Study On Electrochemical Biosensor And Electrodeposition Of Nickel-based Metal Nanometer Material Composite

Diabetes is one of the major diseases threatening human life and health.Although there is no effective cure,frequent monitoring of blood glucose in diabetic patients can effectively prevent induced diseases.Therefore,accurate,high-efficient and fast blood glucose detection is particularly important for clinical diagnosis and personal prevention and control.Due to the feature of high stability,high repeatability,fast response and low environmental dependence,the non-enzymatic electrochemical glucose sensor shows great potential in glucose detection.Nano-transition metals compounds are considered as ideal materials for new generation of enzyme-free glucose sensors owing to their high biocompatibility,high electrochemical activity,low cost,and strong charge transfer and adsorption capability.At present,most transition metal compounds have poor conductivity,which greatly limits their application in electrochemical sensing.In this paper we are trying to prepare nickel-based electrocatalytic materials using electrochemical deposition method in order to enhance their electrochemical activity by designing nickel-based alloys(NiAu,NiPt and NiCo),controling morphology(NiO/Au nanotubes),and combining noble metal.Moreover,we also intend to design the disposable enzyme-free glucose electrochemical sensor electrode based on carbon paper substrate,and investigate its glucose sensing performance The followings are the main research contents in our project:(1)Preparation of the bimetallic NiAu alloy dendrites directly on the carbon papers using template free electrodeposition approaches.The effects of different Ni-Au ratios on the morphology,structure and electrochemical activity of the alloys were studied.The results show that NiAu-10 has the highest electrocatalytic oxidation activity of glucose.In addition,the NiAu-10 electrode had been systematically studied for its enzyme-free glucose sensing performance.The results showed that NiAu-10 had higher electrocatalytic glucose oxidation activity than pure Ni and other NiAu alloy electrodes.It had an ultrahigh sensitivity of 4035.4?A·mM-1·cm-2,as well as an extremely wide linear range from 1?M to 3mM and a low detection limit of 0.2?M.In addition,the sensor constructed by NiAu-10/CP had good selectivity to interfering substances such as Ur,glutamic acid,lysine,Cl-,L-leucine,L-valine and proline.The enhanced electrochemical performance may be due to the dendrite structure and the low charge transfer resistance originating from the synergistic effect of Ni and Au.(2)The designing of NiO/Au core-shell nanotubes on carbon paper by multielectrodeposition method using ZnO nanorods as sacrified templates.The effect of Au content in the inner layer on the morphology structure and electrochemical performance of NiO/Au composite core-shell nanotubes was studied.It was found that the electrochemical oxidation activity of NiO/Au-10 was much higher than that of NiO nanotubes and other NiO/Au composite nanotubes.The electrode showed excellent electrochemical performance on non-enzymatic glucose sensing with sensitivity of 5536.225?A·mM-1·cm-2,the linear range of 1?M to 6mM,and the detection limit of 0.25?M.Furthermore,the detection of serum samples showed that it had strong feasibility in the analysis of glucose samples.The enhanced electrochemical performance may be due to the special tubular core-shell structure and the low charge transfer resistance originating from the synergistic effect of NiO and Au.(3)The preparation of NiPt nanosheets on carbon paper by one-step electrodeposition.The effects of Ni-Pt ratio on the morphology,structure and electrochemical activity of the materials were investigated.And NiPt-3 displayed the best performance among samples with other ratios towards electrochemical glucose oxidation.Furthermore,the enzyme-free electrochemical glucose sensing performance of NiPt-3 had been investigated for electrochemical glucose determination with the linear range of 1?M to 10.8mM,the sensitivity of 2225.5?A·mM-1·cm-2,and the detection limit of 0.4?M.This kind of material also had better selectivity,wider linear range and higher sensitivity,which may be due to the synergistic effect of Pt and Ni and the nanosheets structure.In addition,the material could be used for actual serum samples detection.(4)The preparation of Pt/NiCo alloy nanosheets composites on carbon paper by two-step electrodeposition method.The effect of loading amount of Pt(NP)on the electrochemical activity and morphology of the materials was studied.The results show that all the Pt/NiCo had better electrocatalytic ability and electron transfer efficiency than pure NiCo.Pt/NiCo-3 had the best glucose sensing performance with the sensitivity 4903.43?A.mM-1·cm-2 and 2258.21 ?A.mM-1·cm-2 in two linear ranges of 1?M-8mM and 8mM-20mM.The material also had good selectivity and good sensing performance for real serum samples.The enhanced glucose sensing properties of Pt/NiCo composite may be attributed to the good selectivity of NiCo alloy,which can improve the anti-interference ability and electron transfer efficiency of the sensor.Moreover,loading of Pt(NP)can further improve its conductivity and increase the electron transfer efficiency in the process of electrocatalysis.