Electrochemical sensor for facile detection of trace luteolin based on thio-β-cyclodextrin functionalized graphene/gold nanoparticles hybrids

• Electrochemical sensor has been developed to detect trace amount of luteolin based on SH-β-CD-GNs/AuNPs.
• The nanocomposite integrates the unique properties of GNs/AuNPs and CDs.
• The method can be applied to detect luteolin in real sample.
• This approach is facile, sensitive and cost-efficient.

ABSTRACTIn this work, a simple and highly sensitive electrochemical method was developed to detect luteolin based on thio-β-cyclodextrin functionalized graphene/gold nanoparticles modified glassy carbon electrode (SH-β-CD-GNs/AuNPs/GCE). The peak currents of luteolin on the SH-β-CD-GNs/AuNPs/GCE can be greatly enhanced compared to the SH-β-CD-GNs/GCE and the bare GCE. It suggests that the nanocomposite not only shows the excellent electrical properties of GNs and AuNPs but also exhibits higher enrichment ability of cyclodextrins via the host-guest interaction between cyclodextrin and luteolin. At the SH-β-CD-GNs/AuNPs/GCE, the peak currents increased linearly with the concentration of luteolin in the range of 10.0 pM to 10.0 μM. The detection limit was estimated to be 3.3 pM (S/N = 3), which was more sensitive or comparable with the previous electrochemical sensors for luteolin detection. The analytical performance of this sensor has been evaluated for the detection of luteolin in human serum with satisfactory results. Furthermore, the method might open up a new possibility by using the nanohybrids to monitor other flavonoids which can form host–guest complexes with cyclodextrins.