DETERMINATION OF SOME METAL-IONS USING LICHEN-MODIFIED CARBON PASTE ELECTRODES

Lichens have long been used as biomonitors of environmental pollution. We therefore investigated the application of lichen-modified carbon paste electrodes (CPEs) for the determination of lead(II) and copper(II) using differential pulse anodic stripping voltammetry. These electrochemical biosensors incorporate the biological selectivity of lichen species such as Cladonia portentosa and Lobaria pulmonaria, and the genus Roccella, with the sensitivity of electrochemical detection. As such, they may offer new reactivity patterns that could be exploited in the determination of trace metal ions in environmental samples and in speciation studies. The voltammetric responses were evaluated with respect to pH of accumulation (carried out under open circuit conditions), pH of electrolyte solution, metal ion concentration, percentage lichen loading in the carbon paste, interferences, and surface renewal.