Rational Design of Molecularly Imprinted Polymers Using Quaternary Ammonium Cations for Glyphosate Detection

Abstract

Molecularly imprinted polymers have emerged as cost-effective and rugged artificial selective sorbents for combination with different sensors. In this study, quaternary ammonium cations, as functional monomers, were systematically evaluated to design imprinted polymers for glyphosate as an important model compound for electrically charged and highly water-soluble chemical compounds. To this aim, a small pool of monomers were used including (3-acrylamidopropyl)trimethylammonium chloride, [2-(acryloyloxy)ethyl]trimethylammonium chloride, and diallyldimethylammonium chloride. The simultaneous interactions between three positively charged monomers and glyphosate were preliminary evaluated using statistical design of the experiment method. Afterwards, different polymers were synthesized at the gold surface of the quartz crystal microbalance sensor using optimized and not optimized glyphosate-monomers ratios. All synthesized polymers were characterized using atomic force microscopy, contact angle, Fourier-transform infrared, and X-ray photoelectron spectroscopy. Evaluated functional monomers showed promise as highly efficient functional monomers, when they are used together and at the optimized ratio, as predicted by the statistical method. Obtained results from the modified sensors were used to develop a simple model describing the binding characteristics at the surface of the different synthesized polymers. This model helps to develop new synthesis strategies for rational design of the highly selective imprinted polymers and to use as a sensing platform for water soluble and polar targets.

Research Progress on Typical Quaternary Ammonium Salt Polymers

“…Because of their characteristics, including their positive charge, good water solubility, easy control of molecular weight, high efficiency, and low toxicity, water-soluble polymers are widely used in traditional and emerging industries. Cationic monomers are mainly divided into three categories: tertiary sulfur salts [8], quaternary phosphonium salts [9] and quaternary ammonium salts [10]. Quaternary ammonium salts, in particular, are low-cost, have a wide range of raw materials which can be used as their source and are safe.…”

A novel electrochemical sensor for glyphosate detection based on Ti3C2Tx/Cu-BTC nanocomposite

“…[8][9][10] Although glyphosate is a non-electroactive compound and cannot be measured at an accessible potential, there have been reports of electrochemical sensing of glyphosate by modifying the electrode and processing the sample. [11][12][13] Prasad et al 14 constructed an electrochemical sensor based on a graphite electrode modied by a dualtemplate imprinted polymer nanomembrane and used it to detect glyphosate in soil. The linear response range and the limit of detection of the sensor to glyphosate are 3.98-176.23 ng ml À1 and 0.35 ng ml À1 , respectively.…”

Molecularly Imprinted Polymer-Based Sensors for Priority Pollutants

“…However, MIPs are commonly used as selective sorbent materials: (I) to develop new selective sample-preparation methods (e.g., solid-phase extraction, solid-phase microextraction, etc.) for various target molecules/ions [17][18][19][20][21][22] and (II) to modify different sensor devices [23][24][25][26].…”

“…However, MIPs are commonly used as selective sorbent materials: (I) to develop new selective sample-preparation methods (e.g., solid-phase extraction, solid-phase microextraction, etc.) for various target molecules/ions [17][18][19][20][21][22] and (II) to modify different sensor devices [23][24][25][26]. As for the EPA Priority Pollutants, MIPs have been also used to develop new selective sample-preparation methods [27][28][29] or to modify different sensor devices (i.e., MIP-modified sensors: it refers to both sensor devices and their modification with MIP materials).…”