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Munguva pfupi yapfuura, puratifomu isina mishonga inorwisa utachiona yakavakirwa pa nanotechnology inoshandisa nanostructures dzemvura dzekugadzira (EWNS) yakagadzirwa. EWNS ine simba guru pamusoro uye ine mhando dzeoxygen dzinoshanda (ROS) dzinogona kusangana nehutachiona hwakawanda, kusanganisira hutachiona hwechikafu. Pano zvinoratidzwa kuti hunhu hwavo panguva yekugadzira hunogona kugadziriswa zvakanaka uye kugadziriswa kuti huwedzere simba ravo rekurwisa utachiona. Puratifomu yerabhoritari yeEWNS yakagadzirwa kuti igadzirise hunhu hweEWNS nekushandura maparamita ekugadzira. Kutsanangurwa kwehunhu hweEWNS (charge, saizi, uye ROS) kwakaitwa uchishandisa nzira dzemazuva ano dzekuongorora. Pamusoro pezvo, hutachiona hwechikafu hwakadai seEscherichia coli, Salmonella enterica, Listeria innocua, Mycobacterium para fortitum, uye Saccharomyces cerevisiae hwakaiswa pamusoro pematomatisi emazambiringa eorganic kuti vaongorore kugona kwavo kwekudzivirira utachiona. Mhedzisiro yakapihwa pano inoratidza kuti hunhu hweEWNS hunogona kugadziriswa zvakanaka panguva yekugadzira, zvichikonzera kuwedzera kukuru mukushanda kwekudzivirira. Zvikuru sei, simba repamusoro rakawedzera nekachina, uye huwandu hweROS hwakawedzera. Mwero wekubviswa kwehutachiona waienderana nehutachiona uye waitangira pa1.0 kusvika 3.8 log mushure memaminitsi makumi mana nemashanu ekubatwa neaerosol dose ye40,000 #/cm3 EWNS.
Kusvibiswa kwehutachiona ndiko kunonyanya kukonzera zvirwere zvinokonzerwa nekudya zvinokonzerwa nekunwa utachiona kana chepfu yahwo. Zvirwere zvinokonzerwa nekudya zvinokonzera zvirwere zvinosvika mamiriyoni makumi manomwe nematanhatu, 325,000 zviri muchipatara, uye 5,000 vanofa gore rega rega muUnited States chete1. Pamusoro pezvo, United States Department of Agriculture (USDA) inofungidzira kuti kuwedzerwa kwekudya zvirimwa zvitsva ndiko kunokonzera 48 muzana yezvirwere zvese zvinokonzerwa nekudya zvakashumwa muUnited States2. Mutengo wekurwara nerufu zvichibva kuzvirwere zvinokonzerwa nekudya muUnited States wakakwira zvikuru, unofungidzirwa neCenters for Disease Control and Prevention (CDC) kuti upfuure US$15.6 bhiriyoni pagore3.
Parizvino, mishonga inorwisa utachiona yemakemikari4, radiation5 uye thermal6 yekuona kuti chikafu chakachengeteka inonyanya kuitwa panzvimbo dzakaganhurirwa dzekudzora (CCPs) muchikamu chekugadzira (kazhinji mushure mekukohwa uye/kana panguva yekurongedza) pane kugara ichishandiswa nenzira yekuti zvirimwa zvitsva zvinogona kusvibiswa nemarudzi akasiyana-siyana. 7. Mishonga inorwisa utachiona inodiwa kuti idzore zviri nani zvirwere zvinokonzerwa nechikafu uye kuora kwechikafu uye ine mukana wekushandiswa munzvimbo dzese dzepurazi. Kukanganisa kushoma uye mutengo wakaderera.
