Recent advancements in covalent organic frameworks as electrochemical and spectroscopic biosensors

Over the last twenty years, covalent organic frameworks (COFs) have emerged as a significant class of porous materials, garnering considerable attention due to their broad applicability in catalysis, separation processes, and energy storage. Their high specific surface area and tunable structural features facilitate the effective immobilization of diverse biomolecules, such as enzymes, aptamers, DNA, and antibodies, thereby enhancing the functionality of electrochemical and spectroscopic biosensing platforms. Extensive investigations have demonstrated that COFs can host substantial amounts of probes while preserving excellent biocompatibility and markedly improving stability. These attributes position COFs as highly promising candidates for biosensing applications that require elevated selectivity and sensitivity. This comprehensive review critically evaluates recent progress in COF-based electrochemical and spectroscopic biosensors, emphasizing various modification methodologies and target analytes. Additionally, it addresses the principal challenges and future directions for the expanded utilization of COFs in biosensing.