyo (EWNS). Ukwenziwa kwe-EVNS, kusetyenziswe iinkqubo ezimbini ezifanayo: i-electrospray kunye ne-ionization yamanzi (Umzobo 1a). I-EWNS ngaphambili iboniswe ukuba ineseti eyahlukileyo yeempawu zomzimba nezebhayoloji8,9,10. I-EWNS inomyinge wee-electron ezili-10 kwisakhiwo ngasinye kunye nobukhulu obuphakathi be-nanometer 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-EWNS yahlala emoyeni ixesha elide kwaye inokungqubana nee-microbes ezixhonywe emoyeni kwaye zibekho kwiindawo eziphezulu, zihambisa umthwalo wazo we-ROS kwaye zibangele ukungasebenzi kwee-microbial (Umzobo 1d). Ezi zifundo zangaphambili zikwabonise ukuba i-EWNS inokunxibelelana kwaye ingasebenzi iintsholongwane ezahlukeneyo ze-gram-negative kunye ne-gram-positive ezibalulekileyo kwimpilo yoluntu, kubandakanya i-mycobacteria, kwiindawo eziphezulu nasemoyeni8,9. 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 kwemiphunga8.
(a) I-Electrospray yenzeka xa kusetyenziswa i-voltage ephezulu phakathi kwe-capillary equlethe ulwelo kunye ne-counter electrode. (b) Ukusetyenziswa kwe-voltage ephezulu kubangela iziganeko ezimbini ezahlukeneyo: (i) ukutshiza ngamanzi nge-electrode kunye (ii) ukuveliswa kweentlobo ze-oxygen (ii-ions) ezibambeke kwi-EWNS. (c) Ulwakhiwo olukhethekileyo lwe-EWNS. (d) I-EWNS ihamba kakhulu ngenxa yendalo yayo ye-nanoscale kwaye inokunxibelelana ne-pathogens emoyeni.
Amandla eqonga le-EWNS lokulwa neentsholongwane zokubulala iintsholongwane ezifumaneka ekutyeni phezu kokutya okutsha nawo abonakalisiwe kutshanje. Kwakhona kubonisiwe ukuba umbane womphezulu we-EWNS ungasetyenziswa kunye nentsimi yombane ukuze kuhanjiswe ekujoliswe kuyo. Okubaluleke ngakumbi, isiphumo sokuqala esithembisayo sokunciphisa malunga ne-1.4 log yomsebenzi wetamatato eziphilayo ngokuchasene neentsholongwane ezahlukeneyo zokutya ezifana ne-E. coli kunye neListeria sabonwa kwimizuzu engama-90 emva kokuvezwa kwi-EWNS kuxinzelelo olumalunga ne-50,000#/cm311. Ukongeza, uvavanyo lokuqala lwe-organoleptic alubonisanga mpembelelo ye-organoleptic xa kuthelekiswa netamatato yokulawula. Nangona ezi ziphumo zokuqala zokungavuseleli zithembisa ukhuseleko lokutya nokuba kwiidosi ze-EWNS eziphantsi kakhulu ze-50,000#/cc. jonga, kucacile ukuba amandla aphezulu okungavuseleli aya kuba luncedo ngakumbi ekunciphiseni ngakumbi umngcipheko wosulelo kunye nokonakala.
Apha, siza kugxininisa uphando lwethu kuphuhliso lweqonga lokuvelisa i-EWNS ukuze kulungiswe iiparamitha zokwenziwa kunye nokuphucula iipropati ze-physicochemical ze-EWNS ukuphucula amandla azo okulwa neentsholongwane. Ngokukodwa, ukulungiswa kugxile ekwandiseni umbane wabo womphezulu (ukuphucula ukuhanjiswa okujoliswe kuko) kunye nomxholo we-ROS (ukuphucula ukusebenza kakuhle kokungasebenzi). Ukuchazwa kweepropati ze-physico-chemical ezilungiselelweyo (ubungakanani, umbane kunye nomxholo we-ROS) kusetyenziswa iindlela zanamhlanje zohlalutyo kunye nokusebenzisa iintsholongwane zokutya eziqhelekileyo ezifana ne-E. coli, i-S. enterica, i-L. innocua, i-S. cerevisiae kunye ne-M. parafortuitum.