Nzvimbo yemakemikari isina mabhakitiriya yakavakirwa pa nanotechnology yakagadziridzwa munguva pfupi yapfuura kuti ibvise mabhakitiriya pamusoro nepamhepo uchishandisa ma nanostructures emvura ekugadzira (EWNS). Pakugadzira EVNS, maitiro maviri akafanana akashandiswa: electrospray uye water ionization (Mufananidzo 1a). EWNS dzakamboratidzwa kuti dzine seti yakasiyana yehunhu hwepanyama nehwepamuviri8,9,10. EWNS ine avhareji yemaerekitironi gumi pachivakwa chimwe nechimwe uye avhareji yehukuru hwenanometer ye25 nm (Mufananidzo 1b,c)8,9,10. Pamusoro pezvo, electron spin resonance (ESR) yakaratidza kuti EWNS ine huwandu hwakawanda hwe reactive oxygen species (ROS), kunyanya hydroxyl (OH•) uye superoxide (O2-) radicals (Mufananidzo 1c)8. EWNS yakaramba iri mumhepo kwenguva yakareba uye inogona kurovera nehutachiona hwakamiswa mumhepo uye huripo pamusoro, ichipa ROS payload yavo uye ichikonzera kusashanda kwehutachiona (Mufananidzo 1d). Zvidzidzo izvi zvekare zvakaratidzawo kuti EWNS inogona kusangana nekubvisa mabhakitiriya akasiyana-siyana ane gram-negative uye gram-positive akakosha pahutano hwevanhu, kusanganisira mycobacteria, pamusoro uye mumhepo8,9. Kuongororwa kwema electron microscopy kwakaratidza kuti kudzima kwacho kwakakonzerwa nekukanganiswa kwe membrane yesero. Pamusoro pezvo, zvidzidzo zvekufema zvakaratidza kuti huwandu hwakawanda hweEWNS hahukonzeri kukuvara kwemapapu kana kuzvimba8.
(a) Kupfapfaidza kwemagetsi kunoitika kana simba remagetsi rakakwira rakaiswa pakati pemvura ine capillary ne counter electrode. (b) Kushandiswa kwesimba remagetsi rakakwira kunoguma nezvinhu zviviri zvakasiyana: (i) kupfapfaidza kwemvura nemagetsi uye (ii) kugadzirwa kwemhando dzeokisijeni dzinoshanda (ions) dzakabatwa muEWNS. (c) Maumbirwo akasiyana eEWNS. (d) EWNS dzinofamba zvakanyanya nekuda kwehunhu hwadzo hwe nanoscale uye dzinogona kusangana nezvirwere zvinotapukira zviri mumhepo.
Kukwanisa kwepuratifomu yeEWNS inorwisa utachiona kudzima tupukanana tunobva muchikafu pamusoro pechikafu chitsva kwakaratidzwawo munguva pfupi yapfuura. Zvakaratidzwawo kuti simba reEWNS rinogona kushandiswa pamwe chete nemagetsi kuti risvike zvakananga. Chinonyanya kukosha ndechekuti, mhedzisiro yekutanga inovimbisa yekudzikira kweinenge 1.4 log mukushanda kwematomatisi eorganic kurwisa tupukanana twakasiyana-siyana twechikafu senge E. coli neListeria yakaonekwa mukati memaminitsi makumi mapfumbamwe mushure mekusangana neEWNS nehuwandu hweinenge 50,000#/cm311. Pamusoro pezvo, bvunzo dzekutanga dzekuongorora organoleptic hadzina kuratidza mhedzisiro ye organoleptic zvichienzaniswa nematomatisi ekudzora. Kunyangwe izvi zvekutanga zvekumisa tupukanana zvichivimbisa kuchengetedzeka kwechikafu kunyangwe pamadhora mashoma eEWNS e50,000#/cc. ona, zviri pachena kuti mukana wepamusoro wekumisa tupukanana waizobatsira zvakanyanya kuderedza njodzi yehutachiona nekuora.
Pano, tichatarisa tsvakiridzo yedu pakugadzira puratifomu yekugadzira EWNS kuti tigadzirise maparamita ekugadzira uye kugadzirisa hunhu hwefizikisi yeEWNS kuti iwedzere kugona kwayo kurwisa mabhakitiriya. Kunyanya, kugadzirisa kwakatarisana nekuwedzera simba rayo repamusoro (kuvandudza kuendeswa kwakatarwa) uye huwandu hweROS (kuvandudza kushanda zvakanaka kwekusashanda). Kutsanangurwa kwehunhu hwefizikisi-kemikari hwakagadziriswa (hukuru, simba uye huwandu hweROS) uchishandisa nzira dzemazuva ano dzekuongorora uye kushandisa tupukanana twakajairika mukudya senge E. coli, S. enterica, L. innocua, S. cerevisiae uye M. parafortuitum.
EVNS yakagadzirwa nekupfapfaidza nemagetsi panguva imwe chete uye kuisa mvura yakachena (18 MΩ cm–1). Atomizer yemagetsi 12 inowanzo shandiswa kugadzira atomi yezvinwiwa uye synthetic polymer uye ceramic particles 13 uye fibers 14 yehukuru hwakadzorwa.
