Abstract
A sensitive amperometric sensor has been developed for the detection of dopamine (DA) at graphene nanosheets (GNS) decorated bismuth nanoparticles (Bi) composite film modified electrode. GNS-Bi nanocomposite has been prepared by simple solution based method and its successful formation was confirmed by scanning electron microcopy and Energy-dispersive X-ray spectroscopy studies. GNS-Bi nanocomposite film modified glassy carbon electrode (GCE) was fabricated and employed for the electrocatalysis of dopamine (DA). At GNS-Bi/GCE, well-defined redox couple corresponding to the redox reaction of DA was observed at the formal potential of + 0.195 V with highly enhanced peak currents. An amperometric sensor has been fabricated based on the GNS-Bi/GCE, which exhibited excellent electrocatalytic ability to the determination of DA. The amperometric sensor presents outstanding electrocatalytic parameters such as wide linear range (1 μM to 30 μM ), high sensitivity (5.304 μAμM-1 cm-2) and low detection limit (0.35 μM). Real sample analysis of the sensor has been addressed in pharmaceutical sample which presents appreciable recovery results. The main advantages of sensor are very simple electrode fabrication procedures, roughed and stable, fast in sensing and highly reproducible sensor for DA. In addition, the sensor is exhibited high stability and acceptable repeatability and reproducibility results.