Polyimide-multiwalled carbon nanotubes composite as electrochemical sensing platform for the simultaneous detection of nitrophenol isomers

Developing novel electrode materials plays a crucial role in enhancing the electrochemical sensing performance of chemically modified electrodes. This research presents a composite electrode material based on polyimide incorporated with multiwalled carbon nanotubes (PI-MWCNT) for the simultaneous detection of three nitrophenol isomers (NPs). First, the composite was prepared and characterized using microscopies, spectroscopic techniques, and electrochemical experiments. The results indicated that the PI-MWCNT exhibited porosity and roughness, which facilitated the enhancement of its sensing performance. Afterward, the detection capabilities of PI-MWCNT towards NPs were evaluated through voltammetry experiments under optimal conditions. The differential pulse voltammetry (DPV) curves revealed three distinct anodic peaks in the NPs solution, with linear ranges of 1–300 μM for 2-NP, 0.25–250 μM for 3-NP, and 0.25–400 μM for 4-NP. The limits of detection (LOD) were 0.50 μM for both 2-NP and 3-NP, and 0.64 μM for 4-NP. Furthermore, the proposed electrode material was successfully applied to real samples, achieving recovery rates ranging from 92.9% to 106%. This study could contribute to the development of more efficient and sensitive electrochemical sensors.