Carbon-Based Electrochemical Sensors and Voltammetry for the Detection of Biologically Active Molecules: Fundamentals, Theoretical Aspects, and Emerging Perspectives

Electrochemical sensors offer a versatile and powerful platform for detecting biologically and electrochemically active molecules owing to their high sensitivity, selectivity, low cost, and rapid response. This review presents recent advancements in nonenzymatic electrochemical sensors based on carbon-based materials (CBMs), such as graphite, graphene, carbon nanotubes, nanofibers, quantum dots, aerogels, and fullerenes. Emphasis is placed on surface modification strategies using amino acids, surfactants, ionic liquids, and dyes to enhance electrocatalytic performance, antifouling properties, and molecular recognition capabilities. Fundamental voltammetric techniques are discussed alongside representative analytes, including dopamine, riboflavin, rutin, vanillin, amoxicillin, formoterol fumarate, catechol, and indigo carmine. Furthermore, the review addresses key challenges including signal overlap, biofouling, reproducibility, and a lack of standardization. Emerging directions, including AI-driven signal processing, wearable sensing platforms, quantum electrochemical modeling, and sustainable sensor design, are also highlighted. This review provides a comprehensive overview of electrochemical sensor fabrication, surface modification techniques, and the fundamentals and theoretical aspects of voltammetry, serving as a valuable resource for newcomers to the field.