A Unique Thiosemicarbazide‐Based Colorimetric Chemosensor for Fe²⁺ in Pure Aqueous Solution with the Lowest Detection Limit

Abstract

A unique colorimetric chemosensor Hy‐bp based on thiosemicarbazide was prepared. Hy‐bp showed an obvious red‐shifted spectrum and unique color change from colorless to deep green only for Fe2+. Detection limit for Fe2+ was 0.34 μM, which is the lowest among those of colorimetric chemosensors previously reported for Fe2+ in pure aqueous solution. Hy‐bp can be utilized in paper strips and water samples as a colorimetric sensor for detecting Fe2+. The sensing mechanism of Hy‐bp for Fe2+ was demonstrated by UV‐vis spectroscopy, Job plot, FT‐IR and 1H NMR titrations.

A New Chromone‐based Sequential Functioning Colorimetric Chemosensor for Cu2+ and Cysteine in Near‐perfect Aqueous Media

“…However, these methods have problems of low sensitivity, high‐priced equipment, and complicated analysis [7–11] . Meanwhile, optical detection methods like colorimetry have the advantages of being simple, sensitive, and cheap through immediate color variations [10,12–19] . For those reasons, it is needed to develop colorimetry sensors to simply detect metals or amino acids [20–23] …”

“…[7][8][9][10][11] Meanwhile, optical detection methods like colorimetry have the advantages of being simple, sensitive, and cheap through immediate color variations. [10,[12][13][14][15][16][17][18][19] For those reasons, it is needed to develop colorimetry sensors to simply detect metals or amino acids. [20][21][22][23] Copper is essential for physiological body functions like mitochondrial electron transfer, neurotransmission process, melanin production, and bone formation.…”