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I kēia mau lā, ua hoʻomohala ʻia kahi kahua antimicrobial ʻole kemika e pili ana i ka nanotechnology me ka hoʻohana ʻana i nā nanostructures wai artificial (EWNS). He kiʻekiʻe ko ka EWNS a ua waiwai i nā ʻano oxygen reactive (ROS) hiki ke launa pū me ka hoʻopau ʻana i kekahi mau microorganisms, me nā pathogens lawe ʻia i ka meaʻai. Eia ke hōʻike ʻia nei ko lākou mau waiwai i ka wā synthesis hiki ke hoʻoponopono maikaʻi ʻia a hoʻopaʻa ʻia e hoʻomaikaʻi hou i ko lākou hiki antibacterial. Ua hoʻolālā ʻia ke kahua hoʻokolohua EWNS e hoʻoponopono maikaʻi i nā waiwai o EWNS ma o ka hoʻololi ʻana i nā ʻāpana synthesis. Ua hana ʻia ke ʻano o nā waiwai EWNS (ka uku, ka nui, a me ka ʻike ROS) me ka hoʻohana ʻana i nā ʻano analytical hou. Eia kekahi, ua hoʻokomo ʻia nā microorganism meaʻai e like me Escherichia coli, Salmonella enterica, Listeria innocua, Mycobacterium para fortitum, a me Saccharomyces cerevisiae ma luna o ka ʻili o nā tōmato hua waina e loiloi i kā lākou microbial inactivation hiki. Hōʻike nā hopena i hōʻike ʻia ma ʻaneʻi e hiki ke hoʻoponopono maikaʻi ʻia nā waiwai o EWNS i ka wā synthesis, e hopena i ka hoʻonui exponential o ka pono inactivation. ʻO ka mea nui, ua hoʻonui ʻia ka uku o ka ʻili ma kahi helu ʻehā, a ua hoʻonui ʻia ka ʻike ROS. ʻO ka nui o ka wehe ʻana i ka microbial ua hilinaʻi ʻia a mai ka 1.0 a i ka 3.8 log ma hope o 45 mau minuke o ka ʻike ʻana i kahi aerosol dose o 40,000 #/cm3 EWNS.
ʻO ka hoʻohaumia ʻana i ka microbial ke kumu nui o ka maʻi i lawe ʻia e ka meaʻai ma muli o ka ʻai ʻana i nā pathogens a i ʻole kā lākou toxins. Ma kahi o 76 miliona mau maʻi, 325,000 halemai, a me 5,000 make i kēlā me kēia makahiki ma United States wale nō. Eia hou, ke manaʻo nei ke Keʻena ʻOihana Mahiai o ʻAmelika Hui Pū ʻIa (USDA) ʻo ka hoʻonui ʻana i ka ʻai ʻana i nā hua hou ke kuleana no ka 48 pakeneka o nā maʻi lawe ʻai a pau i hōʻike ʻia ma United States2. He kiʻekiʻe loa ke kumukūʻai o ka maʻi a me ka make mai nā pathogens lawe ʻia i ka meaʻai ma ʻAmelika Hui Pū ʻIa, i manaʻo ʻia e nā Centers for Disease Control and Prevention (CDC) ma mua o US $15.6 biliona i kēlā me kēia makahiki3.
I kēia manawa, kemika4, radiation5 a me thermal6 antimicrobial interventions e hōʻoia i ka palekana o ka meaʻai e hoʻokō nui ʻia ma nā palena koʻikoʻi control point (CCPs) i loko o ke kaulahao hana (maʻamau ma hope o ka hōʻiliʻili ʻana a/a i ka wā o ka hoʻopili ʻana) ma mua o ka hoʻokō mau ʻia ʻana i ke ʻano e hiki ai i nā hua hou ke hoʻopōʻino ʻia 7. Liʻiliʻi ka hopena a me ke kumukūʻai.
Ua hoʻomohala ʻia kahi papa hana antimicrobial ʻole kemika i hoʻokumu ʻia i ka nanotechnology no ka hoʻopau ʻana i ka maʻi bacteria ma ka ʻili a me ka lewa me ka hoʻohana ʻana i nā nanostructure wai artificial (EWNS). No ka synthesis o EVNS, ua hoʻohana ʻia ʻelua mau kaʻina hana like: electrospray a me ka wai ionization (Fig. 1a). Ua hōʻike mua ʻia ʻo EWNS i kahi hoʻonohonoho kūʻokoʻa o nā waiwai kino a me ke olaola8,9,10. Loaʻa iā EWNS ka awelika o 10 electrons no kēlā me kēia hale a me ka nui nanometer awelika o 25 nm (Fig. 1b, c) 8,9,10. Eia hou, ua hōʻike ka electron spin resonance (ESR) i ka EWNS he nui ka nui o nā ʻano oxygen reactive (ROS), ka nui o nā radical hydroxyl (OH•) a me superoxide (O2-) (Fig. 1c) 8. Noho ʻo EWNS i ka lewa no ka manawa lōʻihi a hiki ke hui pū me nā microbes i hoʻokuʻu ʻia i ka lewa a hōʻike ʻia ma luna o nā ʻili, e hāʻawi ana i kā lākou uku ROS a hoʻoulu i ka microbial inactivation (Fig. 1d). Ua hōʻike pū ʻia kēia mau haʻawina mua e hiki i ka EWNS ke launa pū me ka hoʻopau ʻana i nā ʻano bacteria gram-negative a me gram-positive o ke koʻikoʻi o ke olakino lehulehu, me ka mycobacteria, ma luna o ka ʻili a me ka lewa8,9. Ua hōʻike ʻia ka microscopy electron transmission i ka hoʻopau ʻia ʻana o ka membrane cell. Eia hou, ua hōʻike ʻia nā haʻawina inhalation nui ʻaʻole e hoʻopōʻino ʻia ka māmā a i ʻole ka mumū ʻana o ka nui o ka EWNS.
