para-Nitrophenol detection by an electrochemical approach based on two-dimensional binary metal oxides ZrO₂-Nd₂O₃ nanorod fabricated with PEDOT:PSS onto glassy carbon electrode

In this approach, a wet chemical method was employed to synthesize the nanorods (NRs) of Zirconium oxide − Neodymium Oxide (ZrO₂-Nd₂O₃) in an aqueous solution. Comprehensive characterizations encompassing ultraviolet/visible diffuse reflectance spectroscopy (UV/vis DRS), Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS), alongside field emission scanning electron microscopy (FESEM) equipped with X-ray energy-dispersive spectroscopy (EDS), were applied for optical, elemental, morphological, and structural analyses of resultant material. To fabricate a highly selective and ultra-sensitive electrochemical sensor for para-Nitrophenol (para-NP) in the presence of other interfering toxic chemicals, a glassy carbon electrode (GCE) was modified with a thin layer of ZrO₂-Nd₂O₃NRs. Poly 3,4-ethylenedioxythiophene polystyrene sulfonate (PEDOT:PSS) served as an adhesive conducting binder in this modification process. Subsequently, we introduced a novel electrochemical approach for the first time for the detection of para-NP by making use of newly developed ZrO₂-Nd₂O₃-NRs/PEDOT:PSS/GCE as selective para-NP electrochemical sensor in an aqueous medium. This innovative electrochemical approach exhibited remarkable electrochemical responses, featuring high sensitivity and long-term stability when applied to para-NP detection. The calibration curve demonstrated linearity across broad linear dynamic range (LDR) spanning para-NP concentrations from 0.1 pM to 0.1 mM. Key analytical parameters, including limit of detection (LOD) at signal-to-noise ratio (SNR) of 3, limit of quantification (LOQ), and sensitivity, were determined to be 0.0141 pM, 0.047 pM, and 0.67 μAμM^-1cm⁻², respectively, based also on the gradient of calibration plot. This sensor holds significant promise for real sample analysis aimed at preserving the natural environment. So, this study introduces a novel and well-structured approach to the development of a highly sensitive para-NP sensor utilizing ZrO₂-Nd₂O₃-NRs/PEDOT:PSS/GCE, employing a reliable electrochemical approach.