A synergistic polyimide-silver nanowire interface enables simultaneous electrochemical detection of nitrophenol isomers

This research describes a novel electrochemical sensor based on a polyimide-silver nanowire (PI-AgNW) composite that is used to modify a glassy carbon electrode (GCE) for the simultaneous detection of multiple nitrophenol isomers (NPs) with high performance. The synergistic effect of polyimide (PI) doped silver nanowires (AgNWs) improved the selectivity and sensitivity of the fabricated sensor. First, the AgNWs were prepared by the polyol process, and then composited with PI to obtain the target composite. Subsequently, the composite was characterized in detail and was used to modify a GCE for the NP detection. Afterwards, electrochemical measurements were performed for simultaneous detection of three NPs. Under optimal conditions, the results showed that the linear detection ranges were 1-400 μM for 4-nitrophenol (4-NP) and 1-350 μM for both 2-nitrophenol (2-NP) and 3-nitrophenol (3-NP) and the limits of detection (LODs) were 0.081 μM for 2-NP, 0.107 μM for 3-NP, and 0.063 μM for 4-NP, respectively. In addition, the fabricated electrode exhibited excellent reproducibility (RSDs of 2.85% for 2-NP, 2.71% for 3-NP, and 1.80% for 4-NP, respectively) and stability (RSDs of 6.17% for 2-NP, 2.36% for 3-NP, and 3.89% for 4-NP, respectively) over multiple measurements. Moreover, the sensor showed excellent anti-interference capability and was successfully applied to detect NP analytes in real water samples with recoveries ranging from 91.10% to 109.00%. This study emphasizes the potential application of PI-AgNW composites for the rapid detection of NPs in the environment.