Advanced electrochemical biosensing exploiting mussel-inspired polydopamine interfaces

This review comprehensively examines the burgeoning field of electrochemical biosensors enhanced by mussel-inspired polydopamine (PDA) interfaces. PDA, derived from the oxidative self-polymerization of dopamine, offers remarkable substrate-independent adhesion, versatile chemical reactivity via catechol and amine groups, and inherent biocompatibility, making it an attractive material for surface functionalization in biosensing. We delve into the fundamental aspects of PDA synthesis pathways and the resulting physicochemical properties crucial for electrode modification, including adhesion mechanisms, film formation control, functional group availability, and electrochemical characteristics. Diverse strategies for engineering PDA interfaces on electrode surfaces are systematically reviewed, encompassing direct coating, composite formation with various nanomaterials such as graphene, carbon nanotubes, and metal/metal oxide nanoparticles, layer-by-layer assembly, and controlled electropolymerization. The review categorizes and critically analyzes the wide array of applications reported for PDA-based electrochemical biosensors, focusing on the detection of key analytes such as disease biomarkers, pathogens, neurotransmitters, small molecules, and environmental toxins. Performance metrics, including sensitivity, selectivity, limit of detection, and stability, are discussed in relation to the advantages conferred by the PDA interface. Finally, current challenges, such as optimizing PDA conductivity and long-term stability, and future perspectives, including the development of multiplexed platforms and potential in vivo applications, are addressed.