Electrochemical Sensors Based on Modification of Carbon Fiber Microelectrode by Nickel Phthalocyanine Polymer for 3-Methyl-4-Nitrophenol Analysis in Water

Abstract

Abstract3-methyl-4-nitrophenol (MNP) is the main by-product of the organophosphate insecticide fenitrothion (FT), used in locust control. MNP is highly toxic because it is an endocrine disruptor and then may cause adverse in the biological systems. Then, it is necessary to develop analytical methods for determination of this pollutant in the environment. In this sense, we reported herein the development of an electrochemical sensor for the detection of 3-methyl-4-nitrophenol (MNP), one of the metabolites of fenitrothion (FT), by using naked and modified carbon fiber microelectrode (CFME) by nickel tetrasulfonated phthalocyanine polymer (CFME/p-NiTSPc). The voltammogram showed that MNP presents one irreversible anodic peak corresponding to the oxidation of the phenol group at 0.9 V vs Ag/AgCl. The effect of pH of the buffer on the peak current and SWV parameters such as frequency, scan increment and pulse amplitude were investigated in order to optimize the electrochemical response of the sensor. The obtained results lead to the following optimum value: pH = 6; frequency = 25 Hz, pulse amplitude = 50 mV, scan increment = 10 mV. With these optimum values, the calibration curves show that the peak current varied linearly upon MNP concentration leading to a limit of detection (LoD) for naked CFME close to 3 µg/L whereas for CFME modified by p-NiTSPc, it reaches 0.75 µg/L. This results prove that the presence of p-NiTSPc increasing the sensitivity of the sensor could be used to monitor 3-methyl-4-nitro-phenol residue in real matrix.

Indirect Electroanalysis of 3-Methyl-4-Nitrophenol in Water Using Carbon Fiber Microelectrode Modified with Nickel Tetrasulfonated Phthalocyanine Complex

“…Figure 7 shows that the peak current varies linearly with the concentration of MNP in the range of 10 -100 μg/L with a regression equation of I_p (nA) = 2.68C (μg/L) + 358 and a limit of detection (3 S/m) of 1.1 μg/L. Although this value is very similar to the detection limit obtained in our previous work (previous LoD = 0.75 μg/L) [1] when detecting MNP in direct oxidation of the phenol group, analysis in indirect oxidation could be attractive to exploit because it is without risk of passivation. Thus, considering the proximity of the detection limit values, indirect MNP oxidation analysis could be an alternative to direct MNP oxidation detection without altering its sensitivity through any electrode passivation.…”

“…Organophosphorus (OPs) compounds are commonly used pesticides to control insects and improve crop yields. In Burkina Faso, fenitrothion (FT), an organophosphate insecticide, is widely used in cotton cultivation and during locust invasions [1] [2]. Like other organophosphates, FT acts by inhibiting acetylcholinesterase, which disrupts nerve impulse transmission [3] [4].…”

“…However, to our knowledge, very few studies report the electrochemical detection of MNP, the most stable metabolite of fenitrothion. Thus, in a previous work [1], we described an electrochemical sensor based on an ultramicroelectrode modified with a nickel tetrasulfonated phthalocyanine complex to determine MNP in the direct oxidation of the phenol group. In another work [2], we reported electrode passivation during direct electrooxidation of MNP, and we proposed an anti-passivation strategy to mitigate this issue.…”

Sensitive Determination of Nicotine on PolyNiTSPc Electrodeposited Glassy Carbon Electrode: Investigation of Reaction Mechanism

“…Several studies were reported the use of Poly-NiTSPc film modified electrodes for different applications such as methanol electro-oxidation on a Pt/C catalyst [20], free sulfite electrooxidation [21], detection of 3-methylpara-nitrophenol (MNP) [22], Methyl-parathion (MPT) [23], 4-Nitrophenol (PNP) [24] and nitrite [25], determination of dopamine (DA) in the presence of ascorbic acid (AA) and uric acid (UA) [26], NO microsensor [27] and Microbial Fuel Cells [28]. Several studies were reported the use of Poly-NiTSPc film modified electrodes for different applications such as methanol electro-oxidation on a Pt/C catalyst [20], free sulfite electrooxidation [21], detection of 3-methylpara-nitrophenol (MNP) [22], Methyl-parathion (MPT) [23], 4-Nitrophenol (PNP) [24] and nitrite [25], determination of dopamine (DA) in the presence of ascorbic acid (AA) and uric acid (UA) [26], NO microsensor [27] and Microbial Fuel Cells [28].…”

Sensitive determination of diuron on zinc oxide nanoparticles modified carbon paste electrode in soil and water samples

“…The curve of the variation of the potential as a function of the pH is shown in (Figure 5C) from which the potential was shown to decrease linearly as the pH increases. The slope of the linear regression was estimated at 73 mV/pH indicating that there is a transfer of one electron per proton [46, [51][52][53]. Furthermore, the representation of the peak current as a function of the pH (Figure 5D) indicates a maximum current reached at pH = 8.…”