A Highly Selective Luminescent Sensor for Detecting Mercuric Ions in Water

Abstract

A chemoluminescent sensor utilizing the substrate 2,6-pyridinedicarboxaldehydebis(o-hydroxyphenylimine) (S1) was developed for low-concentration detection of mercuric ions in aqueous solutions. The sensor selectively detects mercury in the presence of sodium, calcium, magnesium, and iron ions. A strong binding was observed between the mercuric ions and the substrate at a pH range of 6.5–7.5, which makes the substrate a distinctive luminescence sensor for detecting mercury at ambient conditions. The sensor shows a linear response towards Hg2+ in the concentration range 5.0 × 10–5 to 2.5 × 10–8 M with a limit of detection of 5.0 × 10–8 M. The sensor can also detect zinc ions at a pH of 10 or higher. The results indicate that this sensor has a promising future for the detection of mercury in real environmental water samples.