A highly selective electrochemical sensor based on molecularly imprinted polypyrrole-modified gold electrode for the determination of glyphosate in cucumber and tap water

Abstract

An electrochemical sensor based on molecularly imprinted polypyrrole (MIPPy) was developed for selective and sensitive detection of the herbicide glyphosate (Gly) in cucumber and tap water samples. The sensor was prepared via synthesis of molecularly imprinted polymers on a gold electrode in the presence of Gly as the template molecule and pyrrole as the functional monomer by cyclic voltammetry (CV). The sensor preparation conditions including the ratio of template to functional monomers, number of CV cycles in the electropolymerization process, the method of template removal, incubation time, and pH were optimized. Under the optimal experimental conditions, the DPV peak currents of hexacyanoferrate/hexacyanoferrite changed linearly with Gly concentration in the range from 5 to 800 ng mL, with a detection limit of 0.27 ng mL (S/N = 3). The sensor was used to detect the concentration of Gly in cucumber and tap water samples, with recoveries ranging from 72.70 to 98.96%. The proposed sensor showed excellent selectivity, good stability and reversibility, and could detect the Gly in real samples rapidly and sensitively. Graphical abstract Schematic illustration of the experimental procedure to detect Gly using the MIPPy electrode.

Recent Development on the Electrochemical Detection of Selected Pesticides: A Focused Review

“…Glyphosate has been reported to be detected using bare and modified electrodes made of gold [28,[37][38][39][40][41][42][43][44], copper [45][46][47], carbon [48][49][50][51][52][53][54], mercury [55][56][57], and platinum [58,59]. Electrochemical methods, type of electrodes, analytical performance, measurement condition, and sample matrix for glyphosate determination are summarized in Table 1.…”

“…Molecularly imprinted polymer (MIP) is an attractive approach in electrochemistry since it allows to specifically recognize target molecules in preference to other closely related compounds based on shape, size, and functional groups [38]. As a result, gold electrodes modified with a molecularly imprinted polymer were developed for glyphosate detection [28].…”

“…Zhang et al [38] also developed a glyphosate moleculary imprinted polypyrrole-modified gold electrode (MIPPy) by electropolymerizing glyphosate and pyrrole using cyclic voltammetry. After polymerization, the embedded glyphosate molecule was extracted from the polypyrrole membrane with an overoxidation method (see Figure 2).…”

Glyphosate Determination by Coupling an Immuno-Magnetic Assay with Electrochemical Sensors

“…To the best of our knowledge, no reports have yet been published on the development of an electrochemical immuno-assay for glyphosate determination. Indeed, in the literature, molecular imprinted polymer-based electrochemical sensors [ 18 , 19 , 20 , 21 , 22 ] have been reported for glyphosate determination but not antibody-based sensors.…”

Determinação de glifosato e ácido aminometilfosfônico em amostras ambientais por cromatografia a líquido em fase reversa controlada por injeção sequencial

“…Songa e colaboradores prepararam um biossensor para a detecção do GLYPH com a deposição eletroquímica de poli-(2,5-dimetóxianilina) (PDMA) dopado com ácido poli-(estirenosulfônico) (PSS) na superfície de um eletrodo de ouro seguida da incorporação da enzima HRP no filme do compósito PDMA-PSS (Songa et al, 2009). Trabalhos utilizando polímeros molecularmente impressos também são encontrados (Prasad et al, 2014;Zhang et al, 2017).…”