The use of graphene nanoribbons as efficient electrochemical sensing material for nitrite determination

• Graphene nanoribbons were synthetized and used as a sensing material.
• Glassy carbon electrode modified with graphene nanoribbons was fabricated.
• Determination of nitrite in tap water samples was studied.
• Wide dynamic range from 0.5 to 105 µM with a detection limit of 0.22 µM was achieved.

In this work new designed, highly sensitive electrochemical method is developed for the determination of nitrites in tap water using glassy carbon electrode modified with graphene nanoribbons (GNs/GCE). Graphene nanoribbons (GNs) have been newly synthetized and aligned to the surface of glassy carbon electrode (GCE) and exhibited excellent electrocatalytic activity for nitrite oxidation with a very high peak currents. Studies about electrochemical behavior and optimization of the most important experimental conditions were done using cyclic voltammetry (CV), while quantitative studies were done with amperometric detection. Nitrite provides a well-defined, oxidation peak at +0.9 V (vs. Ag/AgCl, 3.0 M KCl) in Britton-Robinson buffer solution (BRBS) at pH 3. The influence of most possible interferent ions has been examined and was found to be negligible. Under optimized experimental conditions in BRBS at pH 3 linear calibration curves were obtained in the range from 0.5 to 105 µM with the detection limit of 0.22 µM. Reproducibility of ten replicate measurements of 1 µM of nitrite was estimated to be 1.9%. Proposed method and constructed sensor is successfully applied for the determination of nitrite present in tap water samples without any pretreatment. This developed method represents inexpensive analytical alternative approach compared to other analytical methods.

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