Selective binding of Pb with manganese-terephthalic acid MOF/SWCNTs: Theoretical modeling, experimental study and electroanalytical application.

A nanocomposite of flake-shaped manganese-terephthalic acid MOF/single-walled carbon nanotubes (Mn(TPA)-SWCNTs) was synthesized using manganese chloride, terephthalic acid and SWCNTs as raw materials. Theoretical modeling study shows that the Mn(TPA) component has stronger adsorption ability to lead ion (Pb) than the other common heavy metal ions, which is in good agreement with the result of electrochemical assay. Then, the Mn(TPA)-SWCNTs were used as a sensing matrix for the voltammetric determination of Pb. The results displayed that the sensor shows high analytical performance for Pb due to the synergy of Mn(TPA) with highly selective binding to Pb and SWCNTs with high electronic conductivity. Under the optimal conditions, the Mn(TPA)-SWCNTs-based electrochemical sensor presented a wide linear response over the concentration range from 0.10 to 14.0μM. The limit of detection was achieved to be 38nM. Satisfactory results were also achieved when the Mn(TPA)-SWCNTs-based sensor was utilized for the determination of Pb in the practical samples of industrial wastewater and human serum, suggesting great promising of the sensor for practical application.