New chemically modified carbon paste (CPEs) and screen-printed electrodes (SPEs) were fabricated incorborating copper oxide nanoparticles (CuO NPs) as a neutral ionophore and explored as Cu(II) selective electrodes. The fabricated electrodes were satisfactory applied to determine Cu(II) ion in pure solutions and different real spiked water samples using the proposed potentiometric method. The results obtained applying MCPEs and MSPEs agree well with the inductively coupled plasma atomic emission spectrometry (ICP-AES).