A novel thiosemicarbazide based chemosensor for colorimetric detection of Co2+ in commercial B12 vitamin and Co2+, Ni2+ simultaneously in aqueous media

ABSTRACT

In this study, a novel thiosemicarbazide-based Schiff-base chemosensor containing naphthalene moiety (TSNCS) was easily synthesised and used for colorimetric detection of Ni²⁺, Co²⁺ ions in real samples. Probe TSNCS displayed an obvious colour change from colourless to dark yellow in the presence of Co²⁺ and Ni²⁺ in aqueous acetonitrile solutions. The interaction-binding mode of probe TSNCS with Co²⁺ (TSNCS-Co²⁺) and Ni²⁺ (TSNCS-Ni²⁺) was found to be 1:1 based on Job’s plot analysis. The results showed that the chemosensor TSNCS could provide a rapid analytical method for naked-eye detection of Co²⁺ and Ni²⁺ with detection limits (LOD) of 0.0114 μM and 0.0168 μM, respectively. Furthermore, the TSNCS-based test papers strips were successfully used for the rapid detection of Co²⁺ and Ni²⁺ ions in an aqueous solution. In addition, probe TSNCS was applied for the qualitative and quantitative analysis of Co²⁺ in the commercial vitamin B12 and real water samples.

GRAPHICAL ABSTRACT

KEYWORDS:

• Colorimetric chemosensor
• Schiff base receptor
• 4-phenylthiosemicarbazide
• Co²⁺ and Ni²⁺ ions
• vitamin B12

Acknowledgments

The authors are grateful to the Research Council of University of Guilan for financial support of this research work.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/10610278.2022.2085105