Bio-modified carbon paste electrode for the detection of Pb(II) ions in wastewater

Heavy metal pollution in water is a serious environmental concern. Lead is one of the highly toxic heavy metals, and its toxicity is due to its non-degradation characteristic in living organisms. The monitoring of Pb(II) ions concentrations in drinking water is essential for human health and a safe environment. In this work, bio-modified carbon paste electrodes were constructed with live cells and thermally dried biomass (extracted protein) from Pseudomonas aeruginosa cells and employed for the detection of Pb(II) ions from wastewater. The biomass and biosensor preparation and optimization, and the performance of modified biosensors in the detection of Pb(II) ions are discussed here. The effect of various parameters, like pH, biomass composition, scan rate, and metal ion concentration, were studied to obtain the best electrochemical response. Further, the active surface of the electrode and solution characteristics were studies using chronocoulometry and electrochemical impedance spectroscopy. Fourier transform infrared spectroscopy (FTIR) analysis was done to find the functional groups present in the thermally dried biomass. From the present study, it is clear that the thermally dried protein biomass electrode has more sensitivity than the bare carbon paste electrode.