Highly selective amperometric nitrite sensor based on chemically reduced graphene oxide modified electrode

Herein, we report a highly selective amperometric nitrite sensor using a chemically reduced graphene oxide (CR-GO) modified glassy carbon electrode (GCE). The nitrite oxidation peak current (Ip) at CR-GO/GCE was 1.3 and 2.2 fold higher than that of electrochemically reduced graphene oxide (ER-GO) and unmodified GCEs respectively. Moreover, nitrite oxidation at CR-GO/GCE occurred at + 0.8 V, roughly 80 and 130 mV lower potential than ER-GO and unmodified GCEs respectively. CR-GO/GCE detects nitrite in the linear range of 8.9–167 μM, with a sensitivity of 0.0267 A M− 1. The limit of detection (LOD) was 1 μM. This sensor selectively detects nitrite even in the presence of 1000/250 fold of common ions and biological interferrants. CR-GO/GCE also demonstrates an excellent operational stability and good antifouling properties. The excellent recovery (~ 99%) achieved for nitrite determination in various water samples reveal its promising practicality.

► Chemically reduced graphene oxide (CR-GO) modified GCE for highly selective nitrite determination.
► CR-GO has been characterized by FESEM, EDX, ATR-FTIR and Raman spectroscopy.
► CR-GO film has good stability, high selectivity with appreciable repeatability and reproducibility.
► The practical applicability of the proposed sensor has been demonstrated.