Biogenic synthesis of Mn3O4 NPs using Phyllanthus emblica leaf extract for electrochemical sensing of urea

Abstract

Green synthesis integrates green chemistry, environmental remediation, and nanotechnology, focusing on biogenic manganese oxide nanoparticles. This method promotes advanced techniques for human health and safety by minimizing the use of chemical reagents. Herein Phyllanthus emblica leaf extract was used for producing biogenic manganese oxide nanoparticles (B-Mn3O4 NPs), which serve as a reducing, capping, and stabilizing agent in the reaction. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), FTIR, UV–visible, and energy-dispersive X-ray spectroscopy (EDS) analysis were used to investigate the structural, morphological, and spectroscopic studies of Mn3O4 NPs. These analyses confirmed the formation of a single-phase Mn3O4 tetragonal structure. The characterization results indicated that biogenic materials are heterogeneous, making them suitable candidates for electrochemical sensing of urea. This study utilizes urease enzyme to enhance the selectivity, sensitivity, and specificity of B-Mn3O4 NPs-modified electrode towards urea sensing, considering its impact on human health. The selection of the urea analyte arises from the urgent requirement to monitor environmental contamination with urea, which directly affects human health at higher concentrations. To monitor contaminated environments, this study developed ultrasensitive urea biosensors that achieved high sensitivity (2.33 µA µM−1cm−2) and selectivity with a low detection limit (0.0276 µM).