Development of hydroxyapatite nanoparticles modified pencil graphite electrodes for voltammetric detection of paracetamol and phenol and greenness assessment of the sensor platform

Abstract

Detection of phenolic compounds in water resources has a great importance since their monitoring is obligatory for the evaluation of water quality, and they are major contaminants in water. Phenol and high concentrations of phenolic compounds have serious side effects on both aquatic life and human health. Within the scope of this study, a novel disposable electrochemical sensor platform was fabricated to monitor of phenol (PNL) and an emerging phenolic contaminant, paracetamol (PRL). For this purpose, disposable pencil graphite electrodes (PGEs) were modified with hydroxyapatite nanoparticles (HaNP) following a novel method. First, the PGEs were chemically activated using NaOH (N-PGEs), and modified with HaNPs (HaNP/N-PGEs) in an acidic media to activate positive charges of HaNP. Then, the HaNP-N/PGEs were used for the voltammetric detection of PRL and PNL. The effect of the experimental parameters such as pH, scan rate and concentration of PRL or PNL were investigated using cyclic voltammetry (CV) technique. Lower LOD values could be obtained by using HaNP/NPGEs in comparison to the N-PGEs due to the fact that enhanced electrochemically active surface area was obtained by the modification of HaNP on the PGE surface. Simultaneous detection of PRL and PNL was tested using differential pulse voltammetry (DPV) technique. The selectivity of the sensor was also evaluated in the presence of inorganic and organic compounds, and PRL and PNL detection was performed in drinking water and wastewater samples. The greennness level of the sensor was evaluated using Analytical GREEnness Metric Approach and Software (AGREE). This is the first study in the literature in terms of (i) the development of HaNP/ N-PGEs, (ii) voltammetric PRL/PNL detection using HaNP/N-PGEs, and (iii) greenness assessment of a PGE-based electrochemical sensor. The HaNP/N-PGEs based electrochemical sensor platform represents a novel and green prototype towards future hand-held devices for reliable monitoring of phenolic compounds.