Novel UIO-66-NO2@XC-72 nanohybrid as an electrode material for simultaneous detection of ascorbic acid, dopamine and uric acid

Abstract

UIO-66-NO₂@XC-72 nanohybrid was synthesized from UIO-66-NO₂ via hydrothermal synthesis method, followed by mixing with XC-72 carbon (XC-72). The compositions, microstructures, textural parameters and morphologies of the resulting nanomaterials were characterized by FTIR, XRD, N₂ adsorption–desorption, SEM and TEM. The UIO-66-NO₂@XC-72-modified glassy carbon electrode (GCE) sensor was successfully applied to the simultaneous determination of ascorbic acid (AA), dopamine (DA) and uric acid (UA). Owing to the large surface area of UIO-66-NO₂ and good conductivity of XC-72, as well as the hydrogen bond effect between the UIO-66-NO₂ and the analyte, the proposed sensor exhibited excellent linear responses to AA, DA and UA under optimized conditions. The detection ranges were 0.2–3.5 μM for AA, 0.03–2.0 μM for DA and 0.75–22 μM for UA, with the detection limits (S/N = 3) of 0.12 μM, 0.005 μM and 0.03 μM, respectively. Moreover, the high reproducibility and stability of the sensor were obtained in all the experiments. The sensor was also successfully applied to the determination of DA in hydrochloride injection solution and UA in urine sample. The MOFs@XC-72 would be potentially applied as a modified electrode sensor material for the determination of other small biomolecules.