Ultrasensitive electrochemical sensor for p-nitrophenyl organophosphates based on ordered mesoporous carbons at low potential without deoxygenization

• Published in: Analytica chimica acta 2014-04, Vol.822, p.23-29
• Main Authors: Zhang, Tingting, Zeng, Lingxing, Han, Lei, Li, Tie, Zheng, Cheng, Wei, Mingdeng, Liu, Aihua
• Format: Article
• Language: English
• Subjects: Buffers; Carbon; Carbon - chemistry; Electrochemical sensor; Electrochemical Techniques; Electrodes; Hydrogen-Ion Concentration; Mathematical analysis; Methyl parathion; Methyl Parathion - analysis; Ordered mesoporous carbons; Organophosphates; p-Nitrophenyl organophosphates; Paraoxon - analysis; Parathion - analysis; Pesticides - analysis; Porosity; Sensors; Voltammetric detection; Voltammetry
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/j.aca.2014.03.023

[Display omitted] •Novel electrochemical sensor for p-nitrophenyl organophosphates based on ordered mesoporous carbons.•Ultrasensitive detection of p-nitrophenyl organophosphates at −0.085V.•Direct detection of p-nitrophenyl OPs without deoxygenization. p-Nitrophenyl organophosphates (OPs) including paraoxon, parathion and methyl parathion, etc, are highly poisonous OPs, for which sensitive and rapid detection method is most needed. In this work, an ultrasensitive electrochemical sensor for the determination of p-nitrophenyl OPs was developed based on ordered mesoporous carbons (OMCs) modified glassy carbon electrode (GCE) (OMCs/GCE). The electrochemical behavior and reaction mechanism of p-nitrophenyl OPs at OMCs/GCE was elaborated by taking paraoxon as an example. Experimental conditions such as buffer pH, preconcentration potential and time were optimized. By using differential pulse voltammetry, the current response of the sensor at −0.085V was linear with concentration within 0.01–1.00μM and 1.00–20μM paraoxon. Similar linear ranges of 0.015–0.5μM and 0.5–10μM were found for parathion, and 0.01–0.5μM and 0.5–10μM for methyl parathion. The low limits of detection were evaluated to be 1.9nM for paraoxon, 3.4nM for parathion and 2.1nM for methyl parathion (S/N=3). Common interfering species had no interference to the detection of p-nitrophenyl OPs. The sensor can be applicable to real samples measurement. Therefore, a simple, sensitive, reproducible and cost-effective electrochemical sensor was proposed for the fast direct determination of trace p-nitrophenyl OPs at low potential without deoxygenization.