Co@IRMOF-9/GCE sensor for rapid electrochemical identification of trace Hg2+, Pb2+ and NO2− in solutions

Abstract

Simultaneous trace detection of many toxic metal ions is a difficult and valuable problem. In this paper, we have designed and constructed an innovative electrochemical sensor for synchronously detected trace amounts of Hg2+, Pb2+ and NO2− in solution quickly, accurately and at low cost. In this study, IRMOF-9 was modified by solvothermal method to prepare Co@IRMOF-9 as electrode material. Co2+ as the active ingredient, IRMOF-9 with ideal specific surface area and porosity, and the synergistic interaction between the Co2+ and IRMOF-9 enhances the electrochemical sensing performance of Co@IRMOF-9. The structure, composition, electrochemical sensor identification performance and practical application characterization of Co@IRMOF-9 prove that this novelty sensor platform has the feature of reliability and sensitivity. The Co@IRMOF-9/GCE sensor can identify Hg2+, Pb2+ and NO2− only in 200 s in the solution concentration range of 0.04–10 μM, 0.05–100 μM, 0.05–100 μM with the LOD, is 1.33 nM, 1.66 nM, and 1.27 nM, respectively. This paper provides a strategy and method for designing a simple and practical electrochemical sensor platform that can in real time identify multiple harmful trace metal ions in solution.