The Antibacterial and Antifungal Textile Properties Functionalized by Bimetallic Nanoparticles of

14 Pages·2016·5.65 MB·English

Hindawi Publishing Corporation
Journal of Nanomaterials
Volume 2016, Article ID 6056980, 13 pages
http://dx.doi.org/10.1155/2016/6056980
Research Article
The Antibacterial and Antifungal Textile Properties
Functionalized by Bimetallic Nanoparticles of Ag/Cu with
Different Structures
MartaPaszkiewicz,1AnnaGoBdbiewska,2AukaszRajski,3EwelinaKowal,3
AgnieszkaSajdak,3andAdrianaZaleska-Medynska1
1DepartmentofEnvironmentalTechnology,FacultyofChemistry,UniversityofGdansk,80-308Gdansk,Poland
2DepartmentofChemicalTechnology,FacultyofChemistry,GdanskUniversityofTechnology,80-233Gdansk,Poland
3LaundryandDryCleaningCenter,Eko-StylRentalSp.zo.o.Sp.k.,37-300Lezajsk,Poland
CorrespondenceshouldbeaddressedtoAnnaGołąbiewska;[email protected]
Received8February2016;Accepted4April2016
AcademicEditor:R.Torrecillas
Copyright©2016MartaPaszkiewiczetal. This is an open access article distributed under the Creative Commons Attribution
License,whichpermitsunrestricteduse,distribution,andreproductioninanymedium,providedtheoriginalworkisproperly
cited.
Wereportedapreparationandcharacterizationoffivekindsofimpregnationsolutions,containingAg/Cuintheformofbimetallic
nanoparticles(alloyandcore-shell)aswellasionicspecies.Thecotton-polyestertextilesweresuccessfullyimpregnatedduring
thewashingandironingprocessbyas-preparedsolutionstohaveantibacterialandantifungalpropertiesagainsttoEscherichia
coli,Staphylococcusaureus,andCandidaalbicans.Moreover,wehavereportedtheeffectoftypeofthefabricusedandnumber
ofwashing/impregnationcycles(inalaboratoryscale)onthebactericidalandfungicidalactivityofobtainedtextiles.Theresults
indicatedthatalltestedsamplesafter5,10,15,and20washing/impregnatedcyclesexhibitedanantimicrobialactivity.Theantifungal
+ 2+ 2+
testsshowedthatonlytextileimpregnatedwithsolutionscontainingAg /Cu andAgNPs/Cu exhibitedastronginhibitionof
fungigrowthoftheafter5(99.99%)and15(100%)washing/impregnationcycles,respectively.
1.Introduction On the other hand, cotton, wool, and synthetic textiles
containingmetalnanoparticles,suchassilver[7–9]orcooper
Textiles are excellent substrates for a bacterial growth and
[10–12],inordertoimpartantimicrobialpropertiesareused
microbial proliferation under appropriate moisture, nutri-
ascommercialbiomedicalproducts.Thenanoparticles,even
ents, and temperature conditions. In the hospital environ-
inverysmallamounts,canprovidethefinalproductwithbac-
ment, polluted textiles can be an important source of bac-
teriostaticpropertiesduetothefactthatnanoscaledmaterials
teria,viruses,andfungithatmayprimarilycontaminatethe
haveahighratioofasurfaceareatovolume[13].Silverinits
patientsandclinicianpersonnel.Additionally,thecontami-
metallicstateisinertbutitreactswiththemoistureandgets
nationoftextilesintheclinicalsettingsmaycontributetothe
toionize.Theionizedsilverishighlyreactive,asitbindsto
dispersal of pathogens to the air, which then fall down and
tissueproteinsandbringsstructuralchangesinthebacterial
infecttheimmediateandnonimmediateenvironment.Thus,
cellwallandnuclearmembraneleadingtocelldistortionand
transferofmicroorganismsfromthecontaminatedsurfaceto
thesusceptiblepatientsisoneofthemostcommonreasons death. Silver nanoparticles also bind to bacterial DNA and
of nosocomial infections (hospital-acquired infections) [1]. RNA by denaturing and inhibiting bacterial replication [14,
Themostcommonpathogenmicroorganismsresponsiblefor 15].Ontheotherhand,coppernanoparticles,suchasCuand
nosocomialinfectionsincludeEscherichiacoli,Pseudomonas CuO,exhibitahighantimicrobialactivityagainstwidespec-
aeruginosa,Staphylococcusaureus,Legionella,andMycobac- trumofmicroorganisms,includingfungiandGram-positive
teriumtuberculosis[2–6]. andGram-negativebacteria[16].Accordingtotheliterature,
2 JournalofNanomaterials
themechanismofantibacterialactivityofcopperNPsisgene- antibacterial and antifungal properties, could be used for
rallybasedonmetallicions[17–20]. production of bed linen and work wear used in medical
Itwasfoundthattheantimicrobialpropertiesofsilverand facilities,nursinghomes,andhotels.
coppernanoparticlesaredependentonthesizeandshapeof
particles,whichresultedfromthepreparationroute[21,22].
