Rhodamine B Functionalised Schiff Base Chemosensor for Effective Detection of Cu(II) Ions in Water Sample

Schiff Base sensor (E)-3-(((3',6'-bis(diethylamino)spiro[isoindoline-1,9'-xanthen]-2-yl)imino)methyl)naphthalen-2-ol (SBRB2) was conceived and produced by employing a new Rhodamine functionalization. The ability of the sensor SBRB2 to detect Cu(II) was studied using fluorescence and UV-Vis spectroscopy. The sensor SBRB2 indicated sensitivity and specific selectivity to Cu(II) among other competitive metal ions based on fluorescence studies. A new emission peak appeared at 580 nm only in the presence of Cu(II). The chelation of the ligand with Cu (II) was responsible for the sensitivity to Cu (II). The binding constant and detection limit of the SBRB2: Cu (II) complex were found by the fluorescence titration to be 1.18 × 10⁴ M^-1 and 3.03 × 10^-6 M, respectively. It showed the 1:1 complexation between SBRB2 and Cu (II) was conformed from the DFT and TD-DFT study of SBRB2 in both solvent and gas phase.