Fungi-derived Chitosan-CTAB composite-based electrode for electrochemical simultaneous detection of Cd (II) and Pb...

Organic polymers have found diverse applications in the industrial and scientific world. One such application is using chitosan-based electrochemical sensors, which have gained rapid popularity due to their unique properties. To further enhance the material's porosity and adsorption capacity, the incorporation of a surfactant into the film has been explored. This study focuses on a rarely investigated combination of fungi-derived chitosan and cationic surfactant N-Cetyl-N, N, N-trimethyl-ammonium bromide (CTAB). The resultant composite was transformed into a thin film on the surface of a graphite electrode, by drop casting method, followed by curing at 65 °C hot air. The low-cost sensor thus obtained was characterized by electrochemical studies, and surface study techniques including AFM, SEM, and XPS. The results showed the properties of the film were strongly governed by the ratio of components in the composite. Under optimal conditions, the affinity for composite film increased 3 to 4 folds for Pb and Cd. The developed electrochemical sensors had a limit of detection of 0.317 μM and 0.572 μM for Pb and Cd respectively. The linear range of detection was found to be 1 × 10^-6 M to 1.2 × 10^-4 M for Pb (II) and 2 × 10^-6 M to 1.4 × 10^-4 M for Cd (II).