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

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 strong pi-pi stacking 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/mL (21.79 pmol/L) from 0.01 ng/mL to 50 ng/mL 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. (C) 2021 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.