2.MaterialsandMethod
Generally, monodisperse nanoparticles composed of silver
andcoppercouldbeobtainedbychemicalreduction[23–29], 2.1.MaterialsandInstruments. Copperacetatereceivedfrom
electrochemical [30–35], photochemical [36–41], and sono- AvantorPerformanceMaterialsPolandS.A.wasusedasthe
chemicalmethods[42–45]aswellasusingpulsedlaserdepo- precursorforthepreparationofsamples.Silvercitratewasas-
sition[46–51].Amongallthesemethods,chemicalreduction preparedaccordingtotheproceduregiveninSupplementary
inaqueoussolutionisstilloneofthemostcommonlyused materials (see Supplementary Material available online at
methodsdueto(i)lowcostofrawmaterialsandequipment, http://dx.doi.org/10.1155/2016/6056980).Reagentsneededto
(ii)lowprocesstemperature,(iii)simplicity,(iv)tightcontrol synthesizesilvercitratesuchassodiumcitrate(III)andsilver
of size, shape, and stricture of NPs, and (v) possibility of carbonate were provided by Sigma-Aldrich and citric acid,
deposition of nanoparticleson different substrates to create sodiumhydroxide,andaceticacidwerereceivedfromAvan-
new features (such as antimicrobial properties). Cabal et torPerformanceMaterialsPolandS.A.Sodiumborohydride
al. [52] obtained silver NPs immobilized on kaolin crystal 99% was provided by Aldrich and used as the reducing
usingthermalandchemicalreduction.Theyfoundthatsilver agent.Polyvinylpyrrolidone(PVP)wasreceivedfromSigma-
NPsrevealedahighantimicrobialactivityagainstEscherichia Aldrich and was used as the stabilizers. Isopropanol and
coli JM 110 and Micrococcus luteus bacteria. Sua´rez et al. distilled water were used as the reaction media. All the
[53] synthesized diatom containing metallic silver NPs by chemicalswereusedwithoutthefurtherpurification.
chemical reduction method. The diatom-silver nanocom-
Thetextilesusedinthetestswerecommerciallyavailable:
posite has proved to be a selective green inorganic biocide
Malwa150-OpticalWhite,barriertextileESD150-gray(Pro-
whichreducesthestartingconcentrationsofEscherichiacoli
ducer:ANDROPOLS.A.,Poland).
andMicrococcusluteus.Diatom-nAgcanbeconsideredasa
Prewash has been carried out with used Turbo Break
selectiveinorganicbiocideparticularlysuitableforthefood
(Detergent 1), (NaOH 25–30%), Silex Emulsion (Detergent
andpharmacologicalsectors.
2) (fatty alcoholethoxylates 10–20%,NaOH 10–20%); main
The antimicrobial and antifungal properties of textiles
wash has been made with used Turbo Break (Detergent
modified with monometallic nanoparticles such as copper
1), Silex Emulsion (Detergent 2), and Ozonit Performance
[10,54–58]andsilver[7,8,54]arewellestablished.However,
(Detergent 3) (acetic acid 25–30%, hydrogen peroxide 10–
onlylimiteddataonthepossibleantimicrobialandantifungal
20%, peracetic acid 10–20%) and rinsed with used Finale
activity of textiles modified by combination of silver and
Liquid(Detergent4)(formicacid10–90%).Detergentsused
copperintheformofbimetallicnanoparticlesaswellasionic
inwashingcyclescamefromtheEcolabSp.Zo.o.company
speciesareavailable[59].Moreover,althoughthepreparation
(Poland).
methods of bimetallic nanoparticles of Ag/Cu are well-
ThediffusereflectanceUV-Visabsorptionspectraofthe
described in the literature [60–65], then the antimicrobial
samples were obtained using a spectrophotometer UV-Vis
properties of those particles were mentioned in only a few
Thermo model: Nicolet Evolution 220. TEM analysis was
papers[66–68].Additionally,oneofthescientificchallenges
performed on the FEI Tecnai F20 X-Twin microscope with
is how to produce antimicrobial textiles in easy and cheap
thespectrometerEDX(r-TEMSUTW,EDAX).Thesamples
way to apply them in facilities with a high risk of infection
were observed under bright-field (BF STEM) and SE mode
bypathogens(mainlyhospitalsfacilities).
(detection of secondary electrons, information about the
In view of this, we recently obtained and characterized
morphology of the surface). Samples were suspended in
aseriesofcolloidalsolutionstoimpregnatefabricsthatwill
ethanol(99.8%)andwereputintoanultrasonicbath(Inter-
exhibit antibacterial and antifungal properties [69]. In this Sonic IS-1K) for 5 seconds. Then, the drop (4𝜇L) was col-
workweshowtheapplicationofselectedfivetypesofimpreg-
lectedandplacedonacoppermeshcoatedwithacarbonlayer
nationsolutions,containingAg/Cuintheformofbimetallic
with holes (Plano, type Lacey Cu 400 mesh). The solvent
nanoparticles (alloy and core-shell) as well as ionic species,
wasevaporatedatroomtemperature.Themorphologyofthe
fortextilesimpregnation.Forthefirsttime,thecomposition
textileswasinvestigatedwithscanningelectronmicroscope
ofAg/Cu-basedsolutionsinrelationtotheirantibacterialand
(SEM) using LEO Electron Microscopy Ltd., model 1430
antifungalpropertiesaswellastheirabilitytofunctionalize
VP (2001) equipped with X-ray spectrometer, Quantax 200
thesurfaceoftextileduringwashingandironingprocesshas
detector XFlash 4010 production of Bruker AXS, Germany
been investigated[70]. Antibacterialand antifungalactivity
(2008), and tungsten cathode, accelerating voltage from
wastestedagainstEscherichiacoli,Staphylococcusaureus,and 200Vto30kV.Thetextilesizesamplesof1.3×1.3cmwere
Candida albicans, respectively. The effect of impregnation
blowingwithinertgasinordertoremovesurfacecontami-
0 +
solution composition (Ag/Cu(alloy), AgcoreCushell, Cu /Ag , nation.Thenthesamplewasattachedtothemicroscopestage
0 2+ + 2+
Ag /Cu , and Ag /Cu ) and the type of textile on the withdoublesideddiscsofcoal.Thecarboncontainedinthe
antimicrobial features of the impregnated textile were sys- discs creates a conductive layer providing discharge static
tematicallyinvestigated.Thefunctionalizedtextiles,showing electricityofthesamples.
