A novel compound TPI with the unique ether-imine combination was synthesized in high yield and characterized by spectroscopic techniques. The binding behavior of TPI for various cationic species in CH3CN:H2O system was investigated and compared by spectroscopic and voltammetric techniques. Observable color change from dark yellow to colorless was found to be the first signaling system for the interaction of TPI with Cu2+ ions. Binding constant evaluated from UV-Vis studies were 0.2 x 10(6) M-1 and detection limit obtained was 50 nm. The highlight of the work is the ratiometric sensing of water content by TPI-Cu2+ complex in pure acetonitrile media proves the detection limit of water content in the medium as low as 0.06 ppb. Fluorescence studies showed the emission band at 490 nm which was quenched in presence of Cu2+ ions and a new blue-shifted emission band at 450 nm was observed. Electrochemically, TPI showed a major anodic peak at 1.05 V and a cathodic peak at 0.95 V along with small peaks at 1.35 V (anodic peak) and 0.5 V (cathodic peak) was observed which get shifted in presence of copper ions only. The optimized electrochemical method was successfully used for the detection of copper (II) ions from real samples as well. (C) 2016 The Electrochemical Society. All rights reserved.