A highly selective colorimetric chemosensor for detection of iodide ions in aqueous solution

Abstract

We synthesized a new iodide ion (I⁻) chemosensor (CS) based on a hydrazone derivative obtained from the condensation of 2-hydroxy-1-naphthaldehyde and 2,4-dinitrophenylhydrazine. The CS showed selective colorimetric recognition of I⁻, the miscellaneous competitive anions (F⁻, Cl⁻, Br⁻, HSO₄⁻, CH₃COO⁻, H₂PO₄⁻, SCN⁻, CN⁻, ClO₄⁻ and S⁻) did not lead to any significant interference. The detection limits of the CS for I⁻ is 1.1 × 10⁻⁶ M. The sensor has been successfully applied to estimate the content of iodide ions in urine. Moreover, ion test strips based on CS were fabricated, which could act as a convenient and efficient I⁻ test kit for “in-the-field” measurement of iodide ions.