voltammetric determination of cysteine at a carbon paste electrode modified with cu(ii)-salen complex

the electrochemical behavior of a modified carbon paste electrode (mcpe) with n,n′ethylenbis(salicylideneiminato)copper(ii) complex ([cu(ii)-salen]) was investigated as a newsensor for cystein. the britton-robinson buffer with ph 5, 10% modifier in electrode, potentialscanning rate of 20 mvs-1 and puls height of 50 mv were used as the optimum condition for thedetermination of cysteine using carbon paste electrode modified with cu(ii)-salen complex. underthese optimum conditions, the resulting electrode demonstrated linear response with cysteineconcentration in the range of 1-10 and 10-80 μm. the effects of potential interfering species werestudied and it was found that only thiocyanate ion interfered in cysteine determination and theproposed procedure was free from most other interferences.