Configuration of molecular imprinted polymer for electrochemical atrazine detection

Facile and innovative application of surfactant-modified-zeolite from Austrian fly ash for glyphosate removal from water solution

This study highlights a pioneering approach in the development of an efficient, affordable, and economically feasible adsorbent specifically tailored for the removal of glyphosate (Gly) from contaminated water. To accomplish this objective, a low-cost and pure NaA Zeolite (NaAZ) was synthesized with 93% crystallinity from Austrian fly ash (AFA) as a precursor for the first-time. Taguchi design was employed to optimize critical parameters such as the SiO2/Al2O3 ratio, alkalinity concentration, time, and temperature. The cation exchange capacity (CEC) and external cation exchange capacity (ECEC) are determined as critical factors for the modification process. Subsequently, the pure NaAZ was modified with hexadecyl trimethyl ammonium chloride (HDTMAC), a cationic surfactant. The utilization of surfactant-modified zeolite (SMZ) for Gly removal demonstrates its innovative application in this field, highlighting its enhanced adsorption capacity and optimized surface properties. The AFA, NaAZ, and SMZ were characterized using analytical techniques including XRD, XRF, FTIR-ATR, SEM, TGA, BET, CHNSO analyzer and ICP-OES. The adsorbent exhibited effective Gly removal through its pH-dependent charge properties (pH 2-10), with an optimized pH 6 facilitating a significant electrostatic interaction between the adsorbent and Gly. SMZ demonstrated remarkable adsorption capacity and removal efficacy, surpassing most reported adsorbents with values of 769.23 mg/g and 98.92% respectively. Our study demonstrates the significant advantage of the SMZ, with a low leaching concentration of only 6 ppm after 60 days, ensuring environmental safety, long-term stability, and public health considerations. The kinetics of the adsorption process was well described by the pseudo-second order and the Freundlich isotherm. Pore diffusion and H-bonding were postulated to be involved in physisorption, whereas electrophilic interactions led to chemisorption type of adsorption. Consequently, SMZ provides a practical significance, broad applicability and promising solution for Gly removal, facilitating sustainable water treatment.

Isotherm and Electrochemical Properties of Atrazine Sensing Using PVC/MIP: Effect of Porogenic Solvent Concentration Ratio

Widespread atrazine use is associated with an increasing incidence of contamination of drinking water. Thus, a biosensor using molecularly imprinted polymers (MIPs) was developed to detect the amount of atrazine in water to ensure prevention of exposure levels that could lead to reproductive effects in living organisms. In this study, the influence of the porogen on the selectivity of MIPs was investigated. The porogen plays a pivotal role in molecular imprinting as it affects the physical properties and governs the prepolymerization complex of the resulting polymer, which in turn firmly defines the recognition properties of the resulting molecularly imprinted polymer (MIP). Therefore, bulk MIPs against atrazine (Atr) were synthesized based on methacrylic acid (MAA) as a functional monomer and ethyleneglycol dimethacrylate (EGDMA) as a crosslinker; they were prepared in toluene and dimethyl sulfoxide (DMSO). The imprinting factor, binding capacity, and structural stability were evaluated using the respective porogenic solvents. Along with the characterization of the morphology of the obtained polymers via SEM and BET analysis, the kinetic and adsorption analyses were demonstrated and verified. The highest imprinting factor, binding capacity, and the highest structural stability were found to be on polymer synthesized in a medium of MAA and EGDMA, which contained 90% toluene and 10% DMSO as porogen. Moreover, the response for Atr concentrations by the PVC-based electrochemical sensor was found to be at a detection limit of 0.0049 μM (S/N = 3). The sensor proved to be an effective sensor with high sensitivity and low Limit of Detection (LOD) for Atr detection. The construction of the sensor will act as a baseline for a fully functionalized membrane sensor.

A Review of Nanocomposite-Modified Electrochemical Sensors for Water Quality Monitoring

Electrochemical sensors play a significant role in detecting chemical ions, molecules, and pathogens in water and other applications. These sensors are sensitive, portable, fast, inexpensive, and suitable for online and in-situ measurements compared to other methods. They can provide the detection for any compound that can undergo certain transformations within a potential window. It enables applications in multiple ion detection, mainly since these sensors are primarily non-specific. In this paper, we provide a survey of electrochemical sensors for the detection of water contaminants, i.e., pesticides, nitrate, nitrite, phosphorus, water hardeners, disinfectant, and other emergent contaminants (phenol, estrogen, gallic acid etc.). We focus on the influence of surface modification of the working electrodes by carbon nanomaterials, metallic nanostructures, imprinted polymers and evaluate the corresponding sensing performance. Especially for pesticides, which are challenging and need special care, we highlight biosensors, such as enzymatic sensors, immunobiosensor, aptasensors, and biomimetic sensors. We discuss the sensors' overall performance, especially concerning real-sample performance and the capability for actual field application.

Effect of the Molecularly Imprinted Polymer Component Ratio on Analytical Performance

Molecular imprinting technology is a new analytical method that is highly selective and specific for certain analytes in artificial receptor design. The renewal possibilities of this technology make it an ideal material for sundry application fields. Molecularly imprinted polymers (MIPs) are polymeric matrices that have molecules printed on their surfaces; these surfaces can chemically interact with molecules or follow the pattern of the available template cavities obtained using imprinting technology. A MIP is useful for separating and analysing complex samples, such as biological fluids and environmental samples, because it is a strong analytical recognition element that can mimick natural recognition entities like biological receptors and antibodies. The MIP components consist of the target template, functional monomer, crosslinker, polymerisation initiator, and porogen. The effectiveness and selectivity of a MIP are greatly influenced by variations in the components. This review will provide an overview of the effect of MIP component ratio on analytical performance to each target analyte; it will also provide a strategy to obtain the best MIP performance. For every MIP, each template : monomer : crosslinker ratio shows a distinct performance for a specific analyte. The effects of the template : monomer : crosslinker ratio on a MIP's analytical performances-measured by the imprinting factor, sorbent binding capacity, and sorbent selectivity-are briefly outlined.