Triple Synergistic Antifouling Conductive MOFs via Cathodic Electrodeposition for Electrochemical Sensor

Electrochemical sensors face severe protein biofouling in complex biological matrices. Traditional antifouling coatings struggle to balance sensitivity with antifouling performance, as it is difficult to simultaneously achieve high conductivity and good hydrophilicity. Two-dimensional conductive metal-organic frameworks (2D c-MOFs), combining intrinsic electrical conductivity, inherent porosity, chemical tunability, and facile functionalization, offer an ideal material platform to resolve this dilemma. Herein, a hydrogen peroxide-mediated cathodic electrodeposition strategy enables in situ growth of a pure-phase, conductive Cu-HHTP (HHTP = 2,3,6,7,10,11-hexahydroxytriphenylene) MOF film by suppressing copper deposition and promoting ligand deprotonation. The Cu-HHTP MOF electrode features a triple synergistic antifouling mechanism comprising a superhydrophilic hydration barrier, molecular sieving, and electrostatic repulsion, achieving good antifouling capabilities with a current retention exceeding 90% after protein fouling. For uric acid (UA) sensing, the electrode exhibits high sensitivity (1.30 μA cm-2 μM-1), a low detection limit (52 nM), and good selectivity. This work provides a simple and universal strategy for constructing high-performance antifouling electrochemical sensing interfaces.