(a) Hana ʻia ka Electrospray i ka wā e hoʻohana ʻia ai kahi uila kiʻekiʻe ma waena o kahi capillary i loko o ka wai a me kahi electrode counter. (b) ʻO ka hoʻohana ʻana i ka voluma kiʻekiʻe ka hopena i ʻelua ʻano ʻano like ʻole: (i) electrospraying o ka wai a me (ii) hana o nā ʻano oxygen reactive (ions) i paʻa i ka EWNS. (c) ʻO ke ʻano kū hoʻokahi o EWNS. (d) He paʻa loa ka EWNS ma muli o ko lākou ʻano nanoscale a hiki ke launa pū me nā pathogens ea.
Ua hōʻike ʻia ka hiki o ka EWNS antimicrobial platform ke hoʻopau i nā microorganism i lawe ʻia i ka meaʻai ma ka ʻili o ka meaʻai hou. Ua hōʻike ʻia hoʻi e hiki ke hoʻohana ʻia ka uku o ka ʻili EWNS i hui pū ʻia me kahi kahua uila no ka hoʻouna ʻana. ʻO ka mea nui, ua ʻike ʻia ka hopena mua o ka hoʻemi ʻana i ka 1.4 log i ka hana ʻōmato kūlohelohe e kūʻē i nā microorganism meaʻai like ʻole e like me E. coli a me Listeria i loko o 90 mau minuke o ka ʻike ʻana iā EWNS ma kahi o 50,000#/cm311. Eia kekahi, ʻaʻohe hopena organoleptic i hoʻohālikelike ʻia me ka tomato control. ʻOiai ua hoʻohiki kēia mau hopena inactivation mua i ka palekana o ka meaʻai ma nā haʻahaʻa EWNS haʻahaʻa loa o 50,000#/cc. ʻike, maopopo ka ʻoi aku ka maikaʻi o ka hiki ke hoʻopau ʻia e hōʻemi hou i ka pilikia o ka maʻi a me ka pōʻino.
Ma ʻaneʻi, e kālele mākou i kā mākou noiʻi ʻana i ka hoʻomohala ʻana i kahi kahua o ka hanauna EWNS e hoʻoponopono maikaʻi i nā ʻāpana synthesis a hoʻopaʻa i nā waiwai physicochemical o EWNS e hoʻomaikaʻi i ko lākou hiki ke antibacterial. ʻO ka mea nui, ua kālele ka optimization i ka hoʻonui ʻana i ka uku o ka ʻili (e hoʻomaikaʻi i ka hāʻawi ʻia ʻana) a me ka ʻike ROS (e hoʻomaikaʻi i ka pono inactivation). ʻO ke ʻano o nā waiwai physico-chemical i hoʻopaʻa ʻia (ka nui, ka uku a me ka ʻike ROS) me ka hoʻohana ʻana i nā ʻano analytical hou a me ka hoʻohana ʻana i nā microorganism meaʻai maʻamau e like me E. coli, S. enterica, L. innocua, S. cerevisiae a me M. parafortuitum.
Ua hana ʻia ʻo EVNS e ka electrospraying like a me ka ionization o ka wai maʻemaʻe kiʻekiʻe (18 MΩ cm-1). Hoʻohana maʻamau ka atomizer uila 12 no ka hoʻokahe ʻana i nā wai a me ka polymer synthetic a me nā ʻāpana seramika 13 a me nā fibers 14 o ka nui hoʻomalu.
