Graphene oxide/NiO nanoparticle composite-ionic liquid modified carbon paste electrode for selective sensing of 4-chlorophenol in the presence of nitrite

- Electrooxidation of 4-chlorophenol was studied by nanostructure sensor.
- This sensor resolved the overlap response of 4-chlorophenol and nitrite.
- This propose sensor was used for the determination of 4-chlorophenol in real samples.

In this study, a high sensitive electrochemical sensor for 4-chlorophenol (4-CP) was established based on graphene oxide NiO/NPs-ionic liquid (IL) (n-hexyl-3-methylimidazolium hexafluoro phosphate) carbon paste electrode. The proposed sensor exhibited strong enrichment effect on 4-CP and gave superior catalytic activity towards the electro-oxidation of 4-CP. On the other hand, the novel sensor was used for determination of 4-CP in the presence of nitrite for the first time. The anodic peaks of 4-CP and nitrite in their mixture can be well separated. At pH 7.0 the two peaks are separated ca. 0.57 and 0.82 V, respectively. Applying square wave voltammetry (SWV), a good linear relationship of the oxidation peak current with respect to concentration of 4-CP cross the range of 1.0-550.0 μM was achieved. The detection limit was evaluated about 0.7 μM. The novel sensor has been successfully applied for the assay of 4-CP in real samples.