A heterometallic sensor based on Ce@Zn-MOF for electrochemical recognition of uric acid

Abstract

A novel nanoflower microsphere Zn-MOF has been solvothermally synthesized. By virtue of the large porosity and specific surface area of Zn-MOF, Ce salts have been successfully incorporated into the cavity of Zn-MOF to fabricate bimetallic Ce@Zn-MOF composites, which were covered in glassy carbon electrode (GCE) as sensors for the efficient recognition of uric acid (UA). The electrochemical behaviors of Zn-MOF and Ce@Zn-MOF-based sensor for UA were analyzed by cyclic voltammetry (CV) and differential pulse stripping voltammetry (DPV). The results showed that the Ce@Zn-MOF/GCE-based sensor exhibited sensitive identification ability for UA in phosphate buffered saline (PBS) solution (pH = 7.0) with a low detection limit (DL) of 0.51 ng in the recognition range of 0–300 ng mL −1 . The results were attributed to that the introduction of Ce ions improved the charge conduction ability of Ce@Zn-MOF, thus enhancing the recognition sensitivity of Ce@Zn-MOF for UA, which can also be verified by theoretical calculation. In addition, Ce@Zn-MOF showed good stability, which can be ascribed to the bonding interaction between Ce ions and C/O atoms in Zn-MOF. Meanwhile, the Ce@Zn-MOF based sensor also exhibited high reproducibility and anti-interference ability for recognition of UA. In this work, the reasonable design of Ce@Zn-MOF based sensor provides a suitable platform for UA sensing rapidly and sensitively. • A novel nanoflower microsphere Zn-MOF with the BET value of 568 cm 3 /g has been synthesized under solvothermal methods. • Ce salts have been successfully encapsulated into the cavities of Zn-MOF to fabricate heterometallic Ce@Zn-MOF composites. • A heterometallic sensor based on Ce@Zn-MOF exhibited excellent electrochemical recognition for uric acid in PBS (PH = 7).