JournalofNanomaterials 3
Table1:Propertiesoftextilesusedforimpregnation.
Composition Specific Fiber Numberof
surfacearea diameter filamentsper
Textileslabel Fabrictype Color Polyester Cotton
(g/m2) (𝜇m) 1dm
(%) (%)
Malwa150-Optical Usual White 50 50 150 ∼7.5 296±6
White
BarriertextileESD Barrier Grey 44 54.6 125 ∼13 320±6
150-gray
2.2. Preparation of Solutions for Textile Impregnation. To effective,thebacteriostaticactivityvalueshouldbecalculated
obtainbimetallicnanoparticles,50ppmofsilvercitrateand inaccordancewiththeequation
50ppm of copper acetate as a metal precursors, water- 𝑆=𝑀𝑏−𝑀𝑐 (2)
isopropanolsolutionwithvolumeratio3:1asasolvent,and
PVP(tenfoldexcessrelativetotheprecursor)asastabilizer andthebactericidalactivityaccordingto
and NaBH4 (twofold excess relative to the precursor) as 𝐿=𝑀𝑎−𝑀𝑐, (3)
a reducing agent were used. Depending on the route of
where 𝐹 is the growth value and 𝑆 and 𝐿 are the bacte-
synthesis, various types of bimetallic nanoparticles have
riostaticand bactericidal activityvalues, respectively. 𝑀𝑎 is
been achieved. In order to obtain Ag/Cu alloy single-step
the average of common logarithm of the number of living
reductionandtoobtainthecore-shellnanoparticlesadouble-
+ 2+ bacteria on the test pieces immediately after inoculation of
step reduction has been used. Ionic solutions (Ag , Cu )
inoculumonstandardcloth.𝑀𝑏istheaverageofcommon
havealsobeenreceivedwithoutreduction.
logarithmofthenumberoflivingbacteriaonthetestpieces
after18hincubation.𝑀𝑐istheaverageofcommonlogarithm
2.3.AntibacterialandAntifungalActivityMeasurements. The
of the number of living bacteria on the test pieces after
JISL1902:2002absorptionmethodisdesignedtoquantita-
18hincubationonantibacterialtreatedsample.Traditionally,
tively test the ability of textiles that have been treated with
bacteriostaticmeanspreventionofmultiplicationofbacteria
this antibacterial agent to prevent a bacterial growth and
without destroying them, whereas the bactericidal effect
to kill bacteria, for over an 18-hour period of contact. This
impliesforthrightkillingoftheorganisms[71].
method is based on the quantitative determination of the
potential effect and activity of functionalized samples, by
2.4. Washing and Impregnation Procedures. The washing
the direct contact with a suspension of bacterial cells. For
each prepared strain of 1.0 ± 0.3 × 105cells/mL inoculum cycleinthelaboratoryscalereflectedthecycleconditionsin
thetechnologicalscale.Thetestswerecarriedoutontextiles
using nutrient broth was diluted with water of 1:20 (v:v). with10×10cmsize.Thepropertiesoffabricsusedforimpreg-
Samplesoffabricscontrolledandtreatedwithantimicrobial
nationwithAg/CuparticlesareshowninTable1.Thewashing
substances 15 × 15mm have been sterilized UV and next
cycleconsistedofthreestages:prewashatthetemperatureof
placed in sterile tubes and inoculated with an inoculum 38∘Cvia5min,mainwashat60∘Cvia5min,andrinseat45∘C
volume of 0.2mL. The samples were incubated for 18h at via5minmanuallyintheseparateflasks.Theamountofwater
∘ ∘
37 C (bacteria) and 30 C (fungi). For each strain used for used and the type of detergent determined in accordance
the control samples after 0 time as well as control and test withtheguidelinesofthecompanyEKO-STYLRentalSp.Z
samples after 18h of incubation cultures were performed o.o Sp.k [70]. Each stage of washing was carried out using
to determine the number of microorganisms: to each tube the ultrasounds (washing simulation). Then the fabric was
containingthefabricsample2mLofsterilesalinecontaining impregnated with previously prepared solutions containing
0.2% Tween 80 was added. The contents thoroughly were Ag/Cu nanoparticles. It was the postgrafting method. The
∘
mixedonthevorteksandhavedoneserialdilutionsinsterile samplesweretreatedwithhotairandnextpressedat200 C
saline.Fromthemixturebaselineandserialdilution1mLwas forabout1mintofixtheparticleswiththebindersystemon
taken.Next,theseedswereperformedonbloodagarnutrient the fabric. The process of washing and impregnation route
byfloodmethod.After48hofincubationat37∘C(bacteria) isshowninFigure1S(supportingmaterials).Theprocedure
and30∘C(fungi)thecellshavebeencounted.Inordertocarry was repeated 5 times or 20 times depending on the textiles
outthejudgmentoftesteffectiveness,thegrowthvaluewas antimicrobial activity. A yellow tint appears because of the
calculatedaccordingtothefollowingequation: oxidationofpartofsilverandcoppertotheoxidesAg2Oand
CuO.