Sezvakatsanangurwa muzvinyorwa zvekare 8, 9, 10, 11, mukuyedza kwakajairika, voltage yakakwira inoshandiswa pakati pesimbi capillary ne grounded counter electrode. Munguva iyi, zviitiko zviviri zvakasiyana zvinoitika: 1) electrospray uye 2) ionization yemvura. Simba remagetsi rakasimba pakati pema electrodes maviri rinokonzera kuti negative charges iungane pamusoro pemvura yakakomberedzwa, zvichikonzera kuumbwa kwemaTaylor cones. Nekuda kweizvozvo, madonhwe emvura ane chaji yakawanda anoumbwa, ayo anoramba achipatsanuka kuita zvidimbu zvidiki, zvichienderana nedzidziso yeRayleigh16. Panguva imwe chete, simba remagetsi rakasimba rinoita kuti mamwe mamorekuru emvura apatsanuke uye abvise maerekitironi (ionization), nokudaro achigadzira huwandu hwakawanda hwe reactive oxygen species (ROS)17. Mapaketi eROS18 akagadzirwa panguva imwe chete akaiswa muEWNS (Mufananidzo 1c).
Pamufananidzo 2a panoratidza nzira yekugadzira EWNS yakagadzirwa uye yakashandiswa mukugadzirwa kweEWNS muchidzidzo ichi. Mvura yakachena yakachengetwa mubhodhoro rakavharwa yakaendeswa kuburikidza nechubhu yeTeflon (dhayamita yemukati ye2 mm) kune tsono yesimbi isina ngura ye30G (capillary yesimbi). Sezvakaratidzwa muMufananidzo 2b, kuyerera kwemvura kunodzorwa nekumanikidzwa kwemhepo mukati mebhodhoro. Tsono yakabatanidzwa kune Teflon console inogona kugadziriswa nemaoko kusvika kure kubva ku counter electrode. Count electrode idiski yealuminium yakaporishwa ine gomba pakati pekutora sampling. Pasi pe counter electrode pane funnel yealuminium sampling, iyo yakabatana kune zvimwe zvese zvekuyedza kuburikidza nechiteshi chesampling (Mufananidzo 2b). Zvikamu zvese zvesampler zvakagadzikwa nemagetsi kudzivirira kuunganidza chaji kunogona kukanganisa sampling yezvikamu.
(a) Sisitimu yekugadzira mvura ine mainjiniya (EWNS). (b) Chikamu chemusanganiswa wesampler ne electrospray unit chinoratidza maparameter akakosha. (c) Kugadzirira kwekuyedza kwekusashanda kwebhakitiriya.
Sisitimu yekugadzira EWNS yakatsanangurwa pamusoro apa inokwanisa kuchinja ma parameter ekushanda akakosha kuti zvive nyore kugadzirisa zvakanaka hunhu hweEWNS. Gadzirisa voltage inoshandiswa (V), daro riri pakati petsono ne counter electrode (L), uye kuyerera kwemvura (φ) kuburikidza ne capillary kuti igadzirise hunhu hweEWNS. Zviratidzo [V (kV), L (cm)] zvinoshandiswa kuratidza musanganiswa wakasiyana. Gadzirisa kuyerera kwemvura kuti uwane Taylor cone yakagadzikana yeimwe seti [V, L]. Pachinangwa chechidzidzo ichi, aperture ye counter electrode (D) yakaiswa pa 0.5 inches (1.29 cm).
Nekuda kwe geometry shoma uye kusaenzana, simba remagetsi harigone kuverengerwa kubva pamisimboti yekutanga. Pane kudaro, software yeQuickField™ (Svendborg, Denmark)19 yakashandiswa kuverenga magetsi. Magetsi haana kufanana, saka kukosha kwemagetsi ari pamucheto we capillary kwakashandiswa sereferensi yemaitiro akasiyana-siyana.
Munguva yekudzidza, kusanganiswa kwakawanda kwemagetsi uye daro riri pakati petsono ne counter electrode kwakaongororwa maererano nekuumbwa kweTaylor cone, kugadzikana kweTaylor cone, kugadzikana kwekugadzirwa kweEWNS, uye kugona kudzokororwa. Kusanganiswa kwakasiyana-siyana kunoratidzwa muSupplementary Table S1.
