Study On Electrochemical Sensors Based On Transitional Metal Carbon Nanocomposites

Electrochemical sensor as an important means of analysis,become the research hotspot in recent years.It electively determine material and the content of material mainly by the electrochemical signal between the electrode materials and the detection of objects.Therefore,construction of sensor electrode materials not only have excellent detection indicators(such as low detection limit,high sensitivity,wide the linear range),but also have low price,stable performance,good reproducibility and other characteristics of industrialization.In recent years the introduction of nanotechnology for its unique physical and chemical properties such as large surface area,high catalytic activity and biological compatibility,effectively improve the performance of the sensitivity and the stability of the sensor,and greatly promoted the development of sensor.In order to find a simple and efficient electrode material,in this paper we combined the conductivity and special structure of graphene with characteristics of transition metals and their compounds.A series of studies on the electrocatalytic oxidation of small organic molecules were carried out:一、Reduction of graphene oxide supported Fe S nanoparticles as a novel electrochemical sensor for simultaneous determination of dopamine and paracetamolIn this paper,Fe S nanoparticles anchored on reduced graphene oxide(r GO)nanosheets are synthesized via a facile direct-precipitation method.For the first time,a novel electrochemical sensor is developed based on Fe S/r GO nanosheets modified glassy carbon electrode(GCE).It has been proved that the resultant Fe S/r GO/GCE sensor is very suitable for the individual and simultaneous measurement of dopamine(DA)and acetaminophen(AC)and delivers excellent anti-interference ability to ascorbic acid(AA)and uric acid(UA).Under optimum conditions with differential pulse voltammetry method,a broad linear response versus the concentrations of DA and AC has been observed in the ranges of 2.0 to 250.0 μM and 5.0 to 300.0 μM,respectively.The detection limits for DA and AC are 0.098μM and 0.18μM,respectively.Furthermore,the as-obtained sensor has been successfully utilized in real samples and satisfactory results have been achieved.Consequently,by virtue of its outstanding electrocatalytic activity,excellentsensitivity,and longtime stability,theas-obtained Fe S/r GOmodifiedelectrode canbe considered as a new promising DA and AC sensor.二、Electrocatalytic oxidation of ethanol on Ni clusters supported on graphene oxideIn this work,the nikel nanoparticles uniformly supported on reduced graphene oxide(Ni/RGO)nanosheets were prepared by a simple and facile wet-chemical method.And the Ni/RGO nanocomposites modified glassy carbon electrode(GCE)(i.e Ni/RGO/GCE)displayed a good electrocatalytic activity toward ethanol oxidation in alkaline solution.Moreover,it was for the first time suggested that the anodic peak emerged in the potential negative-going sweep might be attributed to the oxidation of ethanol or acetaldehyde generated by ethanol oxidation in the positive-going scan instead of other reasons reported in related literature.Besides,surprisingly it could be speculated that the as-prepared Ni/RGO were of small nickel(Nin,n=1-6)cluster structures according to the electron transfer numbers of electrode reaction of Ni/RGO/GCE in blank(1.0M Na OH)solution in various scanning speed.This work was useful to further explore the mechanism of ethanol oxidation reaction in the fuel cells.三、Facile simultaneous electrochemical determination of epinephrine and acetaminophen in pharmaceutical samples and biological fluids by A novel sensor of Co Al OOH coated on Graphene OxideIn this paper,we using the layer structure of hydrotalcite(Co Al-LDH),with the step of further oxidation of hydrotalcite Co Al OOH.Through combine nanoplates with graphene oxide to constructe electrochemical sensor to determine adrenaline(EP)and acetaminophen(AC)in biological fluids and drugs.Co Al OOH/GO sensor showed a excellent anti-interference ability and good sensitivity,so as to realize the application of Co Al OOH/GO/GCE electrode in biological fluid samples and drug detection.At the optimum experimental conditions,get a wide linear range and lower detection limit inthe determination of EP and AC range of 0.1-25 μM and 0.1-30 μMthe detection limit is 0.023μM and 0.058μM(S/N=3).Due to its special structure and excellent electrochemical performance of Co Al OOH/GO/GCE modified electrode can be used as a new type of EP and AC sensor.