Design of a copper (II) optode based on immobilization of dithizone on a triacetylcellulose membrane

The characterization of an optical sensor membrane is described for the determination of copper (II) based on the immobilization of dithizone on a triacetylcellulose membrane. This optode has a linear range of 0.83–16.28 μmol L−1 (52.7–1034 ng mL−1) for Cu2+ ions with a limit of detection of 0.2 μmol L−1 (12.7 ng mL−1) at a wavelength of 611 nm. The response time of optode is within 5–8 min depending on the concentration of Cu2+ ions. The selectivity of the optode to Cu2+ ion in the presence of other metal ions including Pb2+, Mg2+, Ca2+, Ba2+, Zn2+, Ni2+, Co3+, Mn2+, Cd2+, Bi3+, Fe3+ and Al3+ is high, with the exception of Hg+2 ion as the main interference which can be eliminated with iodide as the masking agent. The sensor can readily be regenerated with thiourea solutions. The sensor could be fully regenerated, and the color is fully reversible.