Electrochemical Detection of 2-Nitrophenol Using a Glassy Carbon Electrode Modified with BaO Nanorods

Here, an electrochemical detection approach (differential pulse voltammetry) was employed to develop a 2-nitrophenol (2-NP) sensor probe using a glassy carbon electrode (GCE) coated by wet-chemically synthesized nanorods (NRs) of BaO. The prepared BaO NRs were characterized by field-emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and powder X-ray diffraction (XRD) analysis. The peak currents by differential pulse voltammetric (DPV) analysis of 2-NP are plotted against the concentration to obtain the calibration curve of the 2-NP detection. It was found to be linear from 1.5 to 9.0 mu M, defined as the dynamic range (LDR) for 2-NP detection in phosphate buffer solution. The sensor sensitivity was calculated from the slope of LDR by considering the active surface area of NRs coated on GCE (0.0316 cm(2)) and found as 17.6 mu A mu M-1 cm(-2). The limit of detection (LOD) was calculated as 0.50 +/- 0.025 mu M from the signal/noise (S/N) ratio of 3. Moreover, the sensor analytical parameters such as reproducibility, long-term performing ability (stability), response time and validity in real environmental samples were found acceptable and to give satisfactory results. The development of a nanomaterial-based electrochemical chemical sensor might be an effective approach to sensor technology to detect carcinogenic and hazardous toxins for environmental safety and healthcare fields in a broad scale.

Automated summary

The study developed a 2-nitrophenol sensor probe using barium oxide nanorods coated on a glassy carbon electrode, showing a linear dynamic range and high sensitivity with a detection limit of 0.50 μM. The sensor demonstrated good reproducibility and long-term performance in environmental samples, making it suitable for a wide range of applications in environmental safety and healthcare.