Application of metal-organic framework as redox probe in an electrochemical aptasensor for sensitive detection of...

In this work, an electrochemical aptasensor was developed for sensitive detection of MUC1 based on metal-organic framework-reduced graphene oxide nanocomposite (Cu-MOF-RGO). Cu- MOF-RGO appeared to be suitable as a platform for immobilization of MUC1 aptamer, and also as an electrochemical probe, which exhibited well-defined peaks with good stability and reproducibility. Cu-MOF-graphene oxide (Cu-MOF-GO) nanocomposite was prepared and cast on the electrode surface, then in order to increase the conductivity of the electrode, GO was electrochemically reduced to RGO. In the presence of MUC1, the peak current of Cu in the nanocomposite decreased, which could be explained based on the formation of MUC1-aptamer complexes on the electrode, and consequence blocking the electron transfer of Cu at the electrode surface. Under optimum experimental conditions, a linear calibration curve was obtained by differential pulse voltammetry in the concentration range of 0.1 pM-10 nM (25 pg mL^-1 - 2500 ng mL^-1) with a limit of detection (LOD) of 0.033 pM (7.5 pg mL^-1) of MUC1. The proposed aptasensor offers acceptable selectivity, stability, and reproducibility in the determination of MUC1 spiked to human blood serum samples.