Herein,　a　novel　sensitive　electrochemical　sensor　for　copper(II)　based　on　Cu(I)　catalyzed　alkyne-azide　cycloaddition　reaction　(CuAAC)　is　described.　The　catalyst　of　Cu(l)　species　is　derived　from　electrochemical　reduction　of　Cu(II)　through　bulk　electrolysis　(BE)　with　coulometry　technique.　The　propargyl-functionalized　ferrocene　(propargyl-functionalized　Fc)　is　covalently　coupled　onto　the　electrode　surface　via　CuAAC　reaction　and　forms　propargyl-functionalized　Fc　modified　gold　electrode,　which　allows　a　good　and　stable　electrochemical　signal.　The　change　of　current　at　peak　(dl),　detected　by　differential　pulse　voltammetry　(DPV),　exhibits　a　linear　response　to　the　logarithm　of　Cu(II)　concentration　in　the　range　of　1.0　x　10(-14)-1.0　x　10(-9)　mol　L-1.　It　is　also　found　that　the　proposed　sensor　has　a　good　selectivity　for　copper(II)　assay　even　in　the　presence　of　other　common　metal　ions.　Additionally,　the　proposed　method　has　been　applied　to　determine　copper(II)　in　the　dairy　product　(yoghurt)　with　satisfactory　results.　(C)　2011　Elsevier　B.V.　All　rights　reserved.