光引发LDPE膜表面接枝聚合及高性能生物芯片的制备的中期报告【Introduction】Low-densitypolyethylene(LDPE)filmsarewidelyusedaspackagingmaterialsduetotheirexcellentmechanicalpropertiesandchemicalinertness.However,theirhydrophobicitylimitstheirapplicationsinsomefields,suchasbiosensingandbiomedicalengineering,whichrequireinteractionswithaqueoussolutions.SurfacemodificationthroughgraftpolymerizationisapromisingapproachtotailorthesurfacepropertiesofLDPEfilmsforspecificapplications.Inthiswork,weuseacombinationofUVirradiationandplasmatreatmenttoinitiatethegraftpolymerizationofacrylicacid(AA)onthesurfaceofLDPEfilms.ThemodifiedLDPEfilmsarethenusedassubstratesforthefabricationofhigh-performancebiochips.【Methods】(1)PreparationofLDPEfilmsLDPEfilms(thickness:60μm)werepurchasedfromSigma-Aldrich.Beforemodification,theLDPEfilmswerecutinto1cmx1cmsquaresandcleanedwithethanolanddeionizedwater.(2)SurfacemodificationTheLDPEfilmswerefirstirradiatedwithUVlight(λ=254nm)for30mintogenerateactivesitesontheirsurface.Then,thefilmsweretreatedwithplasmainavacuumchamberatapressureof10Pafor2mintofurtheractivatethesurface.TheactivatedLDPEfilmswereimmersedinasolutionofacrylicacid(AA,1M)andpotassiumpersulfate(KPS,10mM)for24hatroomtemperaturetoinitiatethegraftpolymerizationofAA.ThemodifiedLDPEfilmswerethenwashedwithdeionizedwatertoremoveanyunreactedreagentsanddriedundervacuum.(3)CharacterizationThesurfacemorphologyandchemicalcompositionofthemodifiedLDPEfilmswerecharacterizedbyscanningelectronmicroscopy(SEM)andFouriertransforminfraredspectroscopy(FTIR),respectively.ThegraftingdensityofAAwasdeterminedbythermogravimetricanalysis(TGA).(4)FabricationofbiochipsThemodifiedLDPEfilmswereusedassubstratesforthefabricationofbiochips.Thebiochipsconsistedofanarrayofmicroscaleelectrodesforthedetectionofbiomolecules.Theelectrodeswerefabricatedbyaphotolithographyprocessfollowedbymetaldeposition.【Results】(1)SurfacemodificationSEMimagesoftheLDPEfilmsbeforeandaftermodificationareshowninFigure1.ThesurfaceoftheunmodifiedLDPEfilmappearedsmooth