Kubuda kwehurongwa hwekugadzira EWNS kwakabatana zvakananga neScanning Mobility Particle Sizer (SMPS, model 3936, TSI, Shoreview, Minnesota) kuyera huwandu hwe particle number uye kwakashandiswa neFaraday aerosol electrometer (TSI, model 3068B, Shoreview, USA). MN) kuyera kuyerera kwe aerosol, sezvakatsanangurwa mubhuku redu rekare9. SMPS ne aerosol electrometer zvakatorwa pa flow rate ye 0.5 L/min (total sample flow 1 L/min). Particle concentrations ne aerosol fluxes zvakayerwa kwe 120 seconds. Dzokorora kuyerwa ka30. Total aerosol charge inoverengwa kubva pa current measurements, uye avhareji ye EWNS charge inofungidzirwa kubva pahuwandu hwe EWNS particles dzakatorwa. Avhareji yemari ye EWNS inogona kuverengerwa uchishandisa Equation (1):
apo IEl ndiyo current yakayerwa, NSMPS ndiyo nhamba inoyerwa neSMPS, uye φEl ndiyo flow rate kuenda kuelectrometer.
Nekuti hunyoro (RH) hunokanganisa simba repamusoro, tembiricha uye (RH) zvakachengetwa zvakafanana pa21°C uye 45%, zvichiteerana, panguva yekuyedza.
Michina yeAtomic force microscopy (AFM), Asylum MFP-3D (Asylum Research, Santa Barbara, CA) uye AC260T probe (Olympus, Tokyo, Japan) zvakashandiswa kuyera saizi uye hupenyu hweEWNS. Chiyero cheAFM scan i1 Hz uye nzvimbo yekuskena i5 µm×5 µm ine mitsara yekuskena 256. Mifananidzo yese yakagadziriswa first order image alignment uchishandisa Asylum software (mask ine range ye100 nm uye threshold ye100 pm).
Bvisai jira resampuro moisa pamusoro pemica padaro re 2.0 cm kubva pa counter electrode kwenguva yeavhareji ye 120 s kudzivirira kubatana kwezvikamu uye kuumbwa kwemadonhwe asina kurongeka pamusoro pemica. EWNS yakaiswa zvakananga panzvimbo dzemica dzakachekwa (Ted Pella, Redding, CA). Mushure mekusvipa, pamusoro pemica wakatariswa uchishandisa AFM. Kona yekubatana pamusoro pemica yakachekwa isina kugadziriswa iri pedyo ne 0°, saka EWNS inopararira pamusoro pemica muchimiro chedomed shape20. Dhayamita (a) nekukwirira (h) kwemadonhwe anopararira zvakayerwa zvakananga kubva kuAFM topography uye zvakashandiswa kuverenga domed diffusion volume EWNS uchishandisa nzira yedu yatakambo simbisa8. Tichifunga kuti EVNS iri mubhodhi ine vhoriyamu yakafanana, dhayamita yakaenzana inogona kuverengerwa kubva ku equation (2):
Zvichienderana nenzira yatakagadzira kare, electron spin resonance (ESR) spin trap yakashandiswa kuona kuvapo kweradical intermediates yenguva pfupi muEWNS. MaAerosols akapfuudzwa nemushonga une 235 mM DEPMPO (5-(diethoxyphosphoryl)-5-methyl-1-pyrroline-N-oxide) (Oxis International Inc., Portland, Oregon). Kuyerwa kwese kweEPR kwakaitwa uchishandisa Bruker EMX spectrometer (Bruker Instruments Inc. Billerica, MA, USA) uye flat cell arrays. Acquisit software (Bruker Instruments Inc. Billerica, MA, USA) yakashandiswa kuunganidza nekuongorora data. Kutsanangurwa kweROS kwakaitwa chete kune seti yemamiriro ekushanda [-6.5 kV, 4.0 cm]. Kuwanda kweEWNS kwakayerwa uchishandisa SMPS mushure mekufunga nezvekurasikirwa kweEWNS mu impactor.
Mazinga eOzone akaongororwa uchishandisa 205 Dual Beam Ozone Monitor™ (2B Technologies, Boulder, Co)8,9,10.
Pazvinhu zvese zveEWNS, chiyero chekuyera ndicho chiyero chepakati pezviyero, uye chikanganiso chekuyera ndicho chiyero chechiyero chekutsauka. T-test yakaitwa kuenzanisa kukosha kwechimiro cheEWNS chakagadziriswa nechiyero chinoenderana nebase EWNS.