E like me ka mea kiko'ī ma nā paʻi mua 8, 9, 10, 11, ma kahi hoʻokolohua maʻamau, hoʻohana ʻia kahi voli kiʻekiʻe ma waena o kahi capillary metala a me kahi electrode countered grounded. I loko o kēia kaʻina hana, ʻelua mau hanana like ʻole: 1) electrospray a me 2) ionization o ka wai. ʻO ke kahua uila ikaika ma waena o nā electrodes ʻelua ke kumu o ke kūkulu ʻana i nā kumukūʻai maikaʻi ʻole ma luna o ka ʻili o ka wai i hoʻopaʻa ʻia, ka hopena i ka hoʻokumu ʻana o Taylor cones. ʻO ka hopena, ua hoʻokumu ʻia nā kulu wai i hoʻopiʻi nui ʻia, e hoʻomau ana i ka haki ʻana i mau ʻāpana liʻiliʻi, e like me ka Rayleigh theory16. I ka manawa like, hoʻokaʻawale kekahi o nā molekele wai a wehe i nā electrons (ionization), a laila e hoʻoulu ai i ka nui o nā ʻano oxygen reactive (ROS)17. Hoʻopili ʻia nā ʻeke ROS18 i ka manawa like i EWNS (Fig. 1c).
Ma ka fig. Hōʻike ʻo 2a i ka ʻōnaehana hanauna EWNS i kūkulu ʻia a hoʻohana ʻia i ka synthesis EWNS i kēia haʻawina. ʻO ka wai i hoʻomaʻemaʻe ʻia i mālama ʻia i loko o kahi ʻōmole pani ua hānai ʻia ma o kahi paipu Teflon (2 mm anawaena o loko) i kahi nila kila kuhili ʻole 30G (metal capillary). E like me ka mea i hōʻike ʻia ma ke Kiʻi 2b, mālama ʻia ke kahe o ka wai e ke kaomi ea i loko o ka ʻōmole. Hoʻopili ʻia ka nila i kahi console Teflon hiki ke hoʻoponopono lima ʻia i kahi mamao mai ka electrode counter. ʻO ka counter electrode he pahu alumini i poni ʻia me kahi puka ma waenakonu no ka laʻana. Aia ma lalo o ka electrode counter he funnel sampling aluminika, i hoʻopili ʻia me ke koena o ka hoʻonohonoho hoʻokolohua ma o kahi awa hōʻailona (Fig. 2b). Hoʻokumu ʻia nā ʻāpana sampler a pau i ka uila e pale aku i ka hoʻonui ʻia ʻana o ka uku e hiki ke hoʻohaʻahaʻa i ka laʻana ʻāpana.
(a) Pūnaehana Hana Nanostructure Wai ʻenehana (EWNS). (b) ʻO ka ʻāpana keʻa o ka sampler a me ka ʻāpana electrospray e hōʻike ana i nā ʻāpana koʻikoʻi. (c) Hoʻonohonoho hoʻokolohua no ka hoʻopau ʻana i ka bacteria.
Hiki i ka ʻōnaehana hanauna EWNS i hōʻike ʻia ma luna nei ke hoʻololi i nā ʻāpana hana koʻikoʻi e hoʻomaʻamaʻa i ka hoʻoponopono maikaʻi ʻana i nā waiwai EWNS. E hoʻololi i ka volta i hoʻohana ʻia (V), ka mamao ma waena o ka nila a me ka electrode counter (L), a me ke kahe wai (φ) ma o ka capillary e hoʻoponopono i nā ʻano EWNS. Hoʻohana ʻia nā hōʻailona [V (kV), L (cm)] e hōʻike i nā hui like ʻole. E hoʻololi i ke kahe wai e loaʻa i kahi pahu Taylor paʻa o kekahi pūʻulu [V, L]. No ke kumu o kēia noiʻi ʻana, ua hoʻonohonoho ʻia ka aperture o ka electrode counter (D) ma 0.5 iniha (1.29 knm).
Ma muli o ka palena geometry a me ka asymmetry, ʻaʻole hiki ke helu ʻia ka ikaika o ke kahua uila mai nā kumu mua. Akā, ua hoʻohana ʻia ka polokalamu QuickField™ (Svendborg, Denmark)19 no ka helu ʻana i ke kahua uila. ʻAʻole like ke kahua uila, no laila ua hoʻohana ʻia ka waiwai o ke kahua uila ma ka piko o ka capillary ma ke ʻano he kumu kuhikuhi no nā hoʻonohonoho like ʻole.
I ka wā o ke aʻo ʻana, ua loiloi ʻia kekahi mau hui ʻana o ka volta a me ka mamao ma waena o ka nila a me ka electrode counter e pili ana i ka hoʻokumu ʻana o Taylor cone, Taylor cone stability, EWNS production stability, a reproducibility. Hōʻike ʻia nā hui like ʻole ma ka Papa Pākuʻi S1.
