A highly sensitive method for the determination of 4-NP based on a poly(ionic liquid) hollow nanosphere/gold nanoparticle composite modified glassy carbon electrode was proposed in this paper. The results showed that a good linear relationship between the peak current and the concentration of 4-NP existed in the range of 0.1–120 μM with a detection limit of 3.3 × 10−8 M (S/N = 3) and a correlation coefficient of 0.9964. This method had a lower detection limit and a wider linear range. The effects of some foreign species on the determination were also investigated. The proposed method has been successfully used to determine 4-NP in different water samples.