I-EVNS yenziwe ngokutshiza nge-electro ngaxeshanye kunye nokufaka amanzi acocekileyo aphezulu kwi-ionization (18 MΩ cm–1). I-atomizer yombane 12 idla ngokusetyenziselwa ukwenza i-atomize ulwelo kunye ne-polymer yokwenziwa kunye namaqhekeza e-ceramic 13 kunye neefayibha 14 zobukhulu obulawulwayo.
Njengoko kuchaziwe kwiimpapasho zangaphambili 8, 9, 10, 11, kuvavanyo oluqhelekileyo, kusetyenziswa i-voltage ephezulu phakathi kwe-capillary yesinyithi kunye ne-counter electrode esekwe phantsi. Ngexesha lale nkqubo, kwenzeka izinto ezimbini ezahlukeneyo: 1) i-electrospray kunye ne-2) 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, ngokwethiyori kaRayleigh16. Kwangaxeshanye, intsimi yombane enamandla ibangela ukuba ezinye zeemolekyuli zamanzi zahlukane kwaye zisuse ii-electron (ionization), ngaloo ndlela zivelise inani elikhulu leentlobo ze-oxygen ezisebenzayo (ROS)17. Iipakethi zeROS18 ezenziwe ngaxeshanye zifakwe kwi-EWNS (Umzobo 1c).
Kumfanekiso 2a ubonisa inkqubo yokuvelisa i-EWNS eyenziwe yaza yasetyenziswa 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). Njengoko kubonisiwe kuMfanekiso 2b, ukuhamba kwamanzi kulawulwa luxinzelelo lomoya ngaphakathi kwibhotile. Inaliti inamathele kwi-console yeTeflon enokulungiswa ngesandla ukuya kumgama othile ukusuka kwi-electrode yekhawuntara. I-electrode yekhawuntara yidiski ye-aluminium epholisiweyo enomngxuma phakathi ukuze kuthathwe isampuli. Ngaphantsi kwe-electrode yekhawuntara kukho i-funnel yesampulu ye-aluminium, eqhagamshelwe kwenye indawo yokuseta uvavanyo nge-port yesampulu (Umfanekiso 2b). Zonke izinto zesampulu zisekelwe ngombane ukuze kuthintelwe ukwakheka kwetshaja okunokonakalisa isampuli yamasuntswana.
(a) Inkqubo Yokuvelisa Isakhiwo Samanzi Esinobunjineli (i-EWNS). (b) Icandelo elinqamlezileyo leyunithi yesampulu 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 kakuhle iipropati ze-EWNS. Lungisa i-voltage esetyenzisiweyo (V), umgama phakathi kwenaliti kunye ne-counter electrode (L), kunye nokuhamba kwamanzi (φ) kwi-capillary ukuze kulungiswe kakuhle iimpawu ze-EWNS. Iimpawu [V (kV), L (cm)] zisetyenziselwa ukubonisa indibaniselwano ezahlukeneyo. Lungisa ukuhamba kwamanzi ukuze ufumane ikhowuni yeTaylor ezinzileyo yeseti ethile [V, L]. Ngeenjongo zolu phononongo, i-aperture ye-counter electrode (D) ibekwe 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 Sizer (SMPS, model 3936, TSI, Shoreview, Minnesota) ukulinganisa uxinaniso lwenani lamasuntswana kwaye yasetyenziswa ne-Faraday aerosol electrometer (TSI, model 3068B, Shoreview, USA). MN) ukulinganisa ukuhamba kwe-aerosol, njengoko kuchaziwe kwimpapasho yethu yangaphambili9. Zombini i-SMPS kunye ne-aerosol electrometer zisampulwe ngesantya sokuhamba se-0.5 L/min (uxinaniso lwesampuli iyonke yi-1 L/min). Uxinaniso lwamasuntswana kunye noxinaniso lwe-aerosol zilinganiswe imizuzwana eli-120. Phinda umlinganiselo amaxesha angama-30. Intlawulo iyonke ye-aerosol ibalwa ngokwemilinganiselo yangoku, kwaye intlawulo ye-EWNS ephakathi iqikelelwa kwinani lilonke lamasuntswana e-EWNS asampulwe. Ixabiso eliphakathi le-EWNS linokubalwa kusetyenziswa i-Equation (1):
apho i-IEl ingumbane olinganisiweyo, i-NSMPS luxinzelelo lwamanani olulinganiswa nge-SMPS, kwaye i-φEl lizinga lokuhamba kwamanzi ukuya kwi-electrometer.
