Amino-functionalized graphene oxide/polyaniline nanocomposite: a versatile platform for ultrasensitive Pb²⁺ ion sensing

Pb²⁺ emerges as a potent toxic element, a consequence of anthropogenic activities, imparting multifaceted adverse effects on human health and the ecosystem. This work focuses on the utilization of cutting-edge composite materials, specifically amino-functionalized graphene oxide/polyaniline (AMGO_PANI), for the voltammetric determination of Pb²⁺ ions. The amino functionalization of graphene oxide was meticulously achieved through the hydrothermal technique, leading to the formation of composites with polyaniline (PANI) by varying amino-functionalized graphene oxide (AMGO) concentrations. Physicochemical analyses of the synthesized materials were carried out using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), and Raman spectroscopy, while electrochemical behavior was comprehensively assessed through cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) methodologies. The use of the AMGO_PANI nanocomposite demonstrated remarkable efficacy in the electrochemical detection of Pb²⁺, boasting a discernible limit of detection (LOD) as low as 1 nM. Additionally, the sensor exhibited commendable attributes, including selectivity, sensitivity, repeatability, and reproducibility. Notably, minimal relative standard deviation (RSD) values were observed when analyzing real-world tap water samples. Consequently, AMGO_PANI emerges as a promising Pb²⁺ sensor, with potential applications in environmental monitoring and the protection of human health.