Development and characterization of a copper optical sensor based on immobilization of synthesized 1-phenyl-1,2-propanedione-2-oxime thiosemicarbazone on a triacetylcellulose membrane

The new chromogenic reagent 1-phenyl-1,2-propanedione-2-oxime thiosemi-carbazone (PPDOT) was synthesized and utilized to prepare a novel sensing membrane (optode) for determination of Cu(II) by immobilization on triacetylcellulose membrane. PPDOT has an amino group and is covalently immobilized on a triacetylcellulose membrane. The sensing mechanism involves the complex formation between Cu(II) and immobilized PPDOT at pH 5.8, which results in increases in absorbance at 401 nm. The sensor shows sufficient repeatability, reproducibility, operational lifetime of 3 weeks, and a response time of about 8 min. Cu(II) could be determined in the range between 7.5 × 10−6 and 2.0 × 10−4 M with a detection limit of 8.0 × 10−7 M with a response time of 8 min. Most commonly coexisting ions do not interfere with the Cu(II) assay. This sensor was used for the determination of Cu(II) in water and alloy samples with satisfactory results.