Facile synthesized SnO₂ decorated functionalized graphene modified electrode for sensitive determination of daidzein

A one-step and facile method using SnCl₂·H₂O as reducing agent to reduce graphene oxide (GO) was performed in the aid of poly(diallyldimethylammonium chloride) solution (PDDA). SnCl₂·H₂O is not only a reducing agent for graphene oxide (GO), but also a precursor of SnO₂. SnO₂-PDDA-GR composite was characterized by various surface, structural and electrochemical analysis techniques, such as transmission electron microscopy (TEM), UV spectrum (UV-vis), Infrared Spectrum (IR), X-ray diffraction (XRD), Cyclic voltammograms (CV) and electrochemical impedance (EIS). The SnO₂-PDDA-GR composite was used to constructed electrochemical sensor (SnO₂-PDDA-GR/GCE) for the determination of daidzein. Under the optimized experimental condition, it was found that the response of peak current is linear to the concentration of daidzein in the ranges of 2.0×10^-8 -1.0×10^-6molL^-1, and the detection limit was estimated to be 6.7×10^-9mol L^-1 (S/N=3). Furthermore, this sensor was successfully applied for the determination of daidzein in traditional Chinese medicine (pueraria lobata) and Daidzein tablets.