High-sensitivity detection of copper ions using an electrochemical sensor based on in-situ electrodeposited polyaniline nanoparticles

Abstract Polyaniline (PANI) nanoparticles/glassy carbon electrode (GCE) were fabricated by in situ electrodeposition of PANI onto GCE via cyclic voltammetry (CV) and characterized through scanning electron microscopy (SEM), X-ray diffraction (XRD). Compared to bare GCE, the effective active surface area of the electrode modified by PANI nanoparticles increased and its charge transfer resistance reduced, promoting metal ion adsorption and charge transfer, thereby leading to superior detection performance. On the basis of PANI/GCE, an electrochemical sensor was constructed for the electrochemical detection of copper Ions (Cu 2+ ) through differential pulse anodic stripping voltammetry. The results indicated the electrocatalytic reaction of Cu 2+ on the electrode surface of PANI/GCE was governed by diffusion control, and the constructed sensor exhibited a wide detection range from 0.01 mM to 6.55 mM, high sensitivity of 2995.94 µA cm −2 mM −1 , a low limits of detection (LOD) of 0.39 µM, along with excellent repeatability, reproducibility, anti-interference ability and stability. Its practical application was confirmed through recovery tests (99.2%–100.3 %) in spiked lake water, demonstrating strong potential for real-sample analysis.