Sensitive electrochemical detection of rutin and isoquercitrin based on SH-β-cyclodextrin functionalized graphene-palladium nanoparticles

In this study, a sensitive electrochemical method based on thio-beta-cyclodextrin functionalized graphene/palladium nanoparticles (SH-beta-CD-Gr/PdNPs) was developed to detect rutin and isoquercitrin, respectively. The obtained SH-beta-CD-Gr/PdNPs were characterized by UV-vis spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. The results confirm that SH-beta-CD and PdNPs were successfully deposited on the surface of graphene nanosheets (GNs). The peak currents of rutin and isoquercitrin on the SH-beta-CD-Gr/PdNPs modified glassy carbon electrode (GCE) are dramatically increased compared with that on the bare GCE and SH-beta-CD-Gr/GCE. It indicated that the nanocomposite integrated the excellent electric conductivity and electrocatalytic activity of graphene and PdNPs, as well as the host -guest recognition and enrichment ability of SH-beta-CD. Under optimum conditions, differential pulse voltammetry (DPV) was used to measure the peak currents of the two drugs. The linear response ranges for rutin and isoquercitrin are 1.0 x 10(-9) -3.0 x 10(-9) mol L-1 and 5.0 x 10(-12) -5.0 x 10(-6) mol L-1, with low detection limits of 3.0 x 10(-19) mol L-1 and 1.6 x 10(-12) mol L-1, respectively. The proposed method might offer a new possibility for electrochemical analysis of rutin and isoquercitrin in pharmaceuticals or human serum owing to its low cost, simplicity, high sensitivity and good stability. (C) 2016 Elsevier B.V. All rights reserved.