TITLE:
Indirect Electroanalysis of 3-Methyl-4-Nitrophenol in Water Using Carbon Fiber Microelectrode Modified with Nickel Tetrasulfonated Phthalocyanine Complex
AUTHORS:
Yibor Fabrice Roland Bako, Serge Foukmeniok Mbokou, Boukaré Kaboré, Issa Tapsoba, Maxime Pontié
KEYWORDS:
3-Methyl-4-Nitrophenol, Carbon Fiber Microelectrode, Nickel Tetrasulfonated Phthalocyanine, Indirect Electroanalysis, Square Wave Voltammetry
JOURNAL NAME:
Materials Sciences and Applications,
Vol.15 No.2,
January
31,
2024
ABSTRACT: Electrochemical detection of 3-methyl-4-nitrophenol (MNP) in direct phenol oxidation occurs at high potentials and generally leads to progressive passivation of the electrochemical sensor. This study describes the use of a carbon fiber microelectrode modified with a tetrasulfonated nickel phthalocyanine complex for the detection of MNP at a lower potential than that of direct phenol oxidation. The MNP voltammogram showed the presence of an anodic peak at -0.11 V vs SCE, corresponding to the oxidation of the hydroxylamine group generated after the reduction of the nitro group. The effect of buffer pH on the peak current and SWV parameters such as frequency, scan increment, and pulse amplitude were studied and optimized to have better electrochemical response of the proposed sensor. With these optimal parameters, the calibration curve shows that the peak current varied linearly as a function of MNP concentration, leading to a limit of detection (LoD) of 1.1 μg/L. These results show an appreciable sensitivity of the sensor for detecting the MNP at relatively low potentials, making it possible to avoid passivation phenomena.