Chiral Covalent Organic Frameworks for Enantioselective Sensing: Electrochemical, Electrochemiluminescence, and Photoelectrochemical Platforms

Chiral covalent organic frameworks (CCOFs) merge the structural versatility of covalent organic frameworks with chirality, offering a powerful platform for enantioselective electrochemical sensing. This review comprehensively summarizes recent advances in CCOF-based sensors, focusing on signal transduction mechanisms. Three primary synthetic strategies (direct synthesis, post-synthetic modification, and chiral induction) and four electrode immobilization approaches (drop-casting, in situ growth, membrane fabrication, and nanopipette modification) are outlined and critically assessed with respect to their advantages and limitations. Based on photon involvement, the sensing applications are categorized into three operational modes: pure electrochemical, electrochemiluminescence (ECL), and photoelectrochemical (PEC) sensing. For each mode, the design principles, analytical performance, recognition mechanisms, and structure–property relationships are discussed. Current challenges and future directions are examined, spanning from analyte scope expansion and mechanistic elucidation to conductivity enhancement, aqueous stability, fabrication–performance correlations, multi-mode synergistic platforms, and real-sample validation. This review provides a coherent framework for understanding CCOF-based enantioselective electrochemical sensing and perspectives for future development.