The Preparsion And Application Of Bimetallic Oxide Nanoarrays For Non-enzymatic Electrochemical Glucose Sensing

Glucose detection plays an important role in controlling diabetes more efficiently.The development of reliable methods for accurate glucose detection is significant in clinical medicine.Although electrochemical enzymatic glucose sensor has high sensitivity and good selectivity,these sensors often require expensive enzymes.While enzyme immobilization is difficult and enzyme is unstable.Therefore,it is highly attractive to develop electrochemical non-enzymatic glucose sensors.With the development of nanotechnology,more and more metal and nanocomposite materials are applied to the research of enzyme free glucose sensors.more and more metal and composite nanomaterials are applied to the research of non-enzyme glucose sensors.Co₃O₄ is one of nanomaterials.Although the source of Co is rich and the safety,the electrical conductivity of Co₃O₄ is poor.And most of the Co₃O₄ nanomaterials still need polymer crosslinker to immobilization on the surface of the electrode,which may obscure some of the active sites to a certain extent,thus reducing the catalytic activity.It is found that the transition metal ions can exchange Co²⁺（Co₂）³⁺O₄ with Co²⁺to prepare bimetallic oxide.The bimetallic oxide is beneficial to the transfer of electrons because of the synergism between metal ions,thus showing superior conductivity and higher electrochemical activity compared to the single component metal oxide.This paper combines the advantages of bimetallic oxide and 3D nanoarray self-supporting electrode to construct a bimetallic oxide nanoscale electrode,which is used for the study of non enzyme glucose sensing.The main contents of this paper are as follows:（1）Cu Co₂O₄ nanowires arrays supported on carbon clothe（Cu Co₂O₄ NWAs/CC）was prepared via simple hydrothermal synthesis and subsequent calcination process.As a 3D binder-free electrode for non-enzymatic glucose sensing,Cu Co₂O₄ NWAs/CC shows high performance towards glucose in alkaline condition,with a wide detection range from 1μM to 0.93 m M,a low detection limit of 0.5μM（S/N=3）,and a high detection sensitivity of 3.93 mA m M^-11 cm^-2.Moreover,Cu Co₂O₄ NWAs/CC shows good selectivity towards common interference and good reproducibility for glucose detection.（2）Porous NiCo₂O₄ nanowire arrays supported on carbon cloth（NiCo₂O₄NWAs/CC）have been prepared via a facile hydrothermal synthesis method,followed by subsequent annealing in air.Benefiting from its porous structure and binary metal oxide composition,Ni Co₂O₄ NWAs/CC shows larger effective surface area and superior electric conductivity.Together with the bind-free 3D open electrode with larger specific surface area and more accessible active site,the present NiCo₂O₄ NWAs/CC electrode exhibits remarkable catalytic activity towards enzyme-free glucose sensing,with a high sensitivity of 4.12 mA mM^-1 cm^-2,a wide detection range from 1μM to 0.63 mM,low detection limit of 0.5μM（S/N=3）.Moreover,NiCo₂O₄ NWAs/CC also displays good selectivity and stability,and thus be reliable for glucose detection in human serum samples.（3）Porous ZnCo₂O₄ nanowire arrays supported on carbon cloth（ZnCo₂O₄ NWAs/CC）have been prepared via a facile hydrothermal synthesis method,followed by subsequent annealing in air.Benefiting from its porous structure and binary metal oxide composition,ZnCo₂O₄ NWAs/CC shows larger effective surface area and superior electric conductivity.And the present ZnCo₂O₄ NWAs/CC electrode exhibits remarkable catalytic activity towards non-enzyme glucose sensing,with a high sensitivity of 3.44m A mM^-1 cm^-2,a wide detection range from 5μM to 0.78 mM,and low detection limit of 5μM（S/N=3）.Moreover,ZnCo₂O₄ NWAs/CC also displays good selectivity and stability for glucose detection.