A novel amperometric nitrite sensor based on screen printed carbon electrode modified with graphite/β-cyclodextrin composite

• A highly sensitive amperometric nitrite sensor was developed using GR/CD composite.
• The GR/CD modified SPCE highly enriched the nitrite oxidation with lower overpotential.
• The lower LOD of 0.26 ± 0.01 μM for nitrite is achieved.

A simple and disposable amperometric nitrite sensor was developed based on screen printed carbon electrode (SPCE) modified with graphite (GR) and β-cyclodextrin (CD) composite. The GR/CD composite was prepared by a simple sonication of pristine GR powder in CD aqueous solution. The GR/CD composite modified SPCE showed a higher electrocatalytic activity towards nitrite with lower overpotential (0.81 V) compared with bare, GR and CD modified SPCEs. The edge planes of GR were highly activated in presence of CD and resulting to the high catalytic activity and lower oxidation overpotential for the detection of nitrite. Under optimum conditions, the fabricated GR/CD composite modified SPCE detects the nitrite in the linear concentration range from 0.7 μM to 2.15 mM with a limit of detection of 0.26 ± 0.01 μM. The GR/CD composite modified SPCE also showed a high sensitivity, selectivity, acceptable repeatability and reproducibility along with appropriate operational stability for the detection of nitrite. In addition, the GR/CD composite modified SPCE showed a satisfactory recovery for the detection of nitrite in different water samples, authenticating an excellent practicality of the sensor.