Optical chemosensing of arsenite and ferrum ions using 4-(Benzylideneamino)-1,5-dimethyl-2-phenyl-1,2-dihydropyrazol-3-one

Optical sensors have drawn considerable attention these days due to their quick, easy and on-site detection of metal ions. In this research, a Schiff base “4-(Benzylideneamino)-1,5-dimethyl-2-phenyl-1,2-dihydropyrazol-3-one (V-AAP)” was studied for its naked eye chemosensing abilities to detect metallic ions, i.e., Fe 2+ , Fe 3+ , Mn 2+ , Co 2+ , Cu 2+ , Zn 2+ , Ag + , Hg 2+ , Pb 2+ and AsO 2 − . This colorimetric probe exhibited selective color change from colorless to brownish yellow, pale yellow and greenish yellow for Fe 2+ , Fe 3+ and AsO 2 − ions, with detection limits of 9.986 × 10 –7 M (0.056 ppm), 1.285 × 10 –6 M (0.072 ppm) and 2.465 × 10 –5 M (2.64 ppm), respectively. Moreover, binding ratios of V-AAP and Fe 2+ , Fe 3+ and AsO 2 − ions were calculated to be 1:1 with binding constants 1.22 × 10 2 M −1 , 1.30 × 10 3 M −1 and 9.30 × 10 1 M −1 , correspondingly. Graphical Abstract