Abstract
Herein, a facile wet chemical method was used to synthesize doped semiconductor Ag2O@La2O3 nanosheets (NSs) in an alkaline medium. Characterization tools such as ultraviolet/visible spectroscopy (UV/vis), Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) in addition to field emission scanning electron microscopy (FESEM) equipped with X-ray energy-dispersive spectroscopy (EDS) were used for the optical, elemental, morphological, and structural characterizations of Ag2O@La2O3 NSs. A glassy carbon electrode (GCE) was modified by the fabrication of a thin layer of Ag2O@La2O3 NSs with 5% ethanolic Nafion as a conducting binder onto its flat surface for the development of a selective as well as ultra-sensitive 3-methoxyaniline (3-MA) electrochemical sensor. A simple electrochemical technique was used for the first time to detect 3-MA via an electrochemical approach using newly designed Ag2O@La2O3 NSs/Nafion/GCE as a selective 3-MA electrochemical sensor in an aqueous system. Thus, electrochemical responses along with higher sensitivity, a large dynamic range and long-term stability towards 3-MA were observed by this electrochemical approach. The calibration curve was found to be linear over a wide linear dynamic range (LDR) of 3-MA concentrations (0.1 nM to 0.1 mM). The limit of detection (LOD) at a signal-to-noise ratio of 3 (S/N = 3), limit of quantification (LOQ) and sensitivity were found to be 0.085 +/- 0.002 nM, 0.28 +/- 0.02 nM and 0.0110 mA mM(-1) cm(-2), respectively, from the gradient of the calibration plot. Hence, this is a new and well-organized way for the development of a 3-MA electrochemical sensor based on Ag2O@La2O3 NS-modified GCE, and it can be applied in real sample analysis for the safety of the natural environment. To the best of our knowledge, this report is the first study on the development of a highly sensitive 3-MA sensor based on Ag2O@La2O3 NSs/Nafion/GCE using a reliable electrochemical technique.