Sensitive determination of 4-nitrophenol based on multi-walled carbon nano-tube/ionic liquid/chitosan composite film modified electrode

A composite film modified glassy carbon electrode (GCE) fabricated with spinning coating of multiwalled carbon nano-tube (MWNT) /1-butyl-3-methylimidazolium tetrafluoroborate/chitosan sol was developed for the electrochemical determination of 4-nitrophenol (4-NP). An obvious reduction peak located at about −0.688 V was observed with voltammetric measurements in the potential range from 0.200 V to −1.00 V. Compared with the bare GCE, the reduction peak potential shifted positively and the peak current increased significantly. All experimental parameters for the determination of 4-NP were optimized. It was found that the reduction peak current was proportional to 4-NP concentration in the range from 3.00 × 10−7 to 2.00 × 10−5 mol l−1 with the detect limitation of 1.00 × 10−7 mol l−1 (S/N = 3) after accumulation for 90 s. The proposed method was successfully applied for the determination of trace amounts of 4-NP in lake water.