Review-Recent Developments on Graphene-Based Electrochemical Sensors toward Nitrite

Nitrite (NO2-) has been extensively applied in agricultural and industrial products and is often found in various foodstuff, tap water, biological samples and environmental systems. However, NO2- as a toxic contaminant probably threaten the human health by producing highly carcinogenic N-nitrosamines. Compared with the traditional analytical techniques, electroanalytical method has considerable advantages such as cost-effective, rapidness, facile operation, and easy miniaturization. Graphene nanocomposites have significant synergistic electrocatalytic effect toward the nitrite redox, which could eventually amplify the electrochemical response signals, and improve the selectivity, sensitivity, and practicability for the nitrite detection in various real samples. The recent developments on graphene-based nitrite electrochemical sensors are reviewed from the view of sensing materials, including graphene, metal nanoparticle/graphene composites, nanostructured metal compound/graphene composites, polymer/graphene composites, MOF/graphene composites, enzyme/graphene composites, MWCNT/graphene composites, and electron mediator/graphene composites. Moreover, the sensing performances including detection ranges, limit of detection (LOD) and sensitivity are tabulated. Finally, the major drawbacks, opportunities and challenges of graphene-based nitrite electrochemical sensors are also discussed. (C) 2019 The Electrochemical Society.