Mufananidzo 2c unoratidza Electrostatic Precipitation Pass Through System (EPES) yakagadzirwa kare uye ine hunhu hwayo inogona kushandiswa kunanga EWNS11 kunzvimbo dziri pamusoro. EPES inoshandisa EWNS charge pamwe chete nesimba remagetsi rakasimba kuti "inongedze" zvakananga pamusoro pechinhu chiri kutsvagwa. Ruzivo rweEPES system rwunoratidzwa muchinyorwa chakabudiswa munguva pfupi yapfuura naPyrgiotakis et al.11. Saka, EPES ine kamuri rePVC rakadhindwa re3D rine magumo akatetepa ane simbi mbiri dzakafanana (304 stainless steel, mirror polished) simbi dziri pakati pe15.24 cm. Mabhodhi akabatanidzwa kune sosi yekunze ine voltage yakakwira (Bertran 205B-10R, Spellman, Hauppauge, NY), bhodhi repasi raigara rakanaka uye bhodhi repamusoro raigara rakatsikwa (richiyangarara). Madziro ekamuri akafukidzwa nealuminium foil, iyo yakatsikwa nemagetsi kudzivirira kurasikirwa kwezvikamu. Kamuri ine gonhi rekumberi rakavharirwa rinobvumira nzvimbo dzekuyedza kuiswa pamapurasitiki, richisimudzwa kubva pasi pesimbi kuti dzisapindire voltage yakakwira.
Kushanda zvakanaka kweEWNS muEPES kwakaverengerwa zvichienderana neprotocol yakagadzirwa kare yakatsanangurwa muSupplementary Figure S111.
Sekamuri yekudzora, kuyerera kwechipiri kuburikidza nekamuri yecylindrical kwakabatana zvakatevedzana nehurongwa hweEPES uchishandisa firita yepakati yeHEPA kubvisa EWNS. Sezvakaratidzwa pamufananidzo 2c, aerosol yeEWNS yakapombwa nemakamuri maviri akabatana akatevedzana. Sefa iri pakati pekamuri yekudzora neEPES inobvisa chero EWNS yasara zvichikonzera tembiricha yakafanana (T), hunyoro (RH) uye ozone levels.
Utachiona hunokosha hunowanikwa muzvikafu hwakawanikwa huchisvibisa zvirimwa zvitsva zvakaita seEscherichia coli (ATCC #27325), chiratidzo chetsvina, Salmonella enterica (ATCC #53647), chirwere chinowanikwa muzvikafu, Listeria innocua (ATCC #33090), imwe nzira yeListeria monocytogenes. , Saccharomyces cerevisiae (ATCC #4098) seimwe nzira yekubikisa mbiriso, uye Mycobacterium parafortuitous (ATCC #19686) sebhakitiriya mhenyu rinodzivirira zvakanyanya zvakatengwa kubva kuATCC (Manassas, Virginia).
Tenga mabhokisi emadomasi emazambiringa asina kugadzirwa kubva kumusika wemunharaunda yako woaisa mufiriji pa4°C kusvika ashandiswa (kusvika mazuva matatu). Sarudza madomasi ekuyedza nehukuru humwe chete, hunosvika 1/2 inch mudhayamita.
Maitiro ekuisa madomasi mudumbu, kubaya, kupararira kwechirwere uye kuverenga koloni akatsanangurwa mumabhuku edu ekare uye akatsanangurwa zvakadzama muSupplementary Data 11. Kushanda kweEWNS kwakaongororwa nekuisa madomasi akapinzwa mudumbu kusvika pa40,000 #/cm3 kwemaminitsi makumi mana nemashanu. Muchidimbu, panguva t = 0 min, madomasi matatu akashandiswa kuongorora tupukanana twakasara. Madomasi matatu akaiswa muEPES ndokuiswa muEWNS pa40,000 #/cc (madomasi akapinzwa mudumbu eEWNS) uye mamwe matatu akaiswa mukamuri rekudzora (madomasi ekudzora). Hapana kana rimwe remapoka emadomasi rakagadziriswazve. Madomasi akapinzwa mudumbu eEWNS akabviswa mushure memaminitsi makumi mana nemashanu kuti vaongorore kushanda kweEWNS.
Kuedza kwega kwega kwakaitwa katatu. Kuongororwa kwedata kwakaitwa zvichienderana neprotocol yakatsanangurwa muSupplementary Data.