Hoʻopili pololei ʻia ka hoʻopuka o ka ʻōnaehana hanauna EWNS i kahi Scanning Mobility Particle Sizer (SMPS, model 3936, TSI, Shoreview, Minnesota) e ana i ka nui o ka helu particle a ua hoʻohana ʻia me ka Faraday aerosol electrometer (TSI, model 3068B, Shoreview, USA). MN) e ana i nā kahe aerosol, e like me ka mea i wehewehe ʻia ma kā mākou paʻi mua9. Hoʻohālikelike ʻia ka SMPS a me ka electrometer aerosol ma kahi kahe kahe o 0.5 L / min (ka holo ʻana o ka hāpana 1 L / min). Ua ana ʻia ka nui o nā ʻāpana a me nā aerosol no 120 s. E hana hou i ke ana 30 manawa. Ua helu ʻia ka huina aerosol mai nā ana o kēia manawa, a ua manaʻo ʻia ka awelika o ka uku EWNS mai ka huina o nā ʻāpana EWNS i hōʻike ʻia. Hiki ke helu ʻia ke kumukūʻai maʻamau o EWNS me ka hoʻohana ʻana i ka Equation (1):
ma kahi o IEl ke au i ana, o NSMPS ka helu helu i ana me SMPS, a o φEl ke kahe kahe ana i ka electrometer.
Ma muli o ka pili ʻana o ka haʻahaʻa pili (RH) i ka hoʻouka ʻana o ka ʻili, ua mālama mau ʻia ka mahana a me (RH) ma 21°C a me 45%, i ka wā o ka hoʻokolohua.
Ua hoʻohana ʻia ka microscopy Atomic force (AFM), Asylum MFP-3D (Asylum Research, Santa Barbara, CA) a me AC260T probe (Olympus, Tokyo, Iapana) e ana i ka nui a me ke ola o ka EWNS. ʻO ka helu scan AFM he 1 Hz a ʻo ka wahi scan he 5 µm × 5 µm me nā laina scan 256. Hoʻopili ʻia nā kiʻi āpau i ka hoʻonohonoho kiʻi kiʻi mua me ka hoʻohana ʻana i ka polokalamu Asylum (mask me kahi ākea o 100 nm a me kahi paepae o 100 pm).
Wehe i ka funnel sampling a kau i ka ʻili mika ma kahi mamao o 2.0 knm mai ka electrode counter no ka manawa awelika o 120 s e pale aku i ka hui ʻana o nā ʻāpana a me ka hoʻokumu ʻana o nā kulu maʻamau ma luna o ka ʻili mika. Ua hoʻohana pololei ʻia ʻo EWNS i nā ʻili mika i ʻoki hou ʻia (Ted Pella, Redding, CA). Ma hope koke o ka sputtering, ʻike ʻia ka ʻili mika me ka hoʻohana ʻana i ka AFM. ʻO ka huina pili ili o ka mika i ʻoki hou ʻole ʻia ma kahi kokoke i 0°, no laila hoʻolaha ʻo EWNS ma luna o ka ʻili mika ma ke ʻano domed20. Ua ana pololei ʻia ke anawaena (a) a me ke kiʻekiʻe (h) o nā diffusing droplets mai ka topography AFM a hoʻohana ʻia e helu i ka volume diffusion domed EWNS me ka hoʻohana ʻana i kā mākou ala i hōʻoia mua ʻia8. Ke manaʻo nei he like ka leo o ka EVNS ma luna, hiki ke helu ʻia ke anawaena like mai ka hoohalike (2):
E like me kā mākou hana i kūkulu mua ʻia, ua hoʻohana ʻia kahi pahele spin electron spin resonance (ESR) no ka ʻike ʻana i ka hiki ʻana mai o nā intermediates radical pōkole i EWNS. Ua hele ʻia nā Aerosol i loko o kahi hopena i loaʻa ka 235 mM DEPMPO (5-(diethoxyphosphoryl) -5-methyl-1-pyrroline-N-oxide) (Oxis International Inc., Portland, Oregon). Hoʻohana ʻia nā ana EPR a pau me ka Bruker EMX spectrometer (Bruker Instruments Inc. Billerica, MA, USA) a me nā ʻāpana cell flat. Ua hoʻohana ʻia ka polokalamu Acquisit (Bruker Instruments Inc. Billerica, MA, USA) no ka hōʻiliʻili ʻana a me ka nānā ʻana i ka ʻikepili. Ua hana ʻia ka hōʻike ROS no kahi hoʻonohonoho o nā kūlana hana [-6.5 kV, 4.0 cm]. Ua ana ʻia nā manaʻo EWNS me ka SMPS ma hope o ka noʻonoʻo ʻana i ka nalowale o ka EWNS i ka hopena.
Ua nānā ʻia nā pae Ozone me ka 205 Dual Beam Ozone Monitor™ (2B Technologies, Boulder, Co)8,9,10.
No nā waiwai EWNS a pau, ʻo ke ana ʻana ke ʻano o nā ana, a ʻo ka hewa ana ʻana ʻo ia ka ʻokoʻa maʻamau. Ua hana ʻia kahi hoʻāʻo-t e hoʻohālikelike i ka waiwai o ka ʻano EWNS i hoʻopaʻa ʻia me ka waiwai kūpono o ka EWNS kumu.
