Triphenyl Ether Amide as a Probe for Electrochemical and Optical Sensing of Copper, Cyanide and Arginine

Abstract

A novel triphenyl ether amide (TPEAM) derivative has been synthesises and developed as a probe for electrochemical and optical sensing of copper, cyanide ions and arginine in the presence of other amino acids. The ionophore is selective for the copper and cyanide ions among various cations and anions, with detection limits as 40 nM and 0.4 μM, respectively. Sharp anodic and cathodic peaks in the differential pulse voltammograms of the TPEAM-Cu(II) complex indicated a good complexing tendency of the ligand molecule and it was confirmed by spectrofluorimetry and 1H NMR titrations. TPEAM-Cu2+ complex further detected arginine, a semi-essential amino acid, in aqueous medium with a lower detection limit of 4 μM. Host-guest interactions between TPEAM and Cu2+ ions and intramolecular charge transfer interactions (ICT) for CN− ions are proposed as possible mechanisms for the sensing of respective ions. Cyanide detection followed a non-sequential mechanism. The application of TPEAM as a probe for Cu2+ ions has also been validated on food samples and the results are compared with atomic absorption spectroscopy.