A pyrazole-based colorimetric chemosensor for selective arsenate detection in the presence of cyanide interference
- 1Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore 632014, Tamil Nadu, India
- 2Corresponding author.
Abstract
A simple pyrazole-based colorimetric chemosensor, 4( E )-1-(4-((2-(2,4-dinitrophenyl)hydrazinylidene)methyl)phenyl)-1H-pyrazole ( PY-09 ), was developed for the selective detection of arsenate (AsO 4 3− ) and cyanide (CN − ) ions through distinct optical responses. The free probe exhibited a yellow colour, which changed to magenta upon interaction with either AsO 4 3− or CN − , enabling rapid naked-eye detection. UV–Vis absorption studies revealed a bathochromic shift from 403 nm to 507 nm for AsO 4 3− and to 508 nm for CN − . The probe demonstrated high sensitivity, with detection limits of 0.99 μM for AsO 4 3− and 0.29 μM for CN − . Job's plot analysis indicated binding stoichiometries of 1:1 for both AsO 4 3− and CN − , while the corresponding association constants were determined to be 2.14 × 10 5 M −1 and 4.4 × 10 4 M −1 , respectively. The sensing process was reversible upon the addition of trifluoroacetic acid (TFA). Furthermore, hydrogen peroxide was successfully employed as a masking agent to selectively eliminate cyanide interference, enabling the specific detection of arsenate ions. The practical applicability of PY-09 was validated through successful analysis of real water samples, demonstrating excellent recovery and reliability. These findings highlight PY-09 as a simple, sensitive, and cost-effective colorimetric chemosensor, demonstrating its potential for colorimetric arsenate detection in water samples.
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BibTeX
@article{mithra2026pyrazolebased,
title = {{A pyrazole-based colorimetric chemosensor for selective arsenate detection in the presence of cyanide interference}},
author = {U. Mithra and V. Vijayakumar and S. Sarveswari},
journal = {Results in Chemistry},
year = {2026},
month = nov,
doi = {10.1016/j.rechem.2026.104052},
url = {https://doi.org/10.1016/j.rechem.2026.104052},
note = {CC BY},
}
RIS
TY - JOUR
TI - A pyrazole-based colorimetric chemosensor for selective arsenate detection in the presence of cyanide interference
AU - U. Mithra
AU - V. Vijayakumar
AU - S. Sarveswari
PY - 2026
DA - 2026/11/09
JO - Results in Chemistry
DO - 10.1016/j.rechem.2026.104052
UR - https://doi.org/10.1016/j.rechem.2026.104052
AB - A simple pyrazole-based colorimetric chemosensor, 4( E )-1-(4-((2-(2,4-dinitrophenyl)hydrazinylidene)methyl)phenyl)-1H-pyrazole ( PY-09 ), was developed for the selective detection of arsenate (AsO 4 3− ) and cyanide (CN − ) ions through distinct optical responses. The free probe exhibited a yellow colour, which changed to magenta upon interaction with either AsO 4 3− or CN − , enabling rapid naked-eye detection. UV–Vis absorption studies revealed a bathochromic shift from 403 nm to 507 nm for AsO 4 3− and to 508 nm for CN − . The probe demonstrated high sensitivity, with detection limits of 0.99 μM for AsO 4 3− and 0.29 μM for CN − . Job's plot analysis indicated binding stoichiometries of 1:1 for both AsO 4 3− and CN − , while the corresponding association constants were determined to be 2.14 × 10 5 M −1 and 4.4 × 10 4 M −1 , respectively. The sensing process was reversible upon the addition of trifluoroacetic acid (TFA). Furthermore, hydrogen peroxide was successfully employed as a masking agent to selectively eliminate cyanide interference, enabling the specific detection of arsenate ions. The practical applicability of PY-09 was validated through successful analysis of real water samples, demonstrating excellent recovery and reliability. These findings highlight PY-09 as a simple, sensitive, and cost-effective colorimetric chemosensor, demonstrating its potential for colorimetric arsenate detection in water samples.
SN - 2211-7156
ER -