Hōʻike ka Figure 2c i kahi Electrostatic Precipitation Pass Through System (EPES) i kūkulu mua ʻia a i ʻike ʻia i hiki ke hoʻohana ʻia no ka huli ʻana i ka EWNS11 i nā ʻili. Hoʻohana ʻo EPES i ka uku EWNS i hui pū ʻia me kahi kahua uila ikaika e "kuhikuhi" pololei ma ka ʻili o ka mea i paʻi ʻia. Hōʻike ʻia nā kikoʻī o ka ʻōnaehana EPES ma kahi paʻi hou e Pyrgiotakis et al.11. No laila, aia ka EPES i kahi keʻena PVC paʻi 3D me nā ʻaoʻao tapered i loaʻa i ʻelua mau mea kila kuhili ʻole (304 stainless steel, aniani poli i hoʻoliʻi ʻia) ma ka waena 15.24 knm kaawale. Hoʻopili ʻia nā papa i kahi puna uila kiʻekiʻe o waho (Bertran 205B-10R, Spellman, Hauppauge, NY), ua maikaʻi mau ka papa lalo a ua paʻa mau ka papa luna (nānā). Ua uhi ʻia nā paia o ke keʻena me ka alumini alumini, i hoʻopaʻa ʻia i ka uila e pale ai i ka nalo ʻana. Aia ka keena i ka puka hoʻouka mua i hoʻopaʻa ʻia e hiki ai ke kau ʻia nā ʻili hoʻāʻo ma luna o nā pahu plastik, e hoʻokiʻekiʻe iā lākou mai ka pā metala lalo e pale aku i ka hoʻopili uila kiʻekiʻe.
Ua helu ʻia ka maikaʻi o ka deposition o EWNS ma EPES e like me kahi protocol i kūkulu mua ʻia i kikoʻī ʻia ma ke Kiʻi S111.
Ma keʻano he keʻena hoʻomalu, ua hoʻohuiʻia ka lua o ke kahe i loko o ke keʻena cylindrical me ka pūnaewele EPES me ka hoʻohanaʻana i kahi kānana HEPA waena e wehe iā EWNS. E like me ka hoike ana ma ka fig. 2c, ua puhi ʻia ka aerosol EWNS ma nā keʻena ʻelua i hoʻopili ʻia i ka series. Hoʻopau ka kānana ma waena o ka lumi hoʻomalu a me EPES i nā EWNS i koe e hopena i ka mahana like (T), ka haʻahaʻa pili (RH) a me nā pae ozone.
Ua ʻike ʻia nā microorganism meaʻai nui e hoʻohaumia i nā hua hou e like me Escherichia coli (ATCC #27325), he hōʻailona fecal, Salmonella enterica (ATCC #53647), he pathogen lawe ʻai i ka meaʻai, Listeria innocua (ATCC #33090), he mea ʻokoʻa i ka pathogenic Listeria monocytogenes. , Saccharomyces cerevisiae (ATCC #4098) ma ke ʻano he ʻokoʻa i ka hū spoilage, a ʻo Mycobacterium parafortuitous (ATCC #19686) ma ke ʻano he bacteria ola kūʻokoʻa i kūʻai ʻia mai ATCC (Manassas, Virginia).
E kūʻai maʻamau i nā pahu o nā tōmato hua waina mai kou mākeke kūloko a hoʻopaʻa i ka pahu hau ma 4°C a hiki i ka hoʻohana ʻana (a hiki i 3 lā). E koho i nā tōmato e hoʻokolohua me ka nui hoʻokahi, ma kahi o 1/2 iniha ke anawaena.
ʻO nā protocols no ka incubation, inoculation, exposure and colony counting ua kikoʻī ʻia i loko o kā mākou mau puke i hala a wehewehe ʻia i nā kikoʻī ma ka ʻikepili Hoʻohui 11. Ua loiloi ʻia ka hana EWNS ma ka hoʻolaha ʻana i nā tōmato inoculated i 40,000 #/cm3 no 45 mau minuke. ʻO ka pōkole, i ka manawa t = 0 min, ua hoʻohana ʻia ʻekolu mau tōmato e loiloi i nā microorganism e ola nei. Hoʻokomo ʻia ʻekolu tōmato ma EPES a hōʻike ʻia iā EWNS ma 40,000 #/cc (EWNS exposed tomatoes) a ʻekolu mau mea ʻē aʻe i hoʻokomo ʻia i loko o ke keʻena hoʻomalu (control tomatoes). ʻAʻohe o nā pūʻulu tōmato i hoʻokō ʻia i ka hana hou. Ua wehe ʻia nā ʻōmato a me nā mana i hōʻike ʻia e EWNS ma hope o 45 mau minuke e loiloi i ka hopena o EWNS.
Ua hana ʻia kēlā me kēia hoʻokolohua ʻekolu. Hana ʻia ka ʻikepili ʻikepili e like me ka protocol i wehewehe ʻia ma ka ʻikepili Hoʻohui.
