Utilization of heat-dried Pseudomonas aeruginosa biomass for voltammetric determination of Pb(II)

In this research, thermally dried Pseudomonas aeruginosa cells were used as a biological material for the construction of a microbial biosensor. The preparation, optimization and application of the developed microbial biosensor, which analyzed Pb(II), are presented. The method was based on stripping of adsorbed metal ions from the modified electrode surface. Modified carbon paste electrodes were preconcentrated at open circuit, and then electrochemically measured by using cyclic voltammetry (CV) and differential pulse stripping voltammetry (DPSV) techniques. It was found that the thermally dried cells were capable of adsorbing Pb(II) ions from aqueous solutions and could determine the ions prominently at optimum experimental conditions. Many important parameters to acquire the best electrochemical response were carried out, including effect of different electrolyte solutions, pH, deposition potential, deposition time, ionic strength, preconcentration time, and effect of interference ions. Finally, a calibration graph was obtained with a linear range from 1.0×10(-6) to 2.0×10(-5) M Pb(II) (R(2)=0.9916) and detection limit was found as 6.0×10(-7) M Pb(II) by using 3×S(b)/m formula. Other analytical properties of the developed microbial biosensor were also investigated. The suggested usage format of P. aeruginosa for the determination of Pb(II) does not require complicated immobilization procedure, easy to handle, and not time consuming.