Facile synthesis of Co3O4/C porous polyhedrons for voltammetric determination of quercetin in human serum and urine

Due to the highly porous structure, metal organic framework (MOF)-derived materials are extensively applied in the field of electroanalysis. In this experiment, an effective electrochemical sensing based on Co 3 O 4 /C-derived ZIF-67 MOF had been constructed for ultrasensitive determination of quercetin at trace level. The resultant Co 3 O 4 /C porous polyhedron of morphology and nanostructure were carefully examined using transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Brunauer–Emmett–Teller (BET) techniques. Differential pulse anodic stripping voltammetry (DPV) method was adopted to analyze quercetin under the optimized conditions. The DPV response of Co 3 O 4 /C film-coated glass carbon electrode (Co 3 O 4 /C/GCE) for quercetin determination was achieved a long linearity ranging from 0.5 to 30 µM, achieving high sensitivity about 1.830 × 10 − 6  A cm − 2 µM − 1 , and the detection limit was calculated to be 0.022 µM (S/N = 3). Besides, the fabricated Co 3 O 4 /C/GCE displayed excellent selectivity, desirable repeatability, and good reproducibility. More importantly, the proposed sensor exhibited satisfactory recovery ranges and accuracy for the determination of trace quercetin in human urine and serum samples, which will make it as an alternative advantageous choice for practical on-site determination. Graphical abstract The porous Co 3 O 4 /C polyhedron derived by ZIF-67 MOF was successfully synthesized. The as-synthesized material was employed to prepare chemically modified electrode for ultrasensitive determination of quercetin. Then the Co 3 O 4 /C-modified glass carbon electrode is displayed good sensitivity and accuracy toward quercetin in urine and serum samples.