ʻO E. coli, Enterobacter, a me L. innocua bacterial samples i hōʻike ʻia i ka EWNS (45 min, EWNS aerosol concentration 40,000 #/cm3) a me ka wehe ʻole ʻia ua pelleted e loiloi i nā hana inactivation. Ua hoʻopaʻa ʻia ka precipitate no 2 mau hola ma ka lumi wela ma 0.1 M sodium cacodylate solution (pH 7.4) me kahi fixative o 2.5% glutaraldehyde, 1.25% paraformaldehyde a me 0.03% picric acid. Ma hope o ka holoiʻana, ua hoʻopaʻaʻia lākou me ka 1% osmium tetroxide (OsO4) / 1.5% potassium ferrocyanide (KFeCN6) no 2 h, holoiʻia i 3 manawa me ka wai a hoʻokomo i ka 1% uranyl acetate no 1 h, a laila holoi iʻelua manawa me ka wai. Ma hope o dehydration 10 minuke kēlā me kēia o 50%, 70%, 90%, 100% waiʻona. Hoʻokomo ʻia nā laʻana i loko o ka propylene oxide no ka hola 1 a hoʻopaʻa ʻia me kahi hui 1: 1 o propylene oxide a me TAAP Epon (Marivac Canada Inc. St. Laurent, CA). Hoʻokomo ʻia nā laʻana i loko o TAAB Epon a polymerized ma 60 ° C no 48 mau hola. Ua ʻoki ʻia ka resin granular i hoʻōla ʻia e TEM me ka hoʻohana ʻana i kahi JEOL 1200EX (JEOL, Tokyo, Iapana), kahi microscope electron transmission maʻamau i lako me kahi kāmela AMT 2k CCD (Advanced Microscopy Techniques, Corp., Woburn, MA, USA).
Ua hana ʻia nā hoʻokolohua ʻekolu. No kēlā me kēia manawa, ua uhi ʻia ka holoi maʻi bacteria ma ke ʻano ʻekolu, e loaʻa ana ka huina o ʻeiwa mau helu ʻikepili i kēlā me kēia kiko, ʻo ka awelika o ia mea i hoʻohana ʻia ma ke ʻano he kumu bacteria no kēlā mea ola. Ua hoʻohana ʻia ka ʻokoʻa maʻamau e like me ke ana hewa. helu nā helu a pau.
Ua helu ʻia ka logarithm o ka emi ʻana o ka neʻe ʻana o ka bacteria i hoʻohālikelike ʻia me ka t = 0 min me ka hoʻohana ʻana i kēia ʻano:
ʻo ka C0 ka neʻe ʻana o ka hua bacteria i ka hāpana hoʻomalu i ka manawa 0 (ʻo ia hoʻi ma hope o ka maloʻo ʻana o ka ʻili akā ma mua o ka waiho ʻia ʻana i loko o ke keʻena) a ʻo Cn ka neʻe ʻana o ka maʻi bacteria ma ka ʻili ma hope o n mau minuke o ka ʻike.
No ka helu ʻana i ka hoʻohaʻahaʻa maoli ʻana o ka maʻi bacteria i ka manawa hōʻike 45 mau minuke, ua helu pū ʻia ʻo Log-Reduction i hoʻohālikelike ʻia me ka mana ma 45 mau minuke penei:
ʻO ka Cn ka ʻike o ka bacteria i ka hāpana hoʻomalu i ka manawa n a ʻo ka Cn-Control ka ʻike o ka bacteria mana i ka manawa n. Hōʻike ʻia ka ʻikepili ma ke ʻano he hōʻemi log i hoʻohālikelike ʻia me ka mana (ʻaʻohe hōʻike EWNS).
I ka wā o ke aʻo ʻana, ua loiloi ʻia kekahi mau hui ʻana o ka volta a me ka mamao ma waena o ka nila a me ka electrode counter e pili ana i ka hoʻokumu ʻana o Taylor cone, Taylor cone stability, EWNS production stability, a reproducibility. Hōʻike ʻia nā hui like ʻole ma ka Papa Pākuʻi S1. Ua koho ʻia ʻelua mau hihia no kahi haʻawina piha e hōʻike ana i nā waiwai paʻa a reproducible (Taylor cone, hana EWNS, a me ke kūpaʻa i ka manawa). Ma ka fig. Hōʻike ka 3 i nā hopena ma ka uku, ka nui a me ka ʻike o ROS no nā hihia ʻelua. Ua hōʻuluʻulu ʻia nā hopena ma ka Papa 1. No ka ʻike, ʻo ka Figure 3 a me ka Papa 1 nā waiwai o ka EWNS8, 9, 10, 11 (baseline-EWNS) i hana mua ʻia. Hoʻopuka hou ʻia nā helu helu koʻikoʻi e hoʻohana ana i ka hoʻāʻo t-huelo ʻelua ma ka Papa Pākuʻi S2. Eia kekahi, ʻo nā ʻikepili hou e pili ana i nā haʻawina e pili ana i ka hopena o ka counter electrode sampling hole diameter (D) a me ka mamao ma waena o ka electrode honua a me ka piko o ka nila (L) (Nā Kiʻi Hoʻohui S2 a me S3).