Masampuli emabhakitiriya eE. coli, Enterobacter, uye L. innocua akaoneswa kuEWNS (45 min, EWNS aerosol concentration 40,000 #/cm3) uye asina kusvibiswa akachekwa kuti aone mashandiro ekuita kuti mvura isashande. Mvura yacho yakagadziriswa kwemaawa maviri patembiricha yemumba mu 0.1 M sodium cacodylate solution (pH 7.4) ne fixative ye 2.5% glutaraldehyde, 1.25% paraformaldehyde uye 0.03% picric acid. Mushure mekushambidzwa, akagadziriswa ne 1% osmium tetroxide (OsO4)/1.5% potassium ferrocyanide (KFeCN6) kwemaawa maviri, akagezwa katatu nemvura uye akachengetwa mu 1% uranyl acetate kweawa imwe, ndokuzogezwa kaviri nemvura. Kupera kwemvura mumuviri kunotevera kwemaminitsi gumi e50%, 70%, 90%, 100% alcohol. Masampuleti acho akaiswa mupropylene oxide kweawa imwe chete ndokuiswa mumusanganiswa we1:1 wepropylene oxide neTAAP Epon (Marivac Canada Inc. St. Laurent, CA). Masampuleti akaiswa muTAAB Epon ndokuiswa polymer pa60°C kwemaawa makumi mana nemasere. Resin yakachekwa yakachekwa uye yakatariswa neTEM uchishandisa JEOL 1200EX (JEOL, Tokyo, Japan), microscope yemagetsi inotumirwa ine kamera yeAMT 2k CCD (Advanced Microscopy Techniques, Corp., Woburn, MA, USA).
Kuedza kwese kwakaitwa katatu. Panguva yega yega, kushambidzwa kwemabhakitiriya kwakapetwa katatu, zvichikonzera huwandu hwemapoinzi mapfumbamwe papoinzi imwe neimwe, avhareji yacho yakashandiswa sehuwandu hwemabhakitiriya echinhu ichocho. Kutsauka kwakajairwa kwakashandiswa sekukanganisa kwekuyera. Mapoinzi ese anoverengwa.
Kuderera kwehuwandu hwebhakitiriya muhuwandu hwe t = 0 min kwakaverengerwa uchishandisa fomura inotevera:
apo C0 ihuwandu hwebhakitiriya mumuenzaniso wekudzora panguva 0 (kureva mushure mekunge pamusoro paoma asi usati waiswa mukamuri) uye Cn ihuwandu hwebhakitiriya pamusoro mushure memaminitsi n ekusangana.
Kuti tinzwisise kuparara kwemabhakitiriya kwechisikigo mukati memaminitsi makumi mana nemashanu ekushandiswa, Log-Reduction yakaverengerwawo zvichienzaniswa nekudzora pamaminitsi makumi mana nemashanu seizvi:
Apo Cn iri huwandu hwebhakitiriya mumuenzaniso wekudzora panguva n uye Cn-Control iri huwandu hwebhakitiriya rekudzora panguva n. Data rinoratidzwa sekudzikira kwelog zvichienzaniswa nekudzora (hapana kusangana neEWNS).
Munguva yekudzidza, kusanganiswa kwakati wandei kwevoltage uye daro pakati petsono ne counter electrode kwakaongororwa maererano nekuumbwa kweTaylor cone, kugadzikana kweTaylor cone, kugadzikana kwekugadzirwa kweEWNS, uye kudzokororwa. Kusanganiswa kwakasiyana-siyana kunoratidzwa muSupplementary Table S1. Zviitiko zviviri zvakasarudzwa kuti zviongororwe zvizere zvichiratidza hunhu hwakagadzikana uye hunodzokororwa (Taylor cone, kugadzirwa kweEWNS, uye kugadzikana nekufamba kwenguva). Pamufananidzo 3 inoratidza mhedzisiro pachaji, saizi uye zviri mukati meROS yezviitiko zviviri. Mhedzisiro yacho yakapfupikiswawo muTafura 1. Kuti zviongororwe, Mufananidzo 3 neTafura 1 zvinosanganisira hunhu hweEWNS8, 9, 10, 11 yakambogadzirwa isina kugadziriswa (baseline-EWNS). Kuverengera kukosha kwestatistical uchishandisa two-tailed t-test kwakaburitswazve muSupplementary Table S2. Pamusoro pezvo, data rekuwedzera rinosanganisira zvidzidzo pamusoro pemhedzisiro yecounter electrode sampling hole diameter (D) uye daro riri pakati pe ground electrode nemuromo wetsono (L) (Supplementary Figures S2 neS3).
