A novel 2,6-dicarbonylpyridine-based fluorescent chemosensor for Co2+ with high selectivity and sensitivity

Abstract

A novel fluorescence chemosensor based on 2,6-dicarbonylpyridine was designed and synthesized and its photophysical properties were characterized. Upon coordination of Co²⁺ by the central 2,6-dicarbonylpyridinyl functional group, the chemosensor 2,6-bis(4-diphenylamino-styrylcarbonyl)pyridine (PhPy) showed nearly complete fluorescence quenching, while no fluorescence response was seen towards other competing cations. The experimental results show the chemosensor is highly selective and sensitive towards Co²⁺ in the presence of competing ions, even in the ppb range. Job plot analysis was carried out and the results suggested that the binding of PhPy and Co²⁺ was probably a 2 : 1 stoichiometry.