Mild and novel electrochemical preparation of β-cyclodextrin/graphene nanocomposite film for super-sensitive sensing of quercetin

A mild and novel preparation tactics based on electrochemical techniques for the fabrication of electro-deposited graphene (E-GR) and polymerized β-cyclodextrin (P-βCD) nanocomposite film were developed. The structure and morphology of GR-based nanocomposite were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. Simultaneously, the electrochemical properties of this nanocomposite were characterized by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Based on the synergistic effect of E-GR and P-βCD, a super-sensitive electrochemical sensor for quercetin was successfully fabricated. Under optimum conditions, the determination range for quercetin was from 0.005 to 20 µM with a low detection limit of 0.001 µM (S/N=3). Moreover, this sensor also displays excellent sensitivity, fine reproducibility and stability. To further study the practical applicability of the proposed sensor, the determination of real samples was carried out with satisfactory results.