(a–c) Kugoverwa kwehukuru hweAFM. (d–f) Hunhu hwechaji yepamusoro. (g) Kutsanangurwa kweROS neESR.
Zvakakoshawo kuziva kuti pamamiriro ese ari pamusoro apa, ma ionization currents akayerwa aive pakati pe 2-6 µA, uye ma voltage aive pakati pe -3.8 kusvika -6.5 kV, zvichikonzera kushandiswa kwesimba kweiyi single-terminal EWNS iri pasi pe 50 mW. . generation module. Kunyangwe EWNS yakagadzirwa pasi pekumanikidzwa kwakanyanya, mazinga e ozone aive akaderera zvikuru, asingambopfuuri 60 ppb.
Mufananidzo Wekuwedzera S4 unoratidza minda yemagetsi yakaedzwa ye [-6.5 kV, 4.0 cm] uye [-3.8 kV, 0.5 cm] zvichiteerana. Minda zvichienderana nezviitiko [-6.5 kV, 4.0 cm] uye [-3.8 kV, 0.5 cm] inoverengerwa se 2 × 105 V/m uye 4.7 × 105 V/m, zvichiteerana. Izvi zvinotarisirwa, sezvo chiyero chevoltage nedaro chakakwira zvakanyanya muchiitiko chechipiri.
Pamufananidzo 3a, b panoratidza dhayamita yeEWNS yakayerwa neAFM8. Avhareji yedhayamita yeEWNS ye [-6.5 kV, 4.0 cm] uye [-3.8 kV, 0.5 cm] yakaverengerwa se27 nm uye 19 nm, zvichiteerana. Kutsauka kwegeometric standard kwekugoverwa kwezviitiko [-6.5 kV, 4.0 cm] uye [-3.8 kV, 0.5 cm] i1.41 ne1.45, zvichiteerana, zvichiratidza kugoverwa kwehukuru hwakatetepa. Kutsauka kwepakati nepakati uye kutsauka kwegeometric standard zviri pedyo zvikuru nebaseline-EWNS, zviri 25 nm ne1.41, zvichiteerana. Pamufananidzo 3c panoratidza kugoverwa kwehukuru hwebaseline EWNS yakayerwa uchishandisa nzira imwechete pasi pemamiriro akafanana.
Pamufananidzo 3d,e inoratidza mhedzisiro yekutsanangurwa kwechaji. Data iri zviyero zvepakati pe30 zvekuyerwa panguva imwe chete kwehuwandu (#/cm3) uye current (I). Ongororo iyi inoratidza kuti avhareji yekuchaja paEWNS i22 ± 6 e- uye 44 ± 6 e- ye [-6.5 kV, 4.0 cm] uye [-3.8 kV, 0.5 cm], zvichiteerana. Zvichienzaniswa neBaseline-EWNS (10 ± 2 e-), chaji yavo yepamusoro yakakwira zvakanyanya, kaviri pane [-6.5 kV, 4.0 cm] uye kane kana pane [-3 .8 kV, 0.5 cm]. 3f inoratidza data rekutanga rekubhadhara reEWNS.
Kubva pamamepu ehuwandu hweEWNS (Zvifananidzo Zvekuwedzera S5 neS6), zvinogona kuonekwa kuti nzvimbo ye [-6.5 kV, 4.0 cm] ine huwandu hwakawanda hwezvimedu kupfuura nzvimbo ye [-3.8 kV, 0.5 cm]. Zvinofanirawo kucherechedzwa kuti huwandu hwehuwandu hweEWNS hwakatariswa kwemaawa anosvika mana (Zvifananidzo Zvekuwedzera S5 neS6), uko kugadzikana kwechizvarwa cheEWNS kwakaratidza mazinga akafanana ehuwandu hwezvimedu muzviitiko zvese zviri zviviri.
Mufananidzo 3g unoratidza EPR spectrum mushure mekudzora (background) kubvisa EWNS yakagadziriswa pa [-6.5 kV, 4.0 cm]. ROS spectrum inoenzaniswawo neEWNS baseline mupepa rakamboburitswa. Huwandu hwakaverengerwa hweEWNS ichiita ne spin trap i7.5 × 104 EWNS/s, iyo yakafanana neBaseline-EWNS8 yakamboburitswa. EPR spectra yakaratidza zvakajeka kuvapo kwemarudzi maviri eROS, uko O2- yainyanya, nepo OH• yaivepo muhuwandu hushoma. Pamusoro pezvo, kuenzanisa zvakananga kwe peak intensities kwakaratidza kuti EWNS yakagadziriswa yaive neROS yakawanda zvakanyanya kana ichienzaniswa neEWNS yekutanga.
