A new electrochemical sensor for the selective detection of Cd2+ ion based on Schiff base, 1,1'-(biphenyl-4,4'-diylbis(azan-1-yl-1-ylidene))bis(methan-1-yl-1-ylidene) dinaphthalen-2-ol (BZNA) having from both moieties 2-hydroxy-1-iminomethylnaphthalene and benzidine core is presented. BZNA was synthesized by condensation reaction and then fully characterized. A thin film of BZNA was fabricated onto Nafion/Glassy carbon electrode (GCE) with 5.0% ethanolic solution of Nafion as the conducing coating agent. A slurry of BZNA was used to coat the GCE (GCE; 0.0316 cm(2)) as a thin layer for the selective detection of Cd2+ ion in an aqueous solution. A linear calibration curve that has a linear dynamic range (LDR) from 0.1 nM to similar to 0.1 mM is obtained. From the slope of the plot, the calculated sensitivity, limit of detection (LOD), and limit of quantification (LOQ) of Cd2+ ion were found to be 2.93 mu A mu M-1 cm(-2), 32.0 +/- 1.62 pM, and 106.67 pM respectively. This novel approach might pave the way for the development of heavy metal ion detection process in the fields of environmental and healthcare.