Highly Sensitive Glucose Biosensors Based On MoS₂-NiCo₂O₄ And NiCo₂O₄@MnO₂ Nanocomposites Owning Strong Coupling Effects

In recent years,with the improvement of living standards,the acceleration of life tempo and the changes of dietary habits,diabetes has become a serious epidemic.Long-term being in the high blood sugar level can cause irreversible damages to human tissues.Therefore,the rapid and accurate detection of blood glucose plays a vital role in the early detection,effective diagnosis and control of hyperglycemia.So far,many methods,such as high performance liquid chromatography,colorimetric biosensing and electrochemical biosensors,have been adopted to realize the sensitivite and accurate glucose detection.Among them,electrochemical biosensors have drawn much attention due to the merits of high sensitivity,low cost,simple operation and portability.Because of the disadvanteges of enzyme glucose biosensor,such as the complexities of the electrode immobilization process and the high sensitivity to temperature,pH and humidity,nonenzymatic glucose electrochemical biosensors have been developed.Glassy carbon electrode(GCE)owns the defects of high detection potentials and low sensing signals.Nanomaterials modified GCE can significantly improve the conductivity and electron transfer rate,enhance the interaction between the electrode and glucose,and promote the electrochemical response of the electrode to low concentration of glucose.Therefore,the researches of glucose electrochemical sensors focus on the catalytic centers and supported substrates.Single-layer or few-layers MoS2 exhibit unique physical and chemical properties,and few-layers MoS2 is an excellent charge collector.NiCo2O4 owns the advantages of high electronic conductivity,good biocompatibility,non-toxic and et al.MnO2 has high electrocatalytic activity and abundant earth reserves.Therefore,two nanocomposites,MoS2-NiCo2O4 and NiCo2O4@MnO2 will be constructed to enhance the electrocatalytic performance to glucose through the synergistic coupling between two components.The structure,composition electrochemical properties of the two nanocomposites will be characterized by X-ray diffraction(XRD),scanning electron microscope(SEM),transmission electron microscope(TEM),X-ray photoelectron spectroscopy(XPS),electrochemical impedance spectroscopy(EIS)and cyclic voltammetry(CV).The results prove that MoS2-NiCo2O4/GCE and NiCo2O4@MnO2/GCE exhibit enhanced electrocatalytic activity for the oxidation of glucose.The sensors show a broad linear range,high sensitivity of 1731.04,2887.57 ?A/(mmol/L·cm2),low detection limit(0.153,0.036 ?mol/L)at the applied potential of + 0.418 V and + 0.545 V,respectively.The two nanocomposites also exhibit good resistance to ascorbic acid,uric acid,dopamine,chloride and monosaccharides.In addition,they have good reproducibility,repeatability and long-term stability.The excellent electrocatalytic activities for glucose suggest that the two nanomaterials are promising materials in the field of nonenzymatic glucose biosensors.