𝐹=𝑀𝑏−𝑀𝑎. (1)
3.ResultsandDiscussion
When the growth value is more than 1.5, the test is judged
tobeeffective,andwhenthegrowthvalueis1.5orless,the 3.1.CharacterizationofImpregnationSolutions. Preparation
testisjudgedtobeineffective.Whenthetestisineffective, conditions,particlesize,andcoloroftheimpregnationsolu-
a retest is necessary. When the quantitative test has been tionsselectedfortheantibacterialandantifungaltestshave
4 JournalofNanomaterials
4.0 ThemorphologyofthestructurecreationofAg/CuNPs
wasstudiedusingCs-correctedSTEM(HighAngleAnnular
3.5 Dark Field, HAADF) with EDXS mapping. Therefore, it is
possible to get images in a high resolution with z-contrast
3.0 basedontheelasticscatteringoftheprimarybeamwiththe
sample.Figure2showsthemorphologyofAg/Cubimetallic
nanoparticles obtained by chemical reduction method with
2.5
correspondingparticlesizedistribution.TheaverageAg/Cu
e
nc size(𝑑Ag/Cu)wascalculatedfromthestatisticalaveragesize
Absorba 2.0 4084n1m0nm otof19000nAmg./HCuowNePvse.rRitesisunlteserdeevdeatlonbaenhoipgahrltiigchletsedratnhgaitnpgafrrtoicmles1
1.5 with diameter >50nm result from the agglomeration of
smallerparticles.ThesampleAg/Cu(alloy)isformedmainlyby
1.0
particleswithsizesrangingfrom1to30nm,withthehigher
contribution of the 1–15nm nanoparticles (Figure 2(a)).
0.5 398nm 487nm However, the Agcore/Cushell sample formed mainly particles
withdiameter1–40nm(90%),Figure2(b).
0.0 In order to investigate the properties of the individual
200 300 400 500 600 700
nanoparticles,wechoseoneparticlefromeachsample.Fig-
Wavelength (nm) ures 3(a)-3(b) show the alloy Ag/Cu spherical nanoparticle
Ag/Cu(alloy) Ag NPs/Cu2+ with diameter ∼20nm. The uniform distribution of silver
Agcore/Cushell Ag+/Cu2+ (navyblueregion)andcopper(brightblueregion)withinone
Cu NPs/Ag+ particleisobservedwhichcorrespondstothealloystructure
of obtained NPs. Moreover, the EDXS mapping confirmed
Figure1:UV-Visspectraofobtainedimpregnationsolution.
that Ag and Cu signal occurred in the same area as shown
inFigure2(b).Itwasobservedthatmetalswerewellmixedin
itscomposition.
beenshowninTable2.Differentcombinationsofsilverand ThemorphologyofAg/Cunanoparticleobtainedbytwo-
copperspeciessuspendedordilutedintheaqueoussolution step reduction is shown in Figures 4(a)-4(b). The observed
havebeenused,suchasalloyAu/Cunanoparticles,core-shell bimetallicparticlehadsphericalshapewithdiameter∼18nm.
Au/Cu nanoparticles, Ag0/Cu2+, Cu0/Ag+, and Ag+/Cu2+ EDXS analysis revealed that silver content is higher than
a copper content in the BNPs core, while the shell of
mixtures.Itwasfoundthatthecolorofsolutionscontaining
BNPsregionisricherincopper.Thestructureofbimetallic
AuandCunanoparticlesand/orionshavechangedfromlight
nanoparticlesisdependenton(1)relativestrengthsofhomo-
yellow to dark brown depending on the composition (see
andheteronuclearbonds,(2)surfaceenergiesofbulkmetals,
detailsinTable2).
and (3) standard reduction potential of both metals [74].