Ngenxa yokuba ukufuma okuqhelekileyo (RH) kuchaphazela ukutshaja komphezulu, ubushushu kunye (RH) zigcinwe zingaguquki kwi-21°C kunye ne-45%, ngokulandelelana, ngexesha lovavanyo.
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. Isantya se-AFM scan yi-1 Hz kwaye indawo ye-scan yi-5 µm×5 µm enemigca ye-scan engama-256. Yonke imifanekiso ibekwe phantsi kolungelelwaniso lomfanekiso wokuqala kusetyenziswa isoftware ye-Asylum (imaski enoluhlu lwe-100 nm kunye nomda we-100 pm).
Susa i-sampling funnel uze ubeke umphezulu we-mica 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 ifakwe ngqo kwiindawo ezisandula ukusika ze-mica (Ted Pella, Redding, CA). Emva nje kokutshiza, umphezulu we-mica wabonwa kusetyenziswa i-AFM. I-engile yokunxibelelana komphezulu we-mica engakagqitywa isondele kwi-0°, ngoko ke i-EWNS isasazeka phezu komphezulu we-mica kwimo ye-domed20. Ububanzi (a) kunye nokuphakama (h) kwamaconsi asasazekayo balinganiswe ngokuthe ngqo kwi-topography ye-AFM kwaye basetyenziselwa ukubala umthamo we-domed diffusion EWNS kusetyenziswa indlela yethu eqinisekisiweyo ngaphambili8. Ukuba i-EVNS ekwibhodi inomthamo ofanayo, ububanzi obufanayo bungabalwa kwi-equation (2):
Ngokuhambelana nendlela yethu eyayiphuhlisiwe ngaphambili, kwasetyenziswa i-electron spin resonance (ESR) spin trap ukufumanisa ubukho be-radical intermediates ezihlala ixesha elifutshane kwi-EWNS. Ii-aerosols zadlula kwisisombululo esine-235 mM DEPMPO (5-(diethoxyphosphoryl)-5-methyl-1-pyrroline-N-oxide) (Oxis International Inc., ePortland, eOregon). Zonke izilinganiso ze-EPR zenziwe kusetyenziswa i-Bruker EMX spectrometer (Bruker Instruments Inc. Billerica, MA, USA) kunye ne-flat cell arrays. Isoftware ye-Acquisit (Bruker Instruments Inc. Billerica, MA, USA) yasetyenziswa ukuqokelela nokuhlalutya idatha. Ukuchazwa kwe-ROS kwenziwa kuphela kwiseti yeemeko zokusebenza [-6.5 kV, 4.0 cm]. Amanqanaba e-EWNS alinganiswe kusetyenziswa i-SMPS emva kokuqwalasela ukulahleka kwe-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 lokulinganisa liyi-mean yemilinganiselo, kwaye impazamo yokulinganisa yi-standard deviation. Kwenziwe uvavanyo lwe-t ukuze kuthelekiswe ixabiso le-attribute ye-EWNS elungisiweyo kunye nexabiso elihambelanayo le-base EWNS.
