The Study Of Cationic Surfactants Application In Aminophenol Modified Electrode

Surfactants are a kind of amphiphilic molecule with a polar head on one sideand a long hydrophobic tail on the other.Due to the amphiphilic structure ofsurfactants,these molecules could be absorbed in the interfaces and surfaces andsolubilization.Surfactants have some special properties with reducing the surface tension ofthe solvent and changing the surface state of the system.Surfactants are also easy toadsorption at the interface and form micelle in solution which can significantly alterelectrochemical properties of the electrode/electrolyte interface and affect theelectrochemical process.So surfactants have been widely used in electrochemical day afterday.Therefore,study the interaction of drug with surfactant and revealing the interactionlaw and mechanism of surfactants which are more important theoretical and practicalsignificant applications of the drug in the clinical.In this paper,the silver doped polyL-phenylalanine modified electrode Ag-PLPHE/GCE was prepared by cyclic voltammetricmethod and chronoamperometry.The electrochemical behaviors of neural medicationdopamine (DA) and uric acid (UA) were studied on the modified electrode in the presenceof different surfactants and discussed the process of electrode reaction.The major works asfollows:(1) The silver doped poly L-phenylalanine modified electrode was fabricated bycyclic voltammetric method. The electrochemical behaviors of dopamine in the presence ofcationic surfactant cetylpyridinium bromide have been studied by cyclic voltammetry andchronoamperometry at silver doped poly L-phenylalanine modified electrode. The resultsshowed that electrochemical oxidation of DA process in the micellar solution as same as inthe non-surfactant basically. However the electric charge of electrode surface and solutionhave been changed with adding different concentrations of cetylpyridinium bromide, thediffusion and absorption of DA has been influenced.(2)The electrochemistry behaviors of uric acid in the presence of cetylpyridiniumbromide micella by cyclic voltammetry on silver doped poly L-phenylalanine modifiedelectrode. The anodic peak potential changed slightly compared with inexistence surfactant. The anodic peak current was found to be remarkably dependent on the concentration of thesurfactant. The anodic peak current decreased with increasing concentration of CPB. Thepeak current of UA had linear relationship with the concentration of CPB in the range of8.00×10-7-1.00×10-5mol/L and1.00×10-5-1.00×10-4mol/L, while the detection limit is5.0×10-9mol/L.(3) The silver doped poly L-phenylalanine modified electrode was fabricated bycyclic voltammetric method. The electrochemical behaviors of dopamine in the presence ofcationic surfactant ethylrimethylammonium bromide, anionic surfactant sodiumdodecylsulfate and nonionic surfactant TritonX-100micellar aqueous solution have beenstudied by cyclic voltammetry and chronoamperometry at silver doped polyL-phenylalanine modified electrode. The results showed that electrochemical oxidation ofUA process in the micellar solution as same as in the non-surfactant basically. However theelectric charge of electrode surface and the solution have been changed with addingdifferent surfactants. The diffusions and absorption of UA has been influenced. The resultalso showed that the oxidation currents of UA decrease with the peak potential changesslightly in different surfactants. The ethylrimethylammonium bromide has a greatest effecton the peak currents of UA, mean while the sodium dodecylsulfate has a smallest effect.We discussed the existent state of surfactants in solution and the interaction withneural medication through summarizing the influence of different surfactants on thedopamine and uric acid’s electrochemical behaviors on the modified electrode.Experimental results shown that adding different surfactants will alter the electric charge ofelectrode surface and solution under specifically acidity.Then surfactants interact withdopamine and uric acid by electrostatic function.Moreover,the diffusion and absorption ofUA,DA have been influenced as the concentration of surfactants reached specifically valuewhich can form micellar aggregates.Thus the peak currents have been decreased on themodified electrode.