| Tocopherolis an important part of vitamin E,which is a common liposoluble vitamin,including α-,β-,γ-,δ-tocopherol,and α-,β-,β-,δ-tocotrienol.Because of the complex structure of vitamin E,a-tocopherol is usually detected as the most bioactive substance of vitamin E.As an important promoter of human civilization,materials are eternal treasures,in the eyes of researchers,brilliant as ever.Nowadays,conventional materials have been difficult to meet the growing needs of people,conventional materials are rich everywhere and inexpensive,but the function of a single decision they can not provide a wide range of applications.The development of intelligent and information applications determines that materials should also be transformed into new directions,and various advanced materials are constantly being discovered,and the diversity of materials is also a new era.Graphene is a two-dimensional material with only atomic thickness,which exhibits good electrical conductivity,thermal conductivity,and flexibility.In many areas,have shown great potential in recent years,highlighting the outstanding characteristics of the study,and its surface functional potential has brought a huge graphene family,the derivatives of these graphene,Also found a further superiority.This work includes two parts:1.We prepared a graphene modified glassy carbon electrode to detect a-tocopherol.Compared to reported methods,our GNC/GC electrode is cheap and simply to prepared.The method was differential pulse voltammetry(DPV).First,enrich the a-tocopherol in solution,and then,detect with DPV.The response current is linearly to the concentration of a-tocopherol.The reaction solution is the mixture liquid of ethanol and water,while tocopherol dissolved well in organic phase and the electrochemical method responsed better in water phase.Therefore,the mixture solution can increase the response of the a-tocopherol2.We also used another electrode that based on modified carbon nanotubes.In the second work,the base electrode is selected as a silver electrode,and the silver electrode is pre-polarized in NaOH solution to expose the surface of the fresh metal silver and silver-nanooxide-particles,and then electroplate graphene.This aspect is the use of metal silver catalytic,on the other hand,graphene is also catalytic,and according to SEM of the surface of modified electrode,the electrode surface area increased obviously,which are conducive to the increase the response.The detection method is positive scan polarization reverse catalytic voltammetry(PSPRCV)(2014).This method was developed based on cyclic voltammetry.For PSPRCV,like cyclic voltammetry,the potential is firstly scanning positively from initial to switching potential,the working electrode is anodic polarized,then the potential is scanning reversely(negatively)to the initial,meanwhile the a-tocopherol will be catalytic oxidized by the electrode reaction intermediate products,and the voltammogram is recorded.Finally,the blank data is deducted from the sample data.The difference value peak current is proportional to the bulk concentration of a-tocopherol.This method can avoid the interference of background current. |