Umfanekiso 2c ubonisa iNkqubo yokuDlulela kwi-Electrostatic Precipitation Pass Through System (EPES) eyayiphuhlisiwe ngaphambili neyayinokuchazwa, enokusetyenziswa ukujolisa kwi-EWNS11 kwiindawo eziphezulu. I-EPES isebenzisa itshaja ye-EWNS kunye nentsimi yombane enamandla "ukukhomba" ngqo kumphezulu wethagethi. Iinkcukacha zenkqubo ye-EPES ziboniswe kwimpapasho yakutshanje kaPyrgiotakis et al.11. Ngoko ke, i-EPES inegumbi le-PVC eliprintiweyo le-3D elineziphelo ezinciphileyo eziqulathe iipleyiti zesinyithi ezimbini ezilinganayo zentsimbi engagqwaliyo (intsimbi engagqwaliyo engama-304, epolishiweyo yesipili) embindini we-15.24 cm ukusuka komnye. Iibhodi zaziqhagamshelwe kumthombo wangaphandle we-voltage ephezulu (Bertran 205B-10R, Spellman, Hauppauge, NY), ibhodi esezantsi yayisoloko ilungile kwaye ibhodi ephezulu yayisoloko iphantsi (idada). Iindonga zegumbi zigqunywe ngefoyile ye-aluminium, efakwe umbane ukuthintela ukulahleka kwamasuntswana. Igumbi linomnyango wokulayisha ovaliweyo ovumela ukuba iindawo zovavanyo zibekwe kwiirakhi zeplastiki, ziphakamise kwipleyiti yesinyithi esezantsi ukuthintela ukuphazamiseka kwe-voltage ephezulu.
Ukusebenza kakuhle kwe-EWNS kwi-EPES kubalwe ngokweprotokholi eyayiphuhlisiwe ngaphambili echazwe kwi-Supplementary Figure S111.
Njengegumbi lokulawula, ukuhamba kwesibini kwigumbi elisilinda kuqhagamshelwe ngokulandelelana nenkqubo ye-EPES kusetyenziswa isihluzi se-HEPA esiphakathi ukususa i-EWNS. Njengoko kubonisiwe kumzobo 2c, i-aerosol ye-EWNS ipompelwe macala amabini aqhagamshelwe ngokulandelelana. Isihluzi esiphakathi kwegumbi lokulawula kunye ne-EPES sisusa nayiphi na i-EWNS eseleyo nto leyo ekhokelela kubushushu obufanayo (T), umswakama ohambelanayo (RH) kunye namanqanaba e-ozone.
Kufunyenwe ukuba iintsholongwane ezibalulekileyo ezifumaneka ekutyeni zingcolisa imveliso emitsha efana ne-Escherichia coli (ATCC #27325), isalathisi sendle, i-Salmonella enterica (ATCC #53647), intsholongwane efumaneka ekutyeni, i-Listeria innocua (ATCC #33090), enye indlela ye-Listeria monocytogenes. , i-Saccharomyces cerevisiae (ATCC #4098) njengendlela ye-spoilage yeast, kunye ne-Mycobacterium parafortuitous (ATCC #19686) njengeentsholongwane eziphilayo ezimelana ngakumbi zithengwe kwi-ATCC (Manassas, eVirginia).
Thenga iibhokisi zeetumato zediliya ezingavuthwanga kwimarike yakho yasekuhlaleni uze uzibeke efrijini kwi-4°C de zisetyenziswe (ukuya kuthi ga kwiintsuku ezi-3). Khetha iitumato ukuze uzame ubungakanani obunye, obumalunga ne-1/2 intshi ububanzi.
