Fabrication of Zr(IV) Modified Gold Electrode via Layer-by-Layer Self-Assembly for Methyl Parathion

Abstract

A facile way was developed to fabricate Zr(IV) cation modified gold electrode for high-performance electrochemical sensing of methyl parathion (MP) via layer-by-layer self-assembly. The electrode was prepared by sequentially absorbing 11-mercaptoundecyl-phosphoric acid (MDPA) and Zr(IV) cation on gold electrode through strong chelating interactions between gold and -SH as well as Zr(IV) cation and phosphoric groups of MDPA. Fourier transform infrared spectrophotometry, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy and cyclic voltammetry were employed for the characterization of morphologies and electrochemical properties. The sensor was used to determine MP by square wave voltammetry. The cathodic peak current (at + 0.25 V vs saturated calomel electrode) increases linearly in the range of 1.0 − 180.0 ng ml −1 under optimized conditions. And the detection limit is low to 0.22 ng ml −1 (based on a signal-to-noise ratio of 3). The electrode is successfully used to detect MP in the real water sample with recoveries of 98.97%-102.4% and RSDs of 0.21%-1.99% (n = 3) at three spiked levels.The proposed method provides one simple way to prepare Zr(IV) cation modified electrode for the fast determination of MP. The reliability and accuracy of the method is validated by independent assays with HPLC.

Stripping Voltammetric Determination of Methyl Parathion at Activated Carbon Nanopowder Modified Electrode

“…The limit of detection was found to be as low as 2.5 nmol L −1 (S/N=3). The revision of the recently published papers revealed, that the detection limit for methyl parathion determination reached applying electrochemical sensors varies over a large range: from 0.05 nmol L −1 to 53 nmol L −1 (Table 1) [8–20]. The European Council Directive 98/83/EC on the quality of water intended for human consumption (Council Directive 98/83/EC, 1998) sets the limit value of the individual pesticides in drinking water at 0.1 μg L −1 (3.8 nmol L −1 ), and that of the total pesticides at 0.5 μg L −1 (19 nmol L −1 ), while the U.S. Environmental Protection Agency Office of Ground Water and Drinking Water (OGWDW) sets the health advisory level for methyl parathion in drinking water at 2 μg L −1 (7.6 nmol L −1 ).…”

“…Therefore, they emerged as a promising alternative to the time‐consuming and expensive off‐site chromatographic techniques currently used [5–7]. Some typical examples include the electrochemical quantification of nitrophenyl substituted OPs, selecting methyl parathion as a model [8–25],…”

Simultaneous Hydrolysis and Detection of Organophosphate by Benzimidazole Containing Ligand-Based Zinc(II) Complexes

“…Electrochemical techniques through modifying electrodes with active catalysts have been employed for the determination of organophosphate [25][26][27][28]. For example, electrodes modified with different nanocomposite such as CuO-TiO 2 [29], Ag/graphene [30], Au/MWCNT [31], ZrO 2 /Au [32], ZnO/GO [33], Zr(IV)/Au [34] and MnO 2 [35] have been used for the detection of organophosphate compounds. However, to the best of our knowledge, there is no data reported for metal complexes modified carbon-based electrodes for both hydrolysis and sensing applications.…”