Conductive Nanocomposites for Electrochemical Sensing of Environmental and Biological Contaminants

Supramolecular nanocomposite materials rely on intermolecular interactions to create dynamic, responsive systems for electrochemical sensing. This work explores two biological applications of distinct external stimuli that activate nanocomposite systems to achieve tailored functionality. The first case study explores biopolymeric hydrogels (i.e., alginate and cellulose) that were functionalized via metal-coordination assisted photopolymerization of conductive polymers (i.e., aniline and pyrrole) and coated with bio-modified nanoparticles (IgG-TiO2). The antigen specific binding to the antibody enabled the sensing of target molecules, detected through surface impedance, allowing also for critical concentration analysis. The second case study examines conductive polysaccharide-based nanocomposites (i.e., alginate, pectin, agar) engineered to enhance electron transfer in microbial fuel cells. Metal-carboxyl coordination chemistry enabled the photo-polymerization of polyaniline (PANI) within the polymer matrix, while biofunctionalized TiO₂ nanoparticles facilitated bacterial adhesion, resulting in improved current flow and increased open circuit potential in the presence of light. Together, these studies demonstrate the versatility of nanocomposite design in biosensing and energy applications, highlighting their potential for tunable, stimulus-responsive electrochemical systems.