Iindlela zokulungiselela ukufunxa, ukugonyela, ukuvezwa kunye nokubalwa kwekoloni zichazwe kwiimpapasho zethu zangaphambili kwaye zichazwe ngokweenkcukacha kwiDatha eyoNgezelelweyo 11. Ukusebenza kwe-EWNS kuhlolwe ngokutyhila iitumato ezifakwe kwi-incubator kwi-40,000 #/cm3 imizuzu engama-45. Ngamafutshane, ngexesha le-t = 0 min, iitumato ezintathu zasetyenziswa ukuvavanya iintsholongwane ezisindileyo. Iitumato ezintathu zafakwa kwi-EPES zaza zavezwa kwi-EWNS kwi-40,000 #/cc (iitumato ezivezwe yi-EWNS) kwaye ezinye ezintathu zafakwa kwigumbi lolawulo (iitumato zolawulo). Akukho nanye kwiqela leetumato eyaye yaphathwa ngendlela eyongezelelweyo. Iitumato ezivezwe yi-EWNS kunye nolawulo zasuswa emva kwemizuzu engama-45 ukuvavanya isiphumo se-EWNS.
Uvavanyo ngalunye lwenziwe ngokuphindwe kathathu. Uhlalutyo lwedatha lwenziwe ngokwemigaqo echazwe kwiDatha eyoNgezelelweyo.
Iisampulu zebhaktheriya ze-E. coli, i-Enterobacter, kunye ne-L. innocua ezivezwe kwi-EWNS (imizuzu engama-45, uxinaniso lwe-aerosol ye-EWNS engama-40,000 #/cm3) kwaye zingatyhilekanga zaxutywa ukuze kuvavanywe iindlela zokungasebenzi. Ukuncipha kwaqiniswa iiyure ezi-2 kubushushu begumbi kwisisombululo se-sodium cacodylate esingu-0.1 M (pH 7.4) nge-fixative ye-2.5% glutaraldehyde, i-1.25% paraformaldehyde kunye ne-0.03% picric acid. Emva kokuhlamba, zaqiniswa nge-1% osmium tetroxide (OsO4)/1.5% potassium ferrocyanide (KFeCN6) iiyure ezi-2, zahlanjwa izihlandlo ezi-3 ngamanzi zaza zafakwa kwi-1% uranyl acetate iyure e-1, emva koko zahlanjwa kabini ngamanzi. Ukuphelelwa ngamanzi emva koko kuthathwa imizuzu eli-10 nganye ye-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 yegranular yasikwa yaza yabonwa yi-TEM kusetyenziswa i-JEOL 1200EX (JEOL, Tokyo, Japan), imakroskopu ye-transmission electron eqhelekileyo exhotyiswe ngekhamera ye-AMT 2k CCD (Advanced Microscopy Techniques, Corp., Woburn, MA, USA).
Zonke iimvavanyo zenziwe kathathu. Kwinqaku ngalinye lexesha, ukuhlamba iintsholongwane kwabekwa kathathu, nto leyo eyabangela ukuba kubekho amanqaku edatha alithoba ngenqaku ngalinye, umyinge wawo wasetyenziswa njengoxinzelelo lweentsholongwane kuloo nto iphilayo. Ukuphambuka okuqhelekileyo kwasetyenziswa 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 kubalwe xa kuthelekiswa nolawulo lwemizuzu engama-45 ngolu hlobo lulandelayo:
Apho i-Cn iluxinzelelo 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. Kukhethwe iimeko ezimbini zophando olupheleleyo olubonisa iimpawu ezizinzileyo neziphinda kuvele (i-Taylor cone, imveliso ye-EWNS, kunye nozinzo ngokuhamba kwexesha). Kumfanekiso 3 ubonisa iziphumo kwitshaja, ubungakanani kunye nomxholo we-ROS kwiimeko ezimbini. Iziphumo zikwashwankathelwe kwiTheyibhile 1. Njengesalathiso, uMfanekiso 3 kunye neTheyibhile 1 ziquka iimpawu 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 malunga nesiphumo se-counter electrode sampling hole diameter (D) kunye nomgama phakathi kwe-ground electrode kunye nencam yenaliti (L) (Imifanekiso eyoNgezelelweyo S2 kunye ne-S3).
