JSolidStateElectrochem(2012)16:3747–3752DOI10.1007/s10008-012-1813-5

ORIGINALPAPER

DirectelectrochemistryofglucoseoxidaseimmobilizedonTiO2–graphene/nickeloxidenanocompositefilmanditsapplication

Chun-XuanXu&Ke-JingHuang&Xue-MinChen&Xiao-QinXiong

Received:2April2012/Revised:23June2012/Accepted:2July2012/Publishedonline:13July2012#Springer-Verlag2012

AbstractAnovelelectrochemicalplatformbasedonnickeloxide(NiO)nanoparticlesandTiO2–graphene(TiO2–Gr)wasdevelopedforthedirectelectrochemistryofglucoseoxidase(GOD).Theelectrochemicalbehaviorofthesensorwasstudiedusingcyclicvoltammetryandchronoamperom-etry.Theexperimentalresultsdemonstratedthatthenano-compositewellretainedtheactivityofGODandthemodifiedelectrodeGOD/NiO/TiO2–Gr/GCEexhibitedex-cellentelectrocatalyticactivitytowardtheredoxofGODasevidencedbythesignificantenhancementofredoxpeakcurrentsincomparisonwithbareGCE.Thebiosensorrespondedlinearlytoglucoseintherangeof1.0–12.0mM,withasensitivityof4.129μAmM 1andadetectionlimitof1.2×10 6Munderoptimizedconditions.Theresponsetimeofthebiosensorwas3s.Inaddition,thedevelopedbiosensorpossessedgoodreproducibilityandstability,andtherewasnegligibleinterferencefromotherelectroactivecomponents.

KeywordsTiO2–graphene.Nickeloxidenanoparticles.Glucose.Glucoseoxidase.Biosensor

Introduction

Increasingattentionhasbeenfocusedonthestudyofthedirectelectrochemistryofproteinsbecauseofitssignifi-canceinbothprobingthenatureofenergyconversionprocessesinbiologicalsystemsanddevelopmentofthird-generationbiosensors[1,2].However,itisdifficultfor

C.-X.XuK.-J.Huang(*)X.-M.ChenX.-Q.XiongCollegeofChemistryandChemicalEngineering,XinyangNormalUniversity,Xinyang464000,China

e-mail:kejinghuang@

proteinstoexchangeelectronsdirectlywithbaresolidelec-trodesbecausetheelectroactivecenterofproteinsisdeeplyburied.Thedirectelectrontransferbetweenglucoseoxidase(GOD)andelectrodecannotbeachievedeasily.Nanomate-rialshavebeenwidelyusedforconstructionofbiosensorduetotheintrinsicadvantages,suchaslowcost,goodthermalstability,andlargesurfacearea.Especially,metalnanoparticlescanprovideasuitablemicroenvironmentforbiomoleculesimmobilizationretainingtheirbiologicalac-tivityand,tofacilitateelectrontransferbetweentheimmo-bilizedproteinsandelectrodesubstrates,haveledtoanintensiveuseofthosenanomaterialsfortheconstructionofelectrochemicalbiosensorswithenhancedanalyticalperfor-mancewithrespecttootherbiosensordesigns.Duetotheiruniquechemicalandphysicalproperties,manykindsofmetalnanoparticles,suchasgoldnanoparticles,platinumnanoparticles,andAgnanoparticles,havebeenusedinthefabricationofbiosensorsforglucoseanalysis[3–7].

Nickeloxide(NiO)nanoparticleshavereceivedconsid-erableattentioninrecentyearsduetotheircatalytic,optical,electronic,andmagneticproperties[8,9].Theeasyprepa-ration,electroinactivityinphysiologicalpHsolutions,andhighporosityareadvantagesofNiOnanomaterialsfortheentrapmentofelectrontransfermediators.TheycanbeusedfortheimmobilizationofdifferentmoleculesbasedontheuniquepropertiesofNiOnanoparticles.Forexample,theuseofNiOnanoparticlesfortheimmobilizationofbiomo-leculesandtheirapplicationsforhydrogenperoxideandglucosedetectionhasbeenreported[10,11].

Graphene(Gr)isamonolayeroftightlypackedcarbonatoms.Itissuitedforelectrochemicalapplicationsduetoitshighelectricalconductivity,largesurfacearea,uniquehet-erogeneouselectrontransferrate,andlowproductioncosts.Recently,Grhasbeenwidelyutilizedinchemical,electron-ic,information,energy,materials,biologicalmedicine,andotherfields[12,13].However,manyoftheinterestingand