New optical sensor based on the immobilization of a triazene ligand in PVC membrane for Hg(II) ion

Abstract

This paper describes the development and creation of a new sensitive optical sensor that is quite selective to Hg(II) ions in aqueous solution. The sensing element, the newly synthesized methyl 2-[3-(3-methylphenyl)-2-triazen- 1-yl]benzoate, incorporated into a plasticized poly(vinyl chloride) membrane, is able to determine Hg(II) ion with a high selectivity over a wide dynamic range from 5.0?115.1 ?g L-1 at pH 7.5 with a lower detection limit of 0.67 ?g L-1. The response of the optode membrane to Hg(II) was fully reversible and revealed a very good selectivity towards Hg(II) ion from a wide variety of other metal ions in solution. The overall performance characteristics of the sensor were evaluated and good reversibility, wide dynamic range, long life span, long-term response stability and high reproducibility were found. The proposed optical sensor gives proper results in applications including direct determination of the Hg(II) ion in real environmental samples.