Figure 1 shows the UV-Vis spectra of the obtained
Based on the experimental studies the silver has the lowest
nanoparticlesinaqueoussolution.ThesphericalAgandCu 2 2
surface energy (1.25J/m ) compared to copper (1.79J/m )
NPsexhibitsingleplasmonicband,whereastheanisotropic
[75]. The metal with lower surface energy has the suscepti-
NPs show two or more bands because of quadrupole and
bilitytosegregateonthesurfaceofothermetals[76];thusit
multipole plasmon excitations [72]. The bimetallic particles couldbeexpectedthatsilvertendstosegregateinthesurface
have a strong localized surface plasmon resonance peak at layerofCuNPs.Ontheotherhand,thereductionofsilver
408nm and 410nm for the Agcore/Cushell and Ag/Cu(alloys), (𝐸𝑜 = 0.79V) and copper (𝐸𝑜 = 0.521V) potential was
respectively. Single fine band represents the formation of notsignificantlydifferent.Theabundantliteratureshowsthat
spherical nanoparticles. Taner et al. [66] suggest that dis- a large difference in the reduction potential usually results
placement of LSPR to 420nm could be attributed to the inacore-shellstructureandasmalldifferenceinreduction
formationofalloystructureofAg/CuNPs.Inthecaseofcore- potential usually leads to an alloy structure [77]. Generally,
shellstructureoftheAg/Cunanoparticlesthepositionofthe according to the theoretical and experimental studies, Ag-
absorption spectra depends on the thickness of the copper Cucompositiontendstoformcore-shellstructure.However,
shell [73]. The UV-Vis spectra also confirm the presence of basedontheTEManalysis,itcouldbestatedthatas-prepared
+ 2+
combinationofNPs(AgorCu)withions(Ag orCu ).The bimetallic nanoparticles obtained by the one-step and two-
2+
AgNPs/Cu sampleexhibitedabsorptionbandsat398nm step reduction revealed alloys and core-shell structures,
and230nm,confirmingthepresenceofsilverparticlesand respectively.
+
copperions,respectively.Ontheotherhand,theCuNPs/Ag
samplerevealedabsorptionbandat484nm,whichcouldbe 4.CharacterizationofImpregnatedTextiles
ascribed to the presence of copper nanoparticles. The most
intensive absorption band (ca. 230nm) was observed for 4.1.TheEffectofWashingCyclesontheAntibacterialandAnti-
ionicAg.Itisevidentthatforsamplescontainingonlyions fungalPropertiesoftheTextiles. Table3showsdetailsabout
ofsilverandcopperitwasobservedpeakatabout235nm. thetypeofusedmicroorganisms,theimpregnationsolutions
JournalofNanomaterials 5
Table2:Preparationrouteandcharacteristicsofbimetalliccolloids.
Particlesize Structuresof
Samplelabel Preparationroute Imageofimpregnationsolution
(nm) metal
Ag3C6H5O7,C4H6O4Cuasa Ag/
Ag/Cu(alloy) precursors,singlestepreduction ∼20nm Alloy Cu(alloy)
withNaBH4,andstabilizerPVP
Agcore/Cushell preAcgu3rCso6rHs,5Odo7u,bCl4eHst6eOp4rCeuduacstaion ∼18nm Core/shell ACgucore/
withNaBH4,andstabilizerPVP shell
Firstsolution:Ag3C6H5O7;second
solution:C4H6O4Cuasaprecursor,
CuNPs/Ag+ sstainbgilliezesrtePpVrePd;umcitxioinngwoifthprNevaiBoHus4l,y ∼N3P0snCmu NPs/ions CuA Ng+Ps/
preparedsolutions(1and2)in
volumeratio1:1
Firstsolution:C4H6O4Cu;second
solution:Ag3C6H5O7asa
2+ precursor,singlestepreduction NPsAg Ag NPs/
AgNPs/Cu withNaBH4,stabilizerPVP;mixing ∼18nm NPs/ions Cu2+
ofpreviouslypreparedsolutions(1
and2)involumeratio1:1
Ag+/Cu2+ Ag3C6H5O7,C4H6O4Cuasa — Ions/ions Ag+/
precursorsintheH2Osolution 2+
Cu
6 JournalofNanomaterials
100 100
%) %)
hare ( 6800 hare ( 6800
age s 40 age s 40
nt nt
Perce 200 Perce 200
1–15 15–30 >30 1–40 40–80 >80
Particle diameter (nm) Particle diameter (nm)
100nm 500nm
(a) (b)
Figure2:TEMimagesandparticlesizedistributionof(a)Ag/Cu(alloy)and(b)Agcore/Cushellnanoparticles.
Cu W%
Ag W%
10nm 50nm
(a) (b)
Figure3:TEMimagesofobtainedbimetallicAg/Cu(alloy)nanoparticles,(a)SEmode,and(b)pointchemicalanalysisEDX.
and the concentration of the inoculum. Experimental trials the strong bactericidal and bacteriostatic properties. The
were made on the textile Malwa 150-Optical White with antifungal tests showed that only textile impregnated with
differenttypesofimpregnationsolutionswithAg/Cumetals solutions made of Ag+/Cu2+ and Ag NPs/Cu2+ exhibited
used. The materials details are used as shown in Table 3. a strong inhibition of fungi growth after 5 (99.99%) and
Textilesamplesweretestedafter5,10,15,and20cyclesofthe 15 (100%) washing/impregnation cycles, respectively. For
washingandimpregnationprocess. the other solutions, fungal growth was observed even after
It was observed that all tested samples in the next 20 washing/impregnation cycles. The inhibition of growth
washing/impregnatedexhibitedanantimicrobialactivity. for Candida albicans, in relation to the reference sample,
In all cases the percentage of reduction in cell growth equaled 4.89%, 20.3%, and 27.23% for textile impregnated
relative to the control samples was 100%, which suggests with solutions composed of Cu NPs/Ag+, Ag/Cu(alloy), and
JournalofNanomaterials 7
Cu W%
Ag W%
5nm 20nm
(a) (b)
Figure4:TEMimagesofobtainedbimetallicAgcore/Cushellnanoparticles,(a)SEmode,and(b)pointchemicalanalysisEDX.
