Potentiometric Sensor for Determination of Cysteine Based on Graphene Oxide-Lead Porphyrin Composite

Combination of the exceptional properties of graphene oxide with the selectivity oflead porphyrin leads to fabricate a novel cysteine-selective sensor. the electrode made of30% pvc, 53% npoe, 2% natpb and 15% go-pp was found to show the most favorablebehavior. the sensor shows a nernstian response (58.8 mv decade-1) in the concentrationwindow of 5.0×10-7-5.0×10-1 m with detection limit of 8.0×10-8 m. the graphene oxide-leadporphyrin composite based sensors displayed a fast and selective response towards cysteinewhich was successfully applied to the determination of cysteine in real sample (humanserum).