Fluorescence-based sensor for Pb(II) using tetra-(3-bromo-4-hydroxyphenyl)porphyrin in liquid and immobilized medium

A new optical sensor for sensing of Pb2+ in immobilized medium (PVC film) and ethanol medium was developed by using 5,10,15,20-tetra-(3-bromo-4-hydroxyphenyl)porphyrin (TBHPP) synthesized. The sensor-based TBHPP showed a linear response towards Pb2+ in concentration range from 5 × 10−6 to 4 × 10−4 mol L−1 in PVC film and 5 × 10−6 to 3 × 10−4 mol L−1 in ethanol medium, with a working pH 7. The detection limit was 2 × 10−8 and 4 × 10−8 mol L−1 for Pb2+ in PVC film and ethanol medium respectively. The response time of Pb2+ was found as 4 min for PVC film and 2 min for ethanol medium. The sensor developed in two different mediums was used for lead determination in standard soil sample with satisfactory results.