Ce-MOF/COF/carbon nanotube hybrid composite: Construction of efficient electrochemical immune platform for amplifying detection performance of CA125

The combination of metal organic framework (MOF), covalent organic frameworks (COF) and carbon nanotube (CNT) forms a system due to their synergistic effect, thereby possessing the structural traits of individual components and exhibiting new properties. Herein, we successfully integrated terephthalonitrile-based-COF (TPN-COF)/CNT into the Ce-MOF, designed and synthesized Ce-MOF/TPN-COF/CNT hybrid material to construct a label-free immunosensor for specific detection of carcinomicantigen 125 (CA125). The synthesized composite exhibited abundant active sites and excellent electronic conductivity. As a result, more immunocomplex were immobilized to the carbon paste electrode (CPE) modified by Ce-MOF/TPN-COF/CNT owing to the hydrogen bonding and π-π interaction between triazine ring and trimesic acid ligand, leading to produce an amplified current response. The results of various instrument tests demonstrated that these structural advantages indeed contribute to the low detection limit of 0.000088 U/mL and wide linear range from 0.0001 U/mL to 100 U/mL for the CA125 immunosensor, which was superior to those of other proposed immunosensor. In addition, the constructed CA125 immunosensor exhibits good stability, repeatability, specificity, regeneration characteristics and acceptability in human serum. Therefore, MOF/COF/CNT composite holds promise as an electrode platform for building electrochemical immunosensors in the early diagnosis of cancer.