Properties And Application Of Electrochemical Biosensors Based On Nanocomposites With Mo Compounds

Nowadays,sensors are widely used and have practical significance.Among them,the electrochemical biosensors are accepted due to its simple and small equipment,environmental,high sensitivity,simple operation,good specificity,low cost and fast analysis.In this paper,a variety of new composite nano-materials is used to prepare our modified electrode.We used the infrared spectroscopy(IR),X-ray powder diffraction(XRD),x-ray photoelectron spectroscopy(XPS),energy dispersive X-ray spectroscopy(EDX),scanning electron microscopy(SEM),and transmission electron microscopy(TEM)to character the modified electrodes.The electrocatalytic properties of the modified electrode were studied by cyclic voltammetry(CV),chronoamperometry(I-t)and differential pulse voltammetry(DPV).Meanwhile,the determination of various biological substances in the serum samples was carried out.Firstly,a novel electrochemical sensor was fabricated successfully by the modification of a glassy carbon electrode(GCE)with a composite of nanoparticles of Polyoxometalates(Na5[IMo6O24]·3H2O),Graphene Oxide(GO)and Pt nanocomposite.Energy dispersive X-ray analysis(EDX),scanning electron microscopy(SEM),Infrared Spectrometer(IR),Cyclic voltammetry(CV),I-t and differential pulse voltammograms(DPV)were performed to characterize the electrochemical behavior and surface characteristics of the modified electrode.The results show that the modified electrode with nanomaterials not only maintains the electrocatalytic properties of heteropoly acid,but also increases the specific surface area of the modified electrode.Compared with a bare GCE and a GCE modified with GO and IMo6,the proposed electrode(Pt/IMo6/GO-GCE)exhibited high stability,fast response,good conductivity,excellent selectivity,sensitivity and large surface area characterization mainly due to the interaction between GO,IMo6 and Pt nanoparticles.For the oxidation of AA,DA and UA in the 0.05 M H2SO4 solution and the scan rate of 100mv/s,the correlation coefficients were found to be 0.999,0.999 and 0.998 and a low limit of detection of 3.0 ?M,0.22 ?M and 0.72 ?M,respectively.Therefore,this modified electrode has been successfully employed for the determination of AA,DA and UA in real samples.Secondly,Nonenzymatic electrochemical sensor catalytics the glucose by the method of amperometric,then we can get glucose content.So this modified electrode can be applied to determine the real sample.A ZnO-MoO3 hybrid was deposited on the surfaces of carbon material creating a flexible electrode.It was characterized by scanning electron microscopy(SEM),Elemental analysis,X-ray diffraction(XRD),X-ray photoelectron spectrum(XPS),Fourier transform infrared spectroscopy(FT-IR)and Electrochemical method.All resultsclearly indicate that ZnO-MoO3-C hybrid materials were distributed on carbon material,ZnO-MoO3-C/PDDA-GCE was successfully modified,and it appears excellent electrocatalytic properties.We characterize the electrocatalytic of the ZnO-MoO3-C/PDDA-GCE towards the oxidation of glucose and found that the proposed electrode(ZnO-MoO3-C/PDDA-GCE)exhibited better properties comparing with a bare GCE and a GCE only modified with ZnO or MoO3.The sensitivity of this modified electrode was 69.5 ?AmM-1cm-2 with a limit of detection of 1.74 ?M and its linear range is 6-700 ?M with a correlation coefficient of 0.9989.Therefore,the proposed electrode exhibited green,economic,high stability,enhanced electrocatalytic activity,fast response,good conductivity,excellent selectivity and sensitivity and large surface area characterization so that it has been successfully applied for the determination of glucose in human blood serum with a strong practicality.