Octahedral Ce-MOF as an electrochemical sensor for the detection of chloramphenicol

Abstract

An efficient Ce-MOF@Aptamer electrochemical aptamer sensing technology has been established for the sensitive detection of chloramphenicol (CAP) in milk samples. The cerium-based metal–organic framework (Ce-MOF) was synthesized by using terephthalic acid as an organic ligand and cerium nitrate as the metal center. Subsequently, it was functionalized with EDC–NHS and covalently attached to the electrode, and the functionalized aptamer was loaded to form a sensing platform. The unique octahedral three-dimensional structure of Ce-MOF endows it with a large specific surface area and rich pore structure. The MOF structure itself and its metal center cerium may facilitate electron conduction during the electrochemical reaction process, thereby enhancing the electrochemical signal response. Compared with other metal MOFs, cerium, due to its potential activity in catalysis, oxidation–reduction and other aspects, can enable the future functional expansion of sensors (such as self-signal amplification). The minimum detection limit of the sensor is 0.7 nM. In addition, the sensor can effectively detect CAP in milk samples with excellent selectivity, repeatability and stability.