(a–c) puunaue nui AFM. (d – f) ʻO ke ʻano hoʻoili o ka ʻili. (g) Ke ano o ROS a me ESR.
He mea nui nō hoʻi e hoʻomaopopo ʻia no nā kūlana a pau i luna, aia nā au ionization i ana ʻia ma ka laulā o 2-6 µA, a aia nā voltages i ka laulā o -3.8 a i -6.5 kV, ka hopena i ka hoʻohana ʻana i ka mana no kēia EWNS hoʻokahi-terminal o lalo o 50 mW. . module hanauna. ʻOiai ua hana ʻia ʻo EWNS ma lalo o ke kaomi kiʻekiʻe, haʻahaʻa loa nā pae ozone, ʻaʻole i ʻoi aku ma mua o 60 ppb.
Hōʻike ke Kiʻi S4 hou i nā kahua uila i hoʻohālikelike ʻia no nā hiʻohiʻona [-6.5 kV, 4.0 knm] a me [-3.8 kV, 0.5 knm]. ʻO nā māla e like me nā hiʻohiʻona [-6.5 kV, 4.0 cm] a me [-3.8 kV, 0.5 cm] ua helu ʻia ʻo 2 × 105 V/m a me 4.7 × 105 V/m. Pono kēia e manaʻo ʻia, no ka mea, ʻoi aku ka kiʻekiʻe o ka ratio o ka volta i ka mamao ma ka hihia ʻelua.
Ma ka fig. Hōʻike ka 3a, b i ke anawaena EWNS i ana ʻia me ka AFM8. ʻO nā anawaena EWNS maʻamau no nā hiʻohiʻona [-6.5 kV, 4.0 knm] a me [-3.8 kV, 0.5 knm] i helu ʻia he 27 nm a me 19 nm. ʻO nā hoʻokaʻawale maʻamau geometric o nā puʻunaue no nā hihia [-6.5 kV, 4.0 cm] a me [-3.8 kV, 0.5 cm] he 1.41 a me 1.45, e hōʻike ana i kahi puʻunaue haiki. ʻO ka mean nui a me ka geometric standard deviation kokoke loa i ka baseline-EWNS, ʻo 25 nm a me 1.41. Ma ka fig. Hōʻike ka 3c i ka puʻunaue nui o ka baseline EWNS i ana ʻia me ke ʻano like ma lalo o nā kūlana like.
Ma ka fig. Hōʻike ʻo 3d,e i nā hopena o ke ʻano o ka uku. ʻO ka ʻikepili nā ana awelika o 30 mau ana like o ka ʻike (#/cm3) a me kēia manawa (I). Hōʻike ka hōʻike ʻana he 22 ± 6 e- a me 44 ± 6 e- no ka [-6.5 kV, 4.0 knm] a me [-3.8 kV, 0.5 knm] ka awelika uku ma ka EWNS. Ke hoʻohālikelike ʻia me Baseline-EWNS (10 ± 2 e-), ʻoi aku ka kiʻekiʻe o ko lākou hoʻouka ʻana i ka ʻili, ʻelua ʻelua o ko ka [-6.5 kV, 4.0 knm] hiʻohiʻona a ʻehā manawa o ka [-3 .8 kV, 0.5 cm]. Hōʻike ʻo 3f i ka ʻikepili uku EWNS maʻamau.
Mai nā palapala ʻāina hoʻopaʻa helu EWNS (Supplementary Figures S5 a me S6), hiki ke ʻike ʻia he ʻoi aku ka nui o ka [-6.5 kV, 4.0 knm] hiʻohiʻona ma mua o ka [-3.8 kV, 0.5 knm]. Pono e hoʻomaopopo ʻia ua nānā ʻia nā helu helu EWNS a hiki i 4 mau hola (Nā Kiʻi Hoʻohui S5 a me S6), kahi i hōʻike ʻia ai ka paʻa ʻana o ka hanauna EWNS i nā pae like o ka nui o nā helu helu i nā hihia ʻelua.
Hōʻike ka Figure 3g i ka spectrum EPR ma hope o ka unuhi ʻana i ka mana (background) no ka EWNS i hoʻopaʻa ʻia ma [-6.5 kV, 4.0 cm]. Hoʻohālikelike ʻia ka spectrum ROS me ka baseline EWNS ma kahi pepa i paʻi mua ʻia. He 7.5 × 104 EWNS/s ka helu helu o EWNS e pane ana me ka pahele milo, e like me ka Baseline-EWNS8 i paʻi mua ʻia. Ua hōʻike maopopo ʻia ka spectra EPR i ka loaʻa ʻana o nā ʻano ROS ʻelua, kahi o O2- i mana nui, ʻoiai ʻo OH• aia ma kahi liʻiliʻi. Eia kekahi, ua hōʻike ʻia kahi hoʻohālikelike pololei o ka ikaika kiʻekiʻe i ka EWNS i hoʻopaʻa ʻia i ka ʻike ROS kiʻekiʻe loa i hoʻohālikelike ʻia i ka baseline EWNS.