Agcore/Cushell, respectively. The strongest bactericidal and Accordingtotheliterature,thebimetallicnanoparticlesof
fungicidal features of the textile sample impregnated with Ag/Cu exhibited enhanced antimicrobial activity compared
+ 2+
Ag /Cu ionscouldbe attributedto theexistence ofsilver to pure elements and were associated with the synergetic
+ 2+
and copper in the form of (i) Ag and Cu ions; (ii) effect of two metals [67, 68, 82]. High antimicrobial and
nanoparticles Ag/Cu; and (iii) metal oxides (Ag2O, CuO), antimycotic properties of tissues impregnated with the low
formed in situ during the washing and ironing process due concentrationsofAgandAg/Cunanoparticles(intherange
+ 2+
to the chemical reaction between Ag and Cu ions with 0.06–0.25wt% for Ag and 0.015–0.13wt% for Ag/Cu) were
washingchemicalsandunderhightemperature(38,60,45, confirmedintheexperimentswithawiderangeofbacteria
∘
and 200 C for washing, rinsing, and ironing, resp.). The and fungi: Escherichia coli, Enterobacter aerogenes, Proteus
+ 0
coexistenceofsilverandcopperinthethreeforms(Ag ,Ag , mirabilis,Klebsiellapneumoniae,Candidaalbicansyeasts,and
2+ 0
andAg2OandCu ,Cu ,andCuO)couldenhancemicrobial micromycetes.TextilematerialswithAgNPsdemonstrateda
activityofimpregnatedtextiles.Moronesetal.[78]observed highantibacterialactivity,whilefabricsdopedwithbimetallic
that silver nanoparticles adhere to the surface of the cell
Ag/Cuhadpronouncedantimycoticproperties.Bactericidal
membrane of bacteria and drastically disturb its proper
and antifungal properties of the obtained materials did not
function.TheystatedthatAgNPsareabletopenetrateinside ∘
changeafterwashingandironingpressingat200–220 C[59].
thebacteriaandcausefurtherdamagebypossiblyinteracting
Geranioetal.[83]revealedthatAgintheparticulatefraction
withsulfur-andphosphorus-containingcompoundssuchas
+ >450nm is probably the predominant form of Ag released
DNA.Ag ionsalsocausecellreplicationdamagebybinding
into the washing liquor. On the one hand the release of Ag
with bacterial DNA [79]. Copper metal ions also play an
from the textiles depends on the form and the amount of
importantroleinthemechanismofaction,suppressingcell
Ag in the textiles but also on the medium that is used for
growth by inhibiting activity of DNA gyrase, an essential
bacterialenzymethatmaintainssuperhelicaltwistsinDNA washing.Additionally,thedetergentscontainbleachingagent
[80].Summarizingofthemechanismsfortheirbactericidal that rapidly oxidizes nano-Ag and results in a fast release
+
effects,thesilverorcopperionsreleasedbythenanoparticles ofdissolved Ag [9]. However, theNPs-suspension showed
may attach to the negatively charged bacterial cell wall and that the presence of different surfactants at concentrations
rupture it, thereby leading to protein denaturation and cell relevant to washing has only a small influence on the
death[68].InthiswayAgandCuNPscanbewidelyusedin oxidativedissolutionofAg(0)[83].
antimicrobialcoatingsinmedicalinstrument.Turalijaetal.
Figure 5 shows an example of the plates with fungi
[81]statedthattextilescontainingCu2Oexhibitedtheantimi- Candida albicans corresponding to the solution obtained
crobial activity. The washing processes caused decreases in
after washing inoculum from the control and test samples:
the Cu content in textiles but it still retains the antimi-
2+
textileimpregnatedwiththesolutionsAgNPs/Cu after20
crobial properties. Matyjas-Zgondek et al. [13] investigated
+
washingcycleandCuNPs/Ag after10washingcycles.Itis
the antibacterial efficiency of silver-finished textiles using
Escherichia coli and Bacillus subtilis. The authors conclude clearly visible inhibition of fungal growth on the plate with
2+
that the obtained results proved the good and long-lasting textileimpregnatedwithAgNPs/Cu (99.99%reductionin
+
bacteriostaticefficiencyofsilvernanoparticlesappliedduring cellgrowth)asopposedtoCuNPs/Ag (0%reductionincell
thefinishingofcotton. growth).
8 JournalofNanomaterials
Table3:TheeffectofwashingcyclesonthemicrobialactivityoftextileMalwa150-OpticalWhite.Thestaticactivitywasdeterminedin
accordancewiththefollowingequation:𝑆 = 𝑀𝑏−𝑀𝑐(seedetailsinSection2).Thelethalactivitywasdeterminedinaccordancewiththe
followingequation:𝐿=𝑀𝑎−𝑀𝑐(seedetailsinSection2).