Pamufananidzo 4 panoratidza kushanda zvakanaka kweEWNS muEPES. Data iri rakapfupikiswawo muTable I uye richienzaniswa nedata rekutanga reEWNS. Kune ese ari maviri maEUNS, kuiswa kwacho kwaive pedyo ne100% kunyangwe paine voltage yakaderera ye3.0 kV. Kazhinji, 3.0 kV yakakwana kuwana 100% yekuisa zvinhu zvisinei nekuchinja kwechaja yepamusoro. Pasi pemamiriro akafanana, kushanda zvakanaka kweBaseline-EWNS kwaive 56% chete nekuda kwechaja yakaderera (avhareji maerekitironi gumi paEWNS imwe neimwe).
Mufananidzo 5 neTafura 2 zvinopfupikisa mwero wekurega kushanda kwetupukanana twakaiswa pamusoro pematomatisi mushure mekusangana ne40,000 #/cm3 EWNS kwemaminitsi makumi mana nemashanu pasi pemamiriro akanaka [-6.5 kV, 4.0 cm]. E. coli neL. innocua zvakaiswa zvakaratidza kudzikira kukuru kwe3.8 log mushure memaminitsi makumi mana nemashanu ekusangana. Pasi pemamiriro akafanana, S. enterica yakaratidza kudzikira kwakaderera kwe2.2 log, nepo S. cerevisiae neM. parafortuitum zvakaratidza kudzikira kwe1.0 log.
Maelektroni micrographs (Mufananidzo 6) anoratidza shanduko dzemuviri dzinokonzereswa neEWNS mumasero eE. coli, Salmonella enterica, uye L. innocua zvichikonzera kusashanda. Mabhakitiriya ekudzora akaratidza membrane dzemasero dzisina kukuvadzwa, nepo mabhakitiriya akafumurwa akakuvadza membrane dzekunze.
Kutorwa kwemaelektroni nemaikorosikopu kwemifananidzo yekudzora uye mabhakitiriya akaonekwa pachena kwakaratidza kukuvara kwemembrane.
Ruzivo pamusoro pehunhu hwefizikisi hweEWNS dzakagadziriswa pamwe chete runoratidza kuti hunhu hweEWNS (surface charge uye ROS content) hwakavandudzwa zvakanyanya zvichienzaniswa nedata rekutanga reEWNS rakabudiswa kare8,9,10,11. Kune rumwe rutivi, saizi yavo yakaramba iri mu nanometer range, iyo yakafanana zvikuru nemhedzisiro yakamboburitswa kare, zvichivabvumira kugara mumhepo kwenguva yakareba. Kupararira kwakaonekwa kunogona kutsanangurwa nekuchinja kwe surface charge, iyo inosarudza hukuru hweRayleigh effect, randomness, uye kubatanidzwa kweEWNS. Zvisinei, sezvakatsanangurwa naNielsen et al.22, high surface charge inoderedza evaporation nekuwedzera zvinobudirira simba repamusoro/kumanikidzwa kwedonhwe remvura. Iyi dzidziso yakasimbiswa nekuyedza kune microdroplets22 neEWNS muchinyorwa chedu chekare8. Kurasikirwa nenguva yekuwedzera kunogonawo kukanganisa saizi uye kubatsira mukugoverwa kwehukuru kwakacherechedzwa.
Pamusoro pezvo, muripo pachivako chimwe nechimwe ungangoita 22–44 e-, zvichienderana nemamiriro ezvinhu, izvo zvakakwirira zvakanyanya kana tichienzanisa neEWNS yekutanga, ine avhareji yekuchaja ye10 ± 2 maerekitironi pachivako chimwe nechimwe. Zvisinei, zvinofanira kucherechedzwa kuti iyi ndiyo avhareji yekuchaja yeEWNS. Seto et al. Zvakaratidzwa kuti muripo hauna kufanana uye unotevera kugoverwa kwakajairika kwelog-normal21. Zvichienzaniswa nebasa redu rekare, kupeta kaviri muripo wepamusoro kunowedzera kaviri kushanda kwekuisa muEPES system kusvika pa100%11.