Ma ka fig. Hōʻike ka 4 i ka pono o ka waiho ʻana o EWNS ma EPES. Ua hōʻuluʻulu ʻia nā ʻikepili ma ka Papa I a hoʻohālikelike ʻia me ka ʻikepili EWNS kumu. No nā hihia EUNS ʻelua, kokoke i ka 100% ka waiho ʻana ma kahi haʻahaʻa haʻahaʻa o 3.0 kV. ʻO ka maʻamau, lawa ka 3.0 kV no ka hoʻokō ʻana i ka 100% deposition me ka nānā ʻole i ka hoʻololi ʻana o ka uku o ka ʻili. Ma lalo o nā kūlana like, ʻo 56% wale nō ka deposition pono o ka Baseline-EWNS ma muli o ka haʻahaʻa haʻahaʻa (awelika 10 electrons no EWNS).
Hōʻuluʻulu ka Figure 5 a me ka Papa 2 i ke kiʻekiʻe o ka inactivation o nā microorganism i hoʻopaʻa ʻia ma ka ʻili o nā tōmato ma hope o ka hoʻolaha ʻana i kahi 40,000 #/cm3 EWNS no 45 mau minuke ma lalo o ke kūlana maikaʻi loa [-6.5 kV, 4.0 cm]. Ua hōʻike ʻo Inoculated E. coli a me L. innocua i kahi hōʻemi nui o 3.8 log ma hope o 45 mau minuke o ka ʻike. Ma lalo o nā kūlana like, ua hōʻike ʻo S. enterica i kahi hōʻemi haʻahaʻa o ka log 2.2, ʻoiai ʻo S. cerevisiae a me M. parafortuitum i hōʻike i kahi hōʻemi 1.0 log.
Electron micrographs (Figure 6) e hōʻike ana i nā hoʻololi kino i hoʻoulu ʻia e EWNS i loko o E. coli, Salmonella enterica, a me L. innocua mau pūnaewele e alakaʻi ana i ka inactivation. Hōʻike ka bacteria control i nā membrane cell paʻa, ʻoiai ua hōʻino nā bacteria i hōʻike ʻia i nā membrane waho.
Ua hōʻike ʻia ke kiʻi microscopic electron o ka mana a me ka bacteria i hōʻike ʻia i ka pōʻino membrane.
ʻO kaʻikepili e pili ana i nā waiwai physicochemical o ka EWNS i hoʻopaʻaʻia e hōʻike pū ana ua hoʻonui maikaʻiʻia nā waiwai EWNS (ka hoʻoiliʻana a me ka ROS content) i ka hoʻohālikelikeʻana i ka EWNS baseline data8,9,10,11 i paʻi muaʻia. Ma kekahiʻaoʻao, ua mau ko lākou nui i loko o ka nanometer range, i like loa me nā hualoaʻa i paʻi muaʻia, e hiki ai iā lākou ke noho i ka lewa no ka manawa lōʻihi. Hiki ke wehewehe ʻia ka polydispersity i ʻike ʻia e ka hoʻololi ʻana i ka uku o ka ʻili, ka mea e hoʻoholo ai i ka nui o ka hopena Rayleigh, randomness, a me ka hoʻohui ʻana o EWNS. Eia naʻe, e like me ka kikoʻī e Nielsen et al.22, hoʻemi ʻia ka hoʻoheheʻe ʻana o ka ʻili kiʻekiʻe ma o ka hoʻonui pono ʻana i ka ikehu o ka ili o ka wai. Ua hōʻoia ʻia kēia kumumanaʻo no nā microdroplets22 a me EWNS i kā mākou paʻi mua8. Hiki ke hoʻololi i ka nui o ka nalo ʻana o ka manawa lōʻihi a kōkua i ka puʻunaue nui i ʻike ʻia.
Eia kekahi, ʻo ka uku no kēlā me kēia hale ma kahi o 22-44 e-, e pili ana i nā kūlana, ʻoi aku ka kiʻekiʻe ma mua o ka EWNS kumu, nona ka awelika o 10 ± 2 electrons no kēlā me kēia hale. Eia naʻe, pono e hoʻomaopopo ʻia ʻo ia ka uku maʻamau o EWNS. Seto et al. Ua hōʻike ʻia ʻaʻole kūlike ka uku a hahai i ka puunaue log-maʻamau21. Hoʻohālikelike ʻia me kā mākou hana mua, ʻo ka pālua ʻana i ka uku o ka ʻili e pāpālua i ka pono o ka waiho ʻana ma ka ʻōnaehana EPES a kokoke i 100%11.