Sensitive electrochemical detection of rutin and isoquercitrin based on SH-β-cyclodextrin functionalized...

In this study, a sensitive electrochemical method based on thio-β-cyclodextrin functionalized graphene/palladium nanoparticles (SH-β-CD-Gr/PdNPs) was developed to detect rutin and isoquercitrin, respectively. The obtained SH-β-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-β-CD and PdNPs were successfully deposited on the surface of graphene nanosheets (GNs). The peak currents of rutin and isoquercitrin on the SH-β-CD-Gr/PdNPs modified glassy carbon electrode (GCE) are dramatically increased compared with that on the bare GCE and SH-β-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-β-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 1.0×10^-9-3.0×10^-5molL^-1 and 5.0×10^-12-5.0×10^-6molL^-1, with low detection limits of 3.0×10^-10molL^-1 and 1.6×10^-12molL^-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.