Evaluation of the Analytical Capabilities of Some Bacterial and Hybrid Sensors for Environmental Pollutants Determination

Some bacterial and hybrid (bacterial/enzymatic) electrochemical sensors were evaluated for potential in situ metal ions and organophosphorus pesticides determinations. The analytical performances of the Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans based sensors for ferrous iron and of the Arthrobacter globiformis/acetylcholinesterase based one for chlorofos quantification were estimated throughout comparative studies. It was found that the two Fe2+ sensors provide better LOD (0.9 μmol L-1 and 2.4 μmol L-1 respectively) than that developed by Mandl et al. (60 μmol L-1) earlier. The hybrid (bacterial/enzymatic) sensor for chlorofos provides the same LOD but much longer lifetime at ambient temperature than the enzymatic ones. Reproducibility and high detection sensitivity of the determinations were achieved applying an original bacteria immobilization strategy, improved transducer design, and noise suppression technique.