Determination of Fe ²⁺ and Co ²⁺ by a Multiple‐Target Colorimetric Chemosensor with Low Detection Limit in Aqueous Solution

Abstract

Abstract A highly effective colorimetric chemosensor DPKP, N′‐(di(pyridin‐2‐yl)methylene)‐6‐hydroxypicolinohydrazide, was synthesized. DPKP sensed Fe 2+ and Co 2+ with the changes of color from colorless to blue and yellow, respectively, without severe inhibition from other metal ions. Binding interactions of DPKP with Fe 2+ and Co 2+ were analyzed to be 1:1 and 2:1 with Job plot and ESI‐MS analyses, respectively. In particular, DPKP has low detection limits for Fe 2+ (0.60 μM) and for Co 2+ (0.22 μM). In addition, DPKP could be used for quantification of Fe 2+ and Co 2+ in environmental samples.