A New Rhodamine B Derivative As a Colorimetric Chemosensor for Recognition of Copper(II) Ion

A new rhodamine-based sensor 1 was designed and synthesized by incorporating rhodamine B and benzimidazole moieties Sensor 1 exhibits high selectivity and sensitivity to Cu2+ in CH3CN-water solution (HEPES buffer, pH = 7 0) with an obvious color change from colorless to pink Other metal ions such as Hg2+, Ag+, Pb2+, Sr2+, Ba2+, Cd2+, Ni2+, Co2+, Fe2+, Mn2+, Cu2+, zn(2+), Ce2+, Mg2+, K+ and Na+ had no such color change and have no significant Influence on Cu2+ recognition process The interaction of Cu2+ and sensor 1 was proven to adopt a 1 1 binding stoichiometry and the recognition process is reversible