Heteroatom-Rich Carbon Nanomaterials from Conjugated Polymers for Electrochemical Sensors

Tunable conductivity, heteroatom-rich composition, controllable morphology, and strong interfacial activity have resulted in carbon nanomaterials emerging as promising electrode modifiers for electrochemical sensors. As sources of sp2-rich carbon nanomaterials, conjugated polymers can be transformed through simple carbonization into carbon frameworks. Among them, polypyrrole- and polyaniline-derived carbon nanomaterials have been widely investigated for electrochemical sensing applications. In contrast, carbon nanomaterials derived from poly (3,4–ethylenedioxythiophene) have received comparatively limited attention, possibly due to the relatively high cost and established electrical conductivity of the polymer chain itself. The heteroatoms originally present in these polymers can be retained or transformed into active sites to promote electron transfer, analyte adsorption, and catalytic signal generation. This review summarizes recent progress in conjugated-polymer-derived carbon nanomaterials for electrochemical sensor applications, emphasizing precursor chemistry, morphology control, surface chemical regulation, metal and inorganic decoration, and sensing mechanisms. By clarifying the relationships among precursor structure, carbon framework, surface functionality, and electrochemical performance, this review offers guidance for designing sensitive and stable carbon-based sensing platforms.