Gas chromatographic/mass spectrometric profiling of luteolin and its metabolites in rat urine and bile

Although most of the composite based electrocatalysts for determination of luteolin has been developed, the unsatisfactory limit of detection (LOD) and narrow linear range originated from the unstable interface among each component limit their further application. Herein, a SnO2 quantum dots modified glass carbon electrode (SnO2 QDs/GCE) is developed for selective detection of luteolin. The electrochemical behavior of luteolin on SnO2 QDs/GCE indicates that the redox process involves participating of two-electrons/double-protons. The big specific surface area of SnO2 QDs provides sufficient active sites for the redox reaction of luteolin. On this bases, an ultra-low LOD of 0.25 nM as well as a large linear range of 0.1–1200 nM is obtained for detection of luteolin. Besides, the influence of several coexisting compounds and common ions on the detection of luteolin was evaluated, and no obvious interference was found. Finally, the SnO2 QDs/GCE electrode achieves accurate detection of luteolin in actual samples including orange, lemon and carrot juices. This work provides new strategy for the determination of luteolin in complex systems.