1.Electrochemical behavior of luteolin on a chitosan–graphene modified glassy carbon electrode and its sensitive detection
Guangjiu Li,* Lihua Liu, Yong Cheng, Shixing Gong, Xiuli Wang, Xiujuan Geng and Wei Sun*. Anal. Methods, 2014, 6, 9354–9360
In this paper a CS–GR-modified GCE was fabricated and applied to the investigation of the electrochemical behavior of luteolin. Under the selected conditions a pair of well-defined redox peaks appeared on the cyclic voltammograms, and the presence of GR resulted in the increase of the redox peak currents due to its large surface area which adsorbed more luteolin on the electrode surface. A sensitive differential pulse voltammetric method was further established for luteolin and drug sample detection, with satisfactory results.
2.Electrochemical determination of luteolin in Chrysanthemum using multi-walled carbon nanotubes–ionic liquid composite electrode
Jing Tang and Baokang Jin*. Anal. Methods, 2015, 7, 894–900
Although no obvious differences in the peak potential of luteolin can be observed at the GCE and modied electrodes, the redox peak currents of luteolin on the BMIMPF6/GCE, MWCNTs/GCE and MWCNTs–BMIMPF6/GCE were stronger than that on the bare GCE. The peak current at the MWCNTs–BMIMPF6/GCE was 3.99 mA, which was nearly 18-fold larger than that at the bare GCE (0.21 mA). These results mean that both MWCNTs and BMIMPF6 were electrocatalytically active toward luteolin, and the integration of the MWCNTs and BMIMPF6 provided a remarkable synergistic promotion for the increasing electrochemistry signals of luteolin, which could be attributed to the good conductivity of the IL. The MWCNTs–BMIMPF6 composite film promoted the electrochemical reaction of luteolin more efficiently. The electrode reaction mechanism of the electrooxidation of luteolin on the MWCNTs–BMIMPF6/GCE is shown in Scheme 1. The electrochemical oxidation of luteolin follows a two-electron and two-proton mechanism at the MWCNTs–BMIMPF6/GCE.
3.Spectroscopic and electrochemical studies on the evaluation of the radical scavenging activities of luteolin by chelating iron
Ai-Hong Yang,* Xue-Ying Shi. RSC Adv., 2014, 4, 25227–25233
Luteolin is a common flavonoid with biological effects such as antioxidant, anti-inflammation, antiallergic, anticancer and neuroprotective activities. It possesses two metal ions chelating sites: the 30,40-dihydroxy group in ring B and the 5-hydroxy and 4-carbonyl group in ring C (Scheme 1), which is predicted to chelate iron and then scavenge free radicals. However, up to now, there are few studies on antioxidant
effect about Fe(III) and luteolin, except for some spectro scopic and anti-inammatory studies about other metal complexes of luteolin.
4.Nickel clusters grown on three-dimensional graphene oxide–multi-wall carbon nanotubes as an electrochemical sensing platform for luteolin at the picomolar level
Taotao Yang, Yansha Gao. RSC Adv., 2015, 5, 64739–64748
SEM results indicate that substrates material has an important effect on the Ni morphology. It is supposed that the substrates material might affect the electrocatalytic activity of Ni-based materials, then the electrocatalytic activity of different dimensions carbon materials toward luteolin was investigated. As can be observed from Fig. 4A, when 100 mM luteolin was added into pH 3.0 PBS, luteolin showed poor redox current peaks at the bare GCE (a) and GO/GCE (b) within the potential window from 0 to 0.80 V, which might be due to the sluggish electron transfer of bare GCE and poor conductivity of GO. Larger oxidation peak current can be observed on GR/GCE (c) and MWCNTs/GCE (d), ascribing to the excellent electrical conductivity and large surface area properties of GR and MWCNTs. Compared with the 2D GO/GCE, GR/GCE and 1D MWCNTs/GCE, the redox peak currents show a remarkable increase on the 3D GO–MWCNTs/GCE (e).