Nanocomposites Based on Polystyrene Sulfonate as Sensing Platforms. Comprehensive Electrochemical Study of Carbon Nanopowders and Carbon‐Nanofibers Composite Membranes

Nanocomposite membranes, prepared from carbon nano‐powders (CnP) or carbon nano‐fibers (CnF) dispersions in polystyrene sulfonate (PSS), were evaluated as sensing platforms. Composite surfaces were analyzed by scanning electron microscopy and field‐emission electron microscopy. Electrical and electrochemical properties of composite membranes were evaluated. Percolation threshold was reached at percentages higher than 5 % CnP or 0.5 % CnF. Best electrochemical responses were obtained on electrodes modified with composites containing 10 % CnP and 1 % CnF. Using a PSS‐10 % CnP composite modified electrode, a limit of detection of 0.3 µg L−1 (1 nM) was obtained in lead determination by differential pulse anodic stripping voltammetry.