A Unique Thiosemicarbazide-Based Colorimetric Chemosensor for Fe(2+)in Pure Aqueous Solution with the Lowest Detection Limit

A unique colorimetric chemosensorHy-bpbased on thiosemicarbazide was prepared.Hy-bpshowed an obvious red-shifted spectrum and unique color change from colorless to deep green only for Fe2+. Detection limit for Fe(2+)was 0.34 mu M, which is the lowest among those of colorimetric chemosensors previously reported for Fe(2+)in pure aqueous solution.Hy-bpcan be utilized in paper strips and water samples as a colorimetric sensor for detecting Fe2+. The sensing mechanism ofHy-bpfor Fe(2+)was demonstrated by UV-vis spectroscopy, Job plot, FT-IR and(1)H NMR titrations.