Candidaalbicans Escherichiacoli Staphylococcusaureus
Bacterialstrain
ATCC10231 ATCC8739 ATCC6538
Inoculum(cell/mL) 0.9±0.3×105 1.5±0.2×105 1.3±0.2×105
Valueofgrowth(𝐹) 1.54 1.54 1.50
Typeofsolution Ag/Cu(alloy)
Numberofwashingcycles (𝑆)/(𝐿)∗ 𝑅∗∗ (𝑆)/(𝐿) 𝑅 (𝑆)/(𝐿) 𝑅
5 −0.11/−1.64 0% Absence∗∗∗ 100% Absence 100%
10 −0.02/−1.56 0% Absence 100% Absence 100%
15 −0.12/−1.66 0% Absence 100% Absence 100%
20 0.10/−1.44 20.3% Absence 100% Absence 100%
Typeofsolution Agcore/Cushell
Numberofwashingcycles (𝑆)/(𝐿) 𝑅 (𝑆)/(𝐿) 𝑅 (𝑆)/(𝐿) 𝑅
5 0.12/−1.41 25% Absence 100% Absence 100%
10 −0.04/−1.58 0% Absence 100% Absence 100%
15 −0.02/1.56 0% Absence 100% Absence 100%
20 0.14/−1.40 27.23% Absence 100% Absence 100%
2+
Typeofsolution AgNPs/Cu
Washingcycle (𝑆)/(𝐿) 𝑅 (𝑆)/(𝐿) 𝑅 (𝑆)/(𝐿) 𝑅
5 −0.04//−1.58 0% Absence 100% Absence 100%
10 0.07/−1.46 15.59% Absence 100% Absence 100%
15 4.57/2.96 100% Absence 100% Absence 100%
20 4.09/2.49 99.99% Absence 100% Absence 100%
+
Typeofsolution CuNPs/Ag
Washingcycle (𝑆)/(𝐿) 𝑅 (𝑆)/(𝐿) 𝑅 (𝑆)/(𝐿) 𝑅
5 −0.06/−1.66 0% Absence 100% Absence 100%
10 −0.15/−1.75 0% Absence 100% Absence 100%
15 −0.05/−1.66 0% Absence 100% Absence 100%
20 0.02/−1.58 4.89% Absence 100% Absence 100%
+ 2+
Typeofsolution Ag /Cu
Numberofwashingcycles (𝑆)/(𝐿) 𝑅 (𝑆)/(𝐿) 𝑅 (𝑆)/(𝐿) 𝑅
5 4.02/2.48 99.99% Absence 100% Absence 100%
∗Theactivityofstatic(𝑆)/lethal(𝐿).∗∗The%reductionincellgrowthrelativetothecontrolsamples.
∗∗∗
Absencemeansthecompleteeliminationofmicroorganisms.Thesampleisactivemicrobiologically.
4.2. The Effect of the Type of Textiles on the Antibacterial Takai et al. [84] demonstrated that there are differences
and Antifungal Properties. To investigate the effect of the in antibacterial properties among commercially available
textiles type the two commercially available textiles were antimicrobial-finishedtextileproductscontainingAg.Addi-
used: usual fabric textile Malwa 150-Optical White and tionally, the antibacterial properties of these textiles in the
barrier textile ESD 150-gray. Barrier textiles are used in clinical setting may be of limited value. Therefore it seems
hospitals, pharmaceutical industry and electronics due to to be appropriate to apply the special barrier materials.
their impermeability for pollution particles <0.5𝜇m or a Lorenz et al. [9] reported the antibacterial activity depends
humansweat.SolutioncomposedofAg+/Cu2+(𝐶 = 50ppm onthetextileskinds,fibercompositions,andformsofsilver.
for each metals) was applied as an impregnationfactor due They stated that textiles modified with silver nanoparticles
toitsstrongestbactericidalandfungicidalproperties.Based exhibitedaveryhighantimicrobialactivityandclearlyout-
ontheexperimentalresults(showninTable4)bothtextiles performedalltheothertextiles.Manyformsofsilvercanbe
exhibitedthestrongantibacterialandantifungalproperties. appliedtotextiles,butnotallofthemshowtheantibacterial
Therefore, it could be concluded that the antibacterial and activity,whichinfactisrelatedtotherespectivereleaserates
+
antifungalpropertiesoffabricsdonotdependonthetypeof of Ag . This is especially apparent for the textile with the
fabricbutonlyonthesolutionusedfortheimpregnation. silverwire,whichhadnoantimicrobialactivity,althoughits
JournalofNanomaterials 9
+ 2+
Table4:TheeffectofthetypeoftextilesontheantibacterialandantifungalpropertieswithusesolutionofAg /Cu .Thestaticactivity
wasdeterminedinaccordancewiththefollowingequation:𝑆 = 𝑀𝑏−𝑀𝑐(seedetailsinSection2).Thelethalactivitywasdeterminedin
accordancewiththefollowingequation:𝐿=𝑀𝑎−𝑀𝑐(seedetailsinSection2).
Candidaalbicans Escherichiacoli Staphylococcusaureus
Bacterialstrain
ATCC10231 ATCC8739 ATCC6538
Inoculum(cell/mL) 1.1±0.2×105 0.9±0.2×105 1.2±0.2×105
Valueofgrowth(𝐹) 1.53 1.51 1.56
Typeoftextiles Malwa150-OpticalWhite
Washingcycle (𝑆)/(𝐿)∗ 𝑅∗∗ (𝑆)/(𝐿) 𝑅 (𝑆)/(𝐿) 𝑅
5 4,02/2,48 99.99% Absence∗∗∗ 100% Absence 100%
Typeoftextiles BarriertextileESD150-gray
Washingcycle (𝑆)/(𝐿) 𝑅 (𝑆)/(𝐿) 𝑅 (𝑆)/(𝐿) 𝑅
5 Absence 100% Absence 100% Absence 100%
∗Theactivityofstatic(𝑆)/lethal(𝐿).∗∗The%reductionincellgrowthrelativetothecontrolsamples.
