Artful union of a zirconium-porphyrin MOF/GO composite for fabricating an aptamer-based electrochemical sensor with superb detecting performance

摘要

More and more attentions have been focused on design and synthesis of novel metal-organic framework/graphene oxide(MOF/GO)composites with unique performance.Zirconium-porphyrin MOF(PCN-222)is in-situ synthesis with the existence of GO with-COOH group to artfully fabricate a PCN-222/GO composite.This composite can be employed as functional material to modify the working electrode.Thanks to excellent electrical conductivity of GO,abundant mesoporous channels and numerous Zr(Ⅳ)metal sites of PCN-222,this composite can immobilize a large amount of aptamer through strongπ-πstacking interaction and high affinity between phosphate group of aptamer and Zr(Ⅳ)site of PCN-222 simultaneously.Hence,an ultra-sensitive electrochemical aptasensor based on PCN-222/GO composite can quantificationally detect trace chloramphenicol with limit of detection of 7.04 pg/m L(21.79 pmol/L)from 0.01 ng/m L to 50 ng/m L by electrochemical impedance spectroscopy even in real samples.Meanwhile,this fabricated aptasensor reveals good repeatability,outstanding selectivity and preferable long-term storage.This research provides a useful approach to construct MOF/GO composites for fabricating electrochemical aptasensors in the electrochemical detection field.