A hydrazine-based thiocarbamide probe for colorimetric and turn-on fluorometric detection of PO43− and AsO33− in semi-aqueous medium

Abstract

2,6-Bis(N-ethylhydrazonethiocarbamide)-4-methyl-phenol (HTP) recognizes PO₄³⁻ and AsO₃³⁻ and is effective as a colorimetric and turn-on fluoremetric sensor in the presence of a large number of biologically important cations and anions. The limit of detection (LOD) is 34 nM for PO₄³⁻ and 15 nM for AsO₃³⁻. The composition of the probe–anion association has been established by Job's plot, ¹H-NMR titration and HR-MS data. The Density Functional Theory (DFT) computation technique is used to optimize the structure that has been compared with an X-ray structure of HTP and the calculated electronic properties are correlated with the experimental results. Turn-on detection of PO₄³⁻ and AsO₃³⁻ is also successfully utilized for the fabrication of an ‘OR’ gate. The probe, HTP, is used for analysis of the ground water of Jadavpur, Kolkata.