A sensitive NADH and ethanol biosensor based on graphene–Au nanorods nanocomposites

In this paper, a simple strategy for the synthesis of graphene–Au nanorods hybrid nanosheets (GN–AuNRs) through electrostatic interaction has been demonstrated. Due to the synergistic effect between AuNRs and GN, the hybrid nanosheets exhibited excellent performance toward dihydronicotinamide adenine dinucleotide (NADH) oxidation, with a low detection limit of 6 µM. The linear GN–AuNRs also served as a biocompatible and electroactive matrix for enzyme assembly to facilitate the electron transfer between the enzyme and the electrode. Using alcohol dehydrogenase (ADH) as a model system, a simple and effective sensing platform was developed for ethanol assay. The response displayed a good linear range from 5 to 377 µM with detection limit 1.5 μM. Furthermore, the interference effects of redox active substances, such as uric acid, ascorbic acid and glucose for the proposed biosensor were negligible.