Efficient simultaneous determination of baicalein and luteolin based on a carbon fiber paper electrode modified with CuO/ZnO-CCNT ternary nanocomposite.

In this paper, by a simple hydrothermal method vertically aligned ZnO nanorod arrays were grown on the carbon fiber paper (CFP) and then through a facile chemical bath deposition method CuO nanosheets were loaded on ZnO nanorod arrays, following by thermal spraying method, carboxylated carbon nanotubes (CCNTs) were successfully integrated with CuO/ZnO@CFP to form a binder-free CuO/ZnO-CCNT@CFP sensor. The sensor shows enhanced sensing activity for baicalein and luteolin determination due to the improved structural integration and synergism of different electrode material components. Remarkably, the CuO/ZnO-CCNT@CFP sensor showed good linear relationships over wide concentration ranges of 0.03–0.70 µM and 0.70–20 µM for baicalein and 0.03–0.45 µM and 0.45–8.5 µM for luteolin detection, with the detection limits of 1.7 nM for baicalein and 0.5 nM for luteolin, respectively. More importantly, the CuO/ZnO-CCNT@CFP sensor was utilized in the simultaneous determination of baicalein and luteolin, delivering linear ranges of 0.4–14 µM (baicalein) and 0.2–6 µM (luteolin) with the limit of detection of 0.05 µM and 0.03 µM, respectively. In addition, the developed CuO/ZnO-CCNT@CFP electrode was further investigated to detect baicalein and luteolin in traditional herbal medicine samples, showing satisfied results in comparison with analytic results from high performance liquid chromatography. [ABSTRACT FROM AUTHOR]