A free-standing poly-MOF film fabricated by post-modification and interfacial polymerization: A novel platform for Cd2+ electrochemical sensors

Abstract Cd2+ sensors play an essential role in biology and environment. We adopted the post-modification and interfacial polymerization strategies to realize a free-standing and homogeneous filmy Cd2+ electrochemical sensor by copolymerizing MOF-867 nanocrystals with pyrrole monomers. This hybrid film exhibited good structural integrity and retained Cd2+ sensing behavior with good conductivity in a covalent film form. This poly-MOF hybrid film exhibited a highly excellent sensing selectivity and sensitivity for Cd2+ with a very low detection limit around 0.29 μg L−1, lower than pure MOF-867 and significantly below the standard for Cd2+ in drinking water, which benefited from the devisable architectures of MOF-867 with the good conductivity of PPy polymer matrix. This work highlighted a simple strategy for poly-MOF film formation and accelerated the MOFs-based materials for Cd2+ electrochemical sensing in practical applications.