The behavior of dithizone (DTZ), an easily available dye has been studied for the first time in chromogenic
sensing of CN as an anionic species and for Co2+ as a cationic species in DMSO/H2O media. So employing
DTZ an efficient colorimetric chemosensor was afforded with a chromogenic selectivity for Co2+ over
other cations with detection limit of 0.04 lmol L1. The complex of Co2+ with DTZ also displayed ability
to detect up to 0.43 lmol L1 CN (K+ salts) among other competing anions through a fast response time
of less than 30 s which is much lower than most recently reported chromogenic probes. The linear
dynamic ranges for the determination of Co2+ and CN were 0.3–4.4 and 3.3–58.6 lmol L1 respectively.
This method could have potential application in a variety of cases requiring rapid and accurate analysis of
Co2+ and CN for human serum and water samples.