Sensitive voltammetric determination of vanillin with an AuPd nanoparticles−graphene composite modified electrode

• A novel AuPd alloy nanoparticles−graphene hybrid modified electrode was prepared.
• It presented high electrocatalysis to the oxidation of vanillin.
• Vanillin can produce a sensitive oxidation peak at the hybrid film.
• The electrode showed good performance when used to sense vanillin.

In this work, graphene oxide was reduced to graphene with an endogenous reducing agent from dimethylformamide, and then AuPd alloy nanoparticles were electrodeposited on the graphene film. The obtained AuPd–graphene hybrid film was characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction and voltammetry. The electrochemical behavior of vanillin was studied using the AuPd–graphene hybrid based electrode. It presented high electrocatalytic activity and vanillin could produce a sensitive oxidation peak at it. Under the optimal conditions, the peak current was linear to the concentration of vanillin in the ranges of 0.1–7 and 10–40 μM. The sensitivities were 1.60 and 0.170 mA mM−1 cm−2, respectively; the detection limit was 20 nM. The electrode was successfully applied to the detection of vanillin in vanilla bean, vanilla tea and biscuit samples.