Sensitive electrochemical sensor for nitrite ions based on rose-like AuNPs/MoS2/graphene composite

Nitrite ions (NO 2 − ) have been widely used in the food and drink industry as preservatives. However, the NO 2 − discharged into the environment is harmful to the ecosystem and human health. Due to its potential toxicity, selective and sensitive detection of nitrite is important. In this work, a rose-like Au nanoparticles/MoS 2 nanoflower/graphene (AuNPs/MoS 2 /GN) composite was fabricated using a one-pot hydrothermal method without the addition of any extra reductant for use in nitrite detection. Graphene acts as an efficient matrix for the growth of MoS 2 nanoflower (NF), and the edges of the MoS 2 NF subsequently load AuNPs. The obtained AuNPs/MoS 2 /GN composite exhibits excellent electrooxidative activity toward nitrite ions, which is attributable to its large specific surface area, good conductivity, and the synergistic catalysis of each component. Accordingly, we propose a rapid, sensitive, and cost-effective electrochemical method for nitrite detection, which achieved a linear dynamic range of 5.0 μM to 5.0 mM with a detection limit of 1.0 μM. The present work provides not only a general one-pot synthesis method for a variety of noble–transition metal dichalcogenides nanohybrids , but also an example of the fabrication of an electrochemical nitrite sensor using a nanohybrid as an enhanced material, an approach that can easily be extended to other sensors.