Non-enzymatic glucose oxidation to gluconic acid with N, N′-bis(2-hydroxybenzylidineamino) benzene gold (III) complex

In this paper we report non-enzymatic glucose oxidation with N, N′-Bis(2-hydroxybenzylidineamino) benzene gold (III) complex on reduced graphene oxide-gold (rGO-Au) nanoparticle coated modified copper (Cu) electrode. Potassium ferricyanide in 50 mM phosphate buffer solution (pH 7.0) was used as a mediator. The [(Salophen)Au]⁺ on rGO shows good catalytic property for the oxidation of glucose to gluconic acid (GA). The maximum current response produced by Au³⁺/Au⁺ redox potential was monitored by the linear sweep voltammetric method (LSV). As glucose concentration increases the current response at Au⁺³/Au⁺ redox potential decreases simultaneously. On catalytic oxidation of glucose to GA by the complex [(Salophen)Au]⁺, the solution pH reduces to 2.75, which results the decrease of current responses at the Au³⁺/Au⁺ working potential.

Graphical abstract

Direct oxidation of glucose to gluconic acid is achieved adopting non­enzytnatic technique by rGO based heterogeneous catalyst is reported in the present study. N,N'-Bis (2-hydroxy benzylidineatnino) benzene gold (III) complex on rGO-Au nanoparticles is used to fabricate the tnodified electrode. The oxidation mechanism is demonstrated. This work showed the potential of using [(Salophen)Au]⁺ Schiff base complex as a non­enzymatic substitute for glucose oxidize enzyme.