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 Pb(2+) 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 Pb(2+) in concentration range from 5x10(-6) to 4x10(-4)molL(-1) in PVC film and 5x10(-6) to 3x10(-4)molL(-1) in ethanol medium, with a working pH 7. The detection limit was 2x10(-8) and 4x10(-8)molL(-1) for Pb(2+) in PVC film and ethanol medium respectively. The response time of Pb(2+) was found as 4min for PVC film and 2min for ethanol medium. The sensor developed in two different mediums was used for lead determination in standard soil sample with satisfactory results.