One-pot synthesis of cerium-organic framework@carbon black composites for simultaneous detection of dopamine, uric acid, and acetaminophen

Accurate identification of dopamine (DA), uric acid (UA), and acetaminophen (APAP) is critical to safeguarding human health. However, their simultaneous detection is still challenging due to their similar oxidation potentials. In this work, a series of new composites based on cerium-organic framework (Ce-MOF) and carbon black (CB) were constructed by one-pot method at room temperature. The introduction of CB can significantly affect the conductivity and specific surface area of the composites. The optimal composite Ce-MOF-COOH/CB0.4 can identify DA, UA, and APAP simultaneously with low detection limit of 0.030, 0.045, and 0.057 μM and wide detection range of 2.5–310.0, 3.0–305.0, and 2.5–617.0 μM, respectively. Furthermore, density-functional theory (DFT) calculation was performed to explore the influence of functional groups (-NH2 or –COOH) on the sensing performance. It was found that the introduced functional groups can obviously enhance the host-guest interactions through the formation of strong hydrogen bonds, which is beneficial for promoting sensing performance. In addition, the constructed electrode could also detect DA, UA, and APAP in real samples, which indicated its potential for practical applications. This study provides a feasible approach to utilize MOFs as electrochemical sensors for simultaneously detection of biomolecules.