Voltammetric determination of cysteine using carbon paste electrode modified with Co(II)-Y zeolite

► Ion exchange of zeolites remains when a Co(II)-zeolite Y was incorporated in carbon paste electrode. ► Voltammetric response of the electrode depends on the electroactive Co(II) species in the zeolite structure. ► Co(II) shows a catalytic behavior in the voltammetric determination of Cysteine. ► The proposed electrode showed good results for real samples.