Revolutionizing electrochemical sensing: Ultra-sensitive non-enzymatic detection of 4-aminophenol with a novel Cu-PANI nanocomposite

This study presents an electrochemical sensor utilizing copper polyaniline (Cu-PANI) nanocomposites (NCs) for the detection of 4-aminophenol. Polyaniline (PANI) is synthesized through the in-situ chemical oxidation polymerization method, which involves the concurrent polymerization of aniline and the generation of copper nanoparticles within the polymer matrix . It is suggested that the copper nanoparticles interact with the mobile groups of polyaniline via electrostatic forces . Fourier transform infrared (FTIR) studies reveal that the synthesized nanocomposites contain functional groups and confirm the interaction between PANI and copper. The surface morphology of the Cu-PANI NCs is examined using scanning electron microscopy (SEM). The electrochemical performance of the Cu-PANI NCs toward 4-AP is assessed through voltammetry (C V ) and differential pulse voltammetry (DPV). It is noted that the glassy carbon electrode (GCE) modified with Cu-PANI (Cu-PANI NCs@GCE) shows an outstanding CV response in the presence of a supporting electrolyte (0.1 M H 2 SO 4 ) at 0.52 V. Differential pulse voltammetry (DPV) identifies 4-AP within the linear range of 1 to 2000 μM at Cu-PANI NCs@GCE. This sensor is distinguished by its low detection limit of 0.002 μM, high sensitivity of 15.462 μA mM 1 cm 2 , exceptional selectivity in complex matrices, and cost-effectiveness, which make it superior to the previously reported sensor, making it ideal for environmental applications. The Cu-PANI NCs-based electrode material is relatively low-cost, robust, selective, sensitive, and possesses an excellent volume-to-surface ratio. The conclusion is that the electrochemical sensor demonstrates proficient sample-analyzing activity and is capable of effectively analyzing sewage, tap water, and industrial wastewater samples. • A cost-effective Cu-PANI nanocomposite sensor enables ultra-trace detection of 4-Aminophenol. • In-situ synthesis ensures high conductivity and stability. • FTIR and SEM confirm strong Cu-PANI interactions and uniform dispersion. • It exhibits high sensitivity (15.462 μA mM −1 cm −2 ), a broad range (1–2000 μM), and an ultralow detection limit (0.002 μM). • The sensor demonstrates robust performance for environmental water analysis.