Electrochemical investigations of potassium ferricyanide and dopamine by sodium dodecyl sulphate modified carbon paste electrode: A cyclic voltammetric study

Abstract

A carbon paste electrode (CPE) modified by sodium dodecyl sulphate (SDS) was used for the detection of K 3Fe(CN) 6 and dopamine. Cyclic voltammetry (CV) demonstrated improved response of K 3Fe(CN) 6 and dopamine sensor at SDS/CPE compared to bare CPE. The effect of SDS concentration on the electrode quality also reveals that SDS formed a monolayer on a carbon paste electrode surface with a high density of negative charged end directed outside the electrode. On the formation of a SDS monolayer, the structure of the electrode interface changed significantly and the electrode/solution interface was replaced by the SDS monolayer/solution interface. The detection limit for K 3Fe(CN) 6 is 1 × 10 −4 M and dopamine 1 × 10 −7 M.