A biosensor based on fungal soil biomass for electrochemical detection of lead (II) and cadmium (II) by differential pulse anodic stripping voltammetry

A sensitive voltammetric method for detection of trace heavy metal ions using a glassy carbon electrode surfaces chemically modified by a mixture of (SWCNTs/Biomass) was applied. The fungus is used as an inactive biomass, which was selected from soil contaminated with metals. The cell walls have a large number of chemical groups such as carboxyl, sulfonate, amine, hydroxyl, carbonyl and imidazole with which may affect and intervene in the fixing of metal ions. In this assay, heavy metals ions accumulated on the GCE/SWCNTs/Biomass electrode surfaces prior to being subjected to differential pulse anodic stripping voltammetry analysis (DPASV). The resulting peak currents were linearly related to the concentrations of the metal ions. The method was optimized with respect to accumulation time, reduction time and reduction potential. The detection limits were found to be 10(-8)M and 10(-7)M for Pb2+ and Cd2+ respectively.