(a–c) Ukusasazwa kobungakanani be-AFM. (d – f) Uphawu lwetshaja yomphezulu. (g) Ukuchazwa kweROS kunye ne-ESR.
Kubalulekile kwakhona ukuqaphela ukuba kuzo zonke ezi meko zingasentla, imisinga ye-ionization elinganisiweyo yayikuluhlu lwe-2-6 µA, kwaye ii-voltage zazikuluhlu lwe--3.8 ukuya kwi--6.5 kV, nto leyo eyabangela ukusetyenziswa kwamandla kwale EWNS yesiphelo esinye esingaphantsi kwe-50 mW. . generation module. 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. Amasimi ngokwe-[-6.5 kV, 4.0 cm] kunye ne-[-3.8 kV, 0.5 cm] abalwa njenge-2 × 105 V/m kunye ne-4.7 × 105 V/m, ngokulandelelana. Oku kulindeleke, kuba umlinganiselo we-voltage kumgama uphezulu kakhulu kwimeko yesibini.
Kumfanekiso 3a, b ubonisa ububanzi be-EWNS obulinganiswe nge-AFM8. Ububanzi obuqhelekileyo be-EWNS beemeko ze-[-6.5 kV, 4.0 cm] kunye ne-[-3.8 kV, 0.5 cm] zibalwe njenge-27 nm kunye ne-19 nm, ngokulandelelana. Ukuphambuka okusemgangathweni kwejometri kokusasazwa kweemeko ze-[-6.5 kV, 4.0 cm] kunye ne-[-3.8 kV, 0.5 cm] yi-1.41 kunye ne-1.45, ngokulandelelana, okubonisa ukusasazwa kobukhulu obuncinci. Zombini ubukhulu obuphakathi kunye nokuphambuka okusemgangathweni kwejometri zisondele kakhulu kwi-baseline-EWNS, ziyi-25 nm kunye ne-1.41, ngokulandelelana. 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], ngokulandelelana. Xa kuthelekiswa ne-Baseline-EWNS (10 ± 2 e-), itshaja yabo yomphezulu iphezulu kakhulu, iphindwe kabini kune-[-6.5 kV, 4.0 cm] kwaye iphindwe kane kune-[-3 .8 kV, 0.5 cm]. I-3f ibonisa idatha yentlawulo esisiseko ye-EWNS.
Kwimephu yoxinaniso lwenani le-EWNS (Imifanekiso eyongezelelweyo S5 kunye ne-S6), kunokubonwa ukuba indawo ye [-6.5 kV, 4.0 cm] inenani eliphezulu kakhulu lamasuntswana kunendawo ye [-3.8 kV, 0.5 cm]. Kufuneka kuqatshelwe ukuba uxinaniso lwenani le-EWNS lubekwe esweni ukuya kuthi ga kwiiyure ezi-4 (Imifanekiso eyongezelelweyo S5 kunye ne-S6), apho uzinzo lwesizukulwana se-EWNS lubonise amanqanaba afanayo oxinaniso lwenani lamasuntswana kuzo zombini iimeko.
Umfanekiso 3g ubonisa i-EPR spectrum emva kokulawula (imvelaphi) ukuthabatha i-EWNS ephuculweyo kwi-[-6.5 kV, 4.0 cm]. I-ROS spectrum ikwathelekiswa ne-EWNS baseline kwiphepha elipapashwe ngaphambili. Inani elibaliweyo le-EWNS elisabela kwi-spin trap yi-7.5 × 104 EWNS/s, efana ne-Baseline-EWNS8 epapashwe ngaphambili. I-EPR spectra ibonise ngokucacileyo ukuba kukho iintlobo ezimbini ze-ROS, apho i-O2- yayininzi, ngelixa i-OH• yayikhona ngobuninzi obuncinci. Ukongeza, uthelekiso oluthe ngqo lwe-peak intensities lubonise ukuba i-EWNS ephuculweyo yayinomxholo we-ROS ophezulu kakhulu xa kuthelekiswa ne-baseline EWNS.
