Detection of organophosphorus pesticides: exploring oxime as a probe with improved sensitivity by CeO2-modified electrode. Issue 39 (20th September 2021)

• Record Type: Journal Article
• Authors: Sun, Qiu; Du, Jiyu; Tian, Li; Wu, Jianfeng; Zhang, Xuelin
• Is Part Of: Analytical methods. Volume 13:Issue 39(2021)
• Page Start: 4634
• Page End: 4641
• Publication Date: 2021-09-20
• Subjects: Chemistry, Analytic -- Periodicals; Analytical biochemistry -- Periodicals; Chemical laboratories -- Standards -- Periodicals; 543.1905
• DOI: 10.1039/d1ay01235e
• Languages: English
• ISSNs: 1759-9660

Abstract

Abstract : In this work, an oxime-based electrochemical sensor was prepared to achieve a sensitive and convenient determination of non-electroactive OPs by using the catalytic effect of CeO2 toward oxime oxidation. Abstract : In this paper, the catalytic activity of CeO2 NPs toward oxime oxidation was adopted for the first time to develop an electrochemical sensor with improved sensitivity toward the direct detection of organophosphorus pesticides (OPs) without electrochemical redox activity. To enhance the conductivity of the sensor, CeO2 NPs together with multi-walled carbon nanotubes (MWCNTs) were deposited onto a bare glassy carbon electrode (GCE) by the simple method of drop-casting. The electrochemical properties of the as-prepared sensor were evaluated in K3 [Fe(CN)6 ] solution and the oxidation behavior of pralidoxime (PAM) chloride on the electrodes was characterized by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The results show that the modification of CeO2 onto the electrode not only increases the electroactive area of the electrode but also significantly increases the peak current of PAM chloride oxidation, which confirms that CeO2 has an electrocatalytic effect toward oxime oxidation. To evaluate the sensitivity of the as-fabricated sensor, the inhibition rate of PAM chloride peak current was tested in PAM chloride solution containing different concentrations of chlorpyrifos, which shows a very small detection limit of 2.5 × 10 −9 M. In addition, the sensor successfully achieved a convenient and sensitive determination of OPs in vegetable extracts.