A selective colorimetric chemosensor for detection of Cu(II) ions in aqueous samples

Abstract

In this work we report a selective colorimetric chemosensor (S) for $\mathrm{Cu}^{2+}$ ion detection in aqueous media. It has been synthesized by a condensation reaction between 1-hydrazinophtalazine and 6,$6^{\prime}$-dihydroxy-5,$5^{\prime}$dimethoxy-(1,$1^{\prime}$-biphenyl)-3,$3^{\prime}$-dicarbaldehyde. The interaction between S and $\mathrm{Cu}^{2+}$ was studied and the results showed a bathochromic shift at 420 nm in UV–Vis spectra. The absorbance enhancement of S was attributed to complex formation with $\mathrm{Cu}^{2+}$ by 2:1 stoichiometry. The proposed analytical method can be applied to $\mathrm{Cu}^{2+}$ quantification with a linear range covering from 5.0 to $315.8~{\mu }$M, and can be used to routinely analyze $\mathrm{Cu}^{2+}$ in environmental aqueous samples with satisfactory results.

Keywords

• Colorimetric sensor
• $\mathrm{Cu}^{2+}$ detection
• Ion recognition
• DFT
• UV–Vis method