Highly sensitive electrocatalytic detection of nitrite based on SiC nanoparticles/amine terminated ionic liquid modified glassy carbon electrode integrated with flow injection analysis

• Published in: Sensors and actuators. B, Chemical Chemical, 2014-12, Vol.205, p.136-142
• Main Authors: Salimi, Abdollah, Kurd, Masoumeh, Teymourian, Hazhir, Hallaj, Rahman
• Format: Article
• Language: English
• Subjects: Flow injection analysis; Ionic liquid; Nitrite electrooxidation; Silicon carbide nanoparticles
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2014.08.035

•GCE modified with amine terminated ionic liquid and Si-carbide nanoparticles.•Potential cycling was used for formation of uniformly nanocomposite film onto GCE surface.•The modified electrode showed excellent electrocatalytic activity toward nitrite detection.•Detection limit and sensitivity of the modified electrode were 20nM and 0.0194μAμM−1.•Modified electrode was developed as an amperometric detector coupled with FIA system. Herein, we report a new chemically modified electrode as highly sensitive and selective amperometric nitrite sensor based on a nanocomposite containing an amine-terminated ionic liquid (1-(3-Aminopropyl)-3-methylimidazolium bromide) and silicon carbide nanoparticles (NH2-IL/SiCnp). The scanning electron microscopy (SEM) technique was used to examine the morphology of NH2-IL/SiCnp modified glassy carbon (GC) electrode. It was found that SiCnp/IL layer was uniformly formed on the electrode surface. The modified electrode showed excellent electrocatalytic activity toward nitrite oxidation compared to the bare GC, NH2-IL/GC and SiCnp/GC electrodes. The nitrite oxidation peak current (Ip) at NH2-IL/SiCnp/GC was 3.5 and 1.6-fold higher than that of bare GC and SiC/GC electrodes, respectively, with the peak potential appeared at +0.77V, roughly 180 and 60mV lower potential than bare GC and SiCnp/GC electrodes, respectively. Linear relationship between amperometric current response and nitrite concentration was observed in the range from 50nM to 350μM and the limit of detection was 20nM (S/N=3). In addition, the modified electrode has an excellent anti-interference property in the presence of other potential interfering species as well as a good operational stability and good antifouling properties. The nitrite detection ability of the NH2-IL/SiCnp/GC electrode was further demonstrated using flow injection analysis (FIA). The repeatability of the electrode response in the flow injection analysis (FIA) configuration was evaluated as 2.2% (n=12), and the detection limit of the method was estimated to be 0.3μM (S/N=3). Based on the above results, the proposed system appears to be a highly efficient platform for the development of sensitive and stable nitrite electrochemical sensor.