Advancing Targeted Functionalization of Metal–Organic Frameworks for the Design of Electrochemical Sensors

The present work explores the use of proton‐conducting metal–organic frameworks (MOFs), functionalized with selected chemical groups (fMOFs), for the development of electrochemical sensors. The introduced functionalization aimed to improve the homogeneity of sensor composites containing electron‐conducting components—multiwalled carbon nanotubes and/or gold nanoparticles (AuNPs)—thereby ensuring uniform proton–electron transport and enhancing the material's affinity toward analyte molecules. Owing to the strong interaction between AuNPs and sulfur‐based functionalities, the magnesium‐based CPO‐27 (MOF‐74) framework was modified with thiocyanate (NCS ‐ ) groups. To assess the effect of analyte‐tailored functionalization aimed at the biogenic amine tyramine, the sulfonated framework JUK‐14 was used, as –SO 3 ‐ groups exhibit strong affinity toward amino functionalities, and compared with its nonsulfonated counterpart, UCY‐14. Overall, this study demonstrates the strong potential of functionalized metal–organic frameworks to enhance the analytical performance of electrochemical sensors.