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 (I-P) 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 mu M, with a sensitivity of 0.0267 A M-1. The limit of detection (LOD) was 1 mu M. 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 (similar to 99%) achieved for nitrite determination in various water samples reveal its promising practicality. (C) 2012 Elsevier B.V. All rights reserved.