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

Combination of the exceptional properties of graphene oxide with the selectivity of lead porphyrin leads to fabricate a novel cysteine-selective sensor. The electrode made of 30% PVC, 53% NPOE, 2% NaTPB and 15% GO-PP was found to show the most favorable behavior. The sensor shows a Nernstian response (58.8 mV decade-1) in the concentration window of 5.0×10-7-5.0×10-1 M with detection limit of 8.0×10-8 M. The graphene oxide-lead porphyrin composite based sensors displayed a fast and selective response towards cysteine which was successfully applied to the determination of cysteine in real sample (human serum).