Highly selective and sensitive membrane sensors for copper(II) ion based on a new benzo-substituted macrocyclic diamide 6,7,8,9,10-hexahydro-2H-1,13,4,7,10-benzodioxatriazacyclopenta-decine-3,11(4H,12H)-dione

Novel PVC membrane (PME) and coated graphite (CGE) Cu2+-selective electrodes based on 5,6,7,8,9,10-hexahydro-2H-1,13,4,7,10-benzodioxatiazacyclopentadecine-3,11(4H,12H)-dione are prepared. The electrodes reveal a Nernstian behavior over wide Cu2+ ion concentration ranges (1.0 x 10(-7) -10 x 10(-1) M for PME and 1.0 x 10(-8) -1.0 x 10(-1) M for CGE) with very low limits of detection (7.8 x 10(-8) M for PME and 9.1 x 10(-9) M for CGE). The potentiometric responses are independent of the pH of the test solutions in the pH range 2.7-6.2. The proposed electrodes possess very good selectivities for Cu2+ over a wide variety of the cations including alkali, alkaline earth, transitions and heavy metal ions. The practical utility of the proposed electrodes have been demonstrated by their use in the study of interactions between copper ions and human growth hormone (hGH) in biological systems, potentiometric titration of copper with EDTA and determination of copper content of a sheep blood serum sample and some other real samples.