Functionalized vertically aligned ZnO nanorods for application in electrolyte-insulator-semiconductor based pH sensors and label-free immuno-sensors

摘要

VerticallyalignedZnOnanorodsweregrownonaSiO2/Sisurfacebyoptimizationofthetemperatureandatmosphereforannealingoftheseed.Theseedlayerannealedat500°Cinvacuumprovidedwellseparatedanduniformseedswhichalsoprovidedthebestconditiontogetdenselypacked,uniformlydistributed,andverticallyalignednanorods.Thesenanorodsgrownonthesubstrateswereusedtofabricateelectrolyte-insulator-semiconductor(EIS)devicesforpHsensing.EtchingofZnOatacidicpHpreventsthedirectuseofnanorodsforpHsensing.Therefore,thenanorodsfunctionalisedwith3-aminopropyltriethoxysilane(APTES)wereutilizedforpHsensingandshowedthepHsensitivityof50.1mV/pH.APTESisalsoknowntobeusedasalinkertoimmobilizebiomolecules(suchasantibodies).TheEISdevicewithAPTESfunctionalizednanorodswasusedforthelabelfreedetectionofprostate-specificantigen(PSA).Finally,voltageshiftsof23mVand35mVwereobservedwithPSAconcentrationsof1ng/mland100ng/ml,respectively...