∗∗∗
Absencemeansthecompleteeliminationofmicroorganisms.Thesampleisactivemicrobiologically.
Ag NPs/Cu2+ Cu NPs/Ag+
Control sample
after 20 cycles after 10 cycles
(a) (b) (c)
Figure5:Examplesoftheplatescorrespondingtothesolutionobtainedafterwashinginoculumfromthecontrolandtestsamples,Candida
albicans.
Ag content was much higher that other two nanotextiles. dominantly and uniformly distributed on textiles surface
Presumably,thesilverionreleasingsurfacewastoosmallto (Figures6(b)-6(c)).Theaveragesizeoffiberwasabout9𝜇m.
attain potent concentrations, indicating again much better Thistextilesamplewasselectedbecauseitexhibitsavery
functionalityof“nano”basedsilver-formulations[9,85]. highlevelofthebactericidalactivity.Thetextilesample,after
∘
Insummary,inourinvestigationthestrongestbacterici- impregnationwithionicsolutionwaspressedat200 C.The
+
dal and fungicidal properties were observed for the textile high temperature resulted in thermal reduction of Ag and
sample impregnated with Ag+/Cu2+. It could be caused by Cu2+ ions whereby nanoparticles of Ag/Cu were formed in
anexistenceofsilverandcopperasions,nanoparticles,and situ on the textile surface. Moreover, cotton fibers consist
oxides. Textiles modified by Ag+/Cu2+ exhibited definitely of more than 99% of cellulose containing oligosaccharides,
higher bactericidal and fungicidal properties. The effect of whichcanbeusedasareducingagent.Aldehydefunctional
groups from oligosaccharides can favor the process of sil-
ions on bacteria can be observed by the structural and
ver and copper ion reduction [59]. It was observed that
morphologicalchanges.Whentheionspenetrateinsidethe
nanoparticles diameters were in the range of 100–200nm
bacterialcelltheDNAmoleculeturnsintocondensedform
(Figure6(c)).
andlosesitsreplicationabilityleadingtocelldeath[14,86].
From the EDX analysis (Figure 7) which was used to
determine the elemental composition, it can be observed
4.3.SEM/EDXAnalysisofImpregnatedTextiles. Thescanning a uniform dispersion of Ag and Cu nanoparticles at the
electron microscopy images of the barrier textile ESD 150- surface of textile. The EDX analysis showed that the main
+ 2+
gray impregnated with the solution containing Ag /Cu components of the surface layer are carbon and oxygen. A
(𝐶=50ppm)arepresentedinthreedifferentapproximation highcontentofCandOisderivedfromcellulose.Basedon
inFigures6(a)–6(c).ItwasobservedthatAg/Cuwereformed the SEM analysis it has been shown that on the surface of
10 JournalofNanomaterials
500𝜇m 5𝜇m 2𝜇m
(a) (b) (c)
+ 2+
Figure6:SEMimagesofbarriertextileimpregnatedwithsolutionofAg /Cu ,(a)pieceoftextile,(b)onefiber,and(c)singlenanoparticles
onthefiber.
Al W% C W%
Cu W% Ti W%
O W% Ag W%
60𝜇m
+ 2+
Figure7:SEMandEDXanalysisforthebarriertextilesimpregnatedwithsolutionofAg /Cu .
+ +
barriertextilearenotonlyionsAg andCu butalsoAu/Cu aureusafter18-hincubation.Theantifungaltestsshowedthat
nanoparticleswereformedinsitumethod.Additionally,the onlythetextilesampleimpregnatedwithsolutionscontaining
textile was uniformlycoated with the solution according to Ag+/Cu2+ andAgNPs/Cu2+ exhibitedastronginhibitionof
theSEManalysis. theCandidaalbicansgrowthafter5(99.99%)and15(100%)
washing/impregnation cycles, respectively. Moreover, based
5.Conclusions ontheobtainedresultsitcouldbestatedthattheantibacterial
and antifungal properties of fabrics do not depend on the
In this work we show the application of selected five types type of fabric but mainly on the composition and dose of
of impregnation solutions, containing Ag/Cu in the form the solution used for the impregnation. The functionalized
of bimetallic nanoparticles (alloy and core-shell) as well textiles that exhibit antibacterial and antifungal properties
as ionic species, for textiles impregnation. A very strong couldbeusedforproductionofbedlinenandworkwearused
antibacterial activity and the persistent antibacterial abil- inmedicalfacilities,nursinghomes,andhotels.
ity against Escherichia coli and Staphylococcus aureus were
observed for all tested samples after 5, 10, 15, and 20 next CompetingInterests
washing/impregnation cycles. The percentage of dead cells
alreadyreached100%onEscherichiacoliandStaphylococcus Theauthorsdeclarethattheyhavenocompetinginterests.