3D RGO/MWCNTs-loaded bimetallic-organic gel derived ZrFeOx as an electrochemical sensor for simultaneous detection of dopamine and paracetamol

Abstract

In the current study, bimetallic-organic gel (ZrFe-MOGs) were rapidly prepared without using any toxic or harmful organic solvent, and new bimetallic oxide ZrFeOx were prepared by roasting ZrFe-MOGs directly. Then ZrFeOx nanoparticles were combined with 3D RGO/MWCNTs by a solvothermal method to synthesize 3D RGO/MWCNTs@ZrFeOx hybrid. Due to its three-dimensional structure, large electroactive surface area and more active sites, and excellent conductivity, the electrocatalytic activity of the modified electrode for the oxidation of dopamine (DA) and paracetamol (PAT) was effectively improved, and the overlap of anode peak due to their closer electrochemical oxidation potentials was solved. Under optimal conditions, the linear responses to DA and PAT were in the range of 1 − 12 μM, 12 − 180 μM and 1 − 14 μM, 14 − 190 μM, respectively. The detection limits (S/N = 3) for DA and PAT were 0.230 and 0.212 μM, respectively. The optimized 3D RGO/MWCNTs@ZrFeOx has good reproducibility, repeatability, stability, selectivity, and can be used to detect DA and PAT simultaneously. In addition, the proposed RGO/MWCNTs@ZrFeOx sensor exhibited a good recovery factor in the analysis of real drug and serum samples with a relative standard deviation of less than 5 %. Importantly, the electroactive area of 3D RGO/MWCNTs@ZrFeOx, and the 2 H+/2e- mechanism of DA and PAT oxidation on the surface of 3D RGO/MWCNTs@ZrFeOx were discussed, which provided a theoretical basis for further understanding of this redox process.