In situ synthesis of palladium nanoparticle–graphene nanohybrids and their application in nonenzymatic glucose biosensors

A nonenzymatic electrochemical biosensor was developed for the detection of glucose based on an electrode modified with palladium nanoparticles (PdNPs)-functioned graphene (nafion–graphene). The palladium nanoparticle–graphene nanohybrids were synthesized using an in situ reduction process. Nafion–graphene was first assembled onto an electrode to chemically adsorb Pd2+. And Pd2+ was subsequently reduced by hydrazine hydrate to form PdNPs in situ. Such a PdNPs–graphene nanohybrids-based electrode shows a very high electrochemical activity for electrocatalytic oxidation of glucose in alkaline medium. The proposed biosensor can be applied to the quantification of glucose with a wide linear range covering from 10 μM to 5 mM (R = 0.998) with a low detection limit of 1 μM. The experiment results also showed that the sensor exhibits good reproducibility and long-term stability, as well as high selectivity with no interference from other potential competing species.