Kumfanekiso 4 ubonisa ukusebenza kakuhle kwe-EWNS kwi-EPES. Idatha ikwashwankathelwe kwiTheyibhile 1 kwaye ithelekiswa nedatha yokuqala ye-EWNS. Kuzo zombini iimeko ze-EUNS, ukufakwa kwe-deposition bekusondele kwi-100% nokuba kukwi-voltage ephantsi ye-3.0 kV. Ngokwesiqhelo, i-3.0 kV yanele ukufikelela kwi-100% yokufakwa kwe-deposition nokuba utshintsho lwe-surface charge lunjani. Phantsi kweemeko ezifanayo, ukusebenza kakuhle kwe-deposition ye-Baseline-EWNS yayiyi-56% kuphela ngenxa ye-charge ephantsi (umyinge wee-electron ezili-10 kwi-EWNS nganye).
Umfanekiso 5 kunye neTheyibhile 2 zishwankathela inqanaba lokungasebenzi kweentsholongwane ezifakwe kwi-incubator phezu kweetamatisi emva kokuvezwa kwi-40,000 #/cm3 EWNS imizuzu engama-45 phantsi kwemeko efanelekileyo [-6.5 kV, 4.0 cm]. I-E. coli kunye ne-L. innocua ezifakwe kwi-incubator zibonise ukwehla okukhulu kwe-3.8 log emva kwemizuzu engama-45 yokuvezwa. Phantsi kweemeko ezifanayo, i-S. enterica ibonise ukwehla okuphantsi kwe-log yee-log ezingama-2.2, ngelixa i-S. cerevisiae kunye ne-M. parafortuitum zibonise ukwehla kwe-log eyi-1.0.
Ii-electron micrographs (Umfanekiso 6) ezibonisa utshintsho oluvela kwi-EWNS kwiiseli ze-E. coli, Salmonella enterica, kunye ne-L. innocua ezikhokelela ekungasebenzini. Iibhaktheriya zokulawula zibonise ii-membrane zeseli ezipheleleyo, ngelixa iibhaktheriya eziveziweyo zonakalisile ii-membrane zangaphandle.
Umfanekiso we-electron microscopic wolawulo kunye neebhaktheriya eziveziweyo ubonise umonakalo kwi-membrane.
Idatha malunga neempawu ze-physicochemical ze-EWNS ezilungisiweyo ngokudibeneyo ibonisa ukuba iimpawu ze-EWNS (itshaja yomphezulu kunye nomxholo we-ROS) ziphuculwe kakhulu xa kuthelekiswa nedatha yesiseko ye-EWNS epapashwe ngaphambili8,9,10,11. Kwelinye icala, ubungakanani bazo buhlale kuluhlu lwe-nanometer, olufana kakhulu neziphumo ezipapashwe ngaphambili, ezivumela ukuba zihlale emoyeni ixesha elide. Ukwanda kwe-polydispersity ebonweyo kunokuchazwa lutshintsho kwitshaja yomphezulu, olumisela ubukhulu besiphumo seRayleigh, ukungacwangciswanga, kunye nokudibana okunokwenzeka kwe-EWNS. Nangona kunjalo, njengoko kuchaziwe nguNielsen et al.22, itshaja yomphezulu ephezulu inciphisa ukufuma ngokunyusa ngempumelelo amandla omphezulu/uxinzelelo lokuwa kwamanzi. Le ngcamango yaqinisekiswa ngovavanyo kwi-microdroplets22 kunye ne-EWNS kupapasho lwethu lwangaphambili8. Ukulahleka kwexesha elongezelelweyo kunokuchaphazela ubungakanani kwaye kunegalelo ekusasazweni kobungakanani obubonwe.
Ukongeza, itshaja ngesakhiwo ngasinye imalunga ne-22–44 e-, kuxhomekeke kwiimeko, nto leyo iphezulu 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.