Electrochemical and Chromogenic Sensors Based on Ferrocene Appended Chalcone for Selective Quantification of Copper (II)

The chromogenic, voltammetric and potentiometric sensors based upon the novel ferrocene appended chalcone (FAC) have been developed for the selective detection of Cu (II) ions. In UV/visible measurements, the addition of Cu (II) ion into the FAC resulted in the disappearance of low energy band associated with hypsochromic shift of 30 nm of the high energy band. This perturbation in the absorption spectrum is well appreciated by naked eye inspection. The chromogenic sensor exhibited the concentration range of 3.00 × 10−5 to 3.50 × 10−6 M with detection limit of 6.00 × 10−7 M. The cyclic voltammetry (CV) of FAC showed a reversible redox couple (Fe2+/Fe3+), when scanned in between the potential range of 0.4 V to -0.2 V vs. Ag/Ag+. The CV of FAC undergoes electrochemical changes due to the formation of FAC-Cu (II) complex on addition of Cu (II) ions. The voltammetric sensor can work within the concentration range of 5.00 × 10−5 to 4.00 × 10−4 M with detection limit of 2.00 × 10−6 M. The potentiometric response of polyvinylchloride (PVC) based solid contact coated graphite electrode (CGE-1) was linear within the Cu (II) ions concentration range of 1.00 × 10−1 to 5.00 × 10−7 M and showed near Nernstian slope of 28.5 mV/decade with the detection limit of 1.78 × 10−7 M. No significant interference was observed from other diverse metal ions. The analytical usefulness of proposed sensors has been validated further by estimating the Cu (II) ions in various sample matrices with excellent results.