Non-enzymatic xanthine sensor of heteropolyacids doped ferrocene and reduced graphene oxide via one-step electrodeposition combined with layer-by-layer self-assembly technology

Abstract

Heteropolyacids (PMo6W6) and ferrocene (Fc) were assembled on the glassy carbon electrode for the first time by electrodepositon method, and further combined with reduced graphene oxide (RGO) through the layer-by-layer self-assembly technology, developing a novel non-enzymatic nanocomposite for xanthine (XA) detection. The detection signal of XA was greatly amplified on the Fc-PMo6W6/RGO nanocomposite modified electrode due to coexist of these three active components. As ferrocene and PMo6W6 all have relatively good electrochemical reversibility, fast electron transfer ability and generation of stable redox forms, meanwhile RGO can enlarge the active surface area of the electrode, increase the conductivity and load of ferrocene and PMo6W6. Under the optimized conditions, the developed nanocomposite modified electrode displayed superb sensing property towards xanthine with a widely linear range from 5.00 × 10−8 ∼ 2.03 × 10-3 M, along with a relatively low detection limit of 1.01 × 10-8 M. The modified electrode has good stability as it is prepared by the smart combination electrodeposition and layer-by-layer self-assembly. Additionally, the nanocomposite was applied in detecting xanthine in actual samples with acceptable results, demonstrating the feasibility of Fc-PMo6W6/RGO nanocomposite in routine testing xanthine to some extent.