In summary, we have demonstrated the use of readily accessible
DTZ for highly selective and sensitive sensing of Co2+ in aqueous
medium. The resulting complex [Co(DTZ)2]2+ formed in situ,
can be used to detect the CN among other inorganic anions and
detection can be considered as an alternative approach for the
‘naked-eye’ colorimetric sensing of CN in DMSO/H2O (75:25 v/v)
medium. The results have provided a new opportunity to detect
CN through the use of a cationic chemosensor. There are several
advantages associated with this chemosensor for cyanide detection:
such as (i) our probe is commercially available; (ii) works in
aqueous DMSO solution; (iii) has high selectivity over fluoride, acetate
and benzoate and (iv) possess long-wavelength absorption.
The detection limit (signal-to-background, S/B) of [Co(DTZ)2]2+
was estimated to be 0.43 lmol L1. The sensitivity is close to the
maximum permissive level in drinking water, which is
1.9 lmol L1 according to the World Health Organization (WHO).
It can be used as a convenient and effective method to detect cyanide
in aqueous media.