Cyclic Voltammetric Studies of Serotonin at Sodium Dodecyl Sulfate Modified Carbon Paste Electrode

Electrochemical oxidation of serotonin has been studied at carbon paste electrode in 0.1M pyrophosphate buffer using cyclic voltammetric (CV) technique. The adsorption of sodium dodecyl sulfate (SDS) at carbon paste electrode was investigated. The results showed that SDS exhibited two types of adsorptive behavior at carbon paste electrode at different concentration ranges viz. i) monomer adsorption at concentration below 3x10-3 M and monolayer adsorption at concentrations higher than 3x10-5 M SDS onto the surface ii) 5μL monomer adsorption and monolayer adsorption at concentrations higher than 60μL of 3x10-5 M SDS into the solution. In the monomer adsorption range the adsorption of SDS could effectively reduce the charge transfer rate. However the surface properties of the carbon paste electrode drastically changed on the formation of a SDS monolayer.