Detection Of Atrazine Research Articles

Antibody conjugated glycine doped polyaniline nanofilms as efficient biosensor for atrazine

Atrazine is an important member of triazine family of pesticides. The development of its detection methods gained great attention due to the potential health risks associated with its contamination in various media including water, soil, and food. The contamination of atrazine in drinking water beyond the legal permissible limit of EPA (e.g. 3 ng ml−1) may cause various damages to living organisms (e.g. heart, urinary, and limb defects). In this research, we discuss the potential significance of a highly sensitive conductometric immunosensor for sensing the atrazine pesticide. To this end, electrochemical assembly of glycine doped polyaniline (PAni) nanofilms on silicon (Si) substrate was built and modified further with anti-atrazine antibodies. The herein developed immunosensor offered highly sensitive detection of atrazine with a low detection limit of 0.07 ng ml−1. The proposed biosensor was simple in design with excellent performance in terms of its sensitivity, stability and specificity.Highlights•Glycine doped PAni nanofilms have been electropolymerized on Silicon substrates.•Functionality of the above thin films provides opportunity to develop an immunosensing platform.•Highly sensitive and specific detection of atrazine has been realized over a wide concentration range with a LOD of 0.07 ng ml−1.Novelty statementAtrazine is a widely used pesticide in the agriculture sector. It is highly recommended to develop simple biosensing systems for enabling the prospect of routine monitoring. The present research for the first time proposes the design of a glycine doped PAni based simple and highly effective biosensor for the atrazine pesticide. The doping of glycine has easily generated functional groups on the nano-PAni material for further convenient immobilization of anti-atrazine antibodies. The proposed sensor can be highlighted with advantages like ease of fabrication, use of environment friendly functionalization agent, specificity, wide linearity, and good sensitivity with enhanced viability.

Electrochemical detection of atrazine in wastewater samples by copper oxide (CuO) nanoparticles ionic liquid modified electrode

In the present report, a new voltammetric sensor based on copper oxide nanoparticles involved in 2-(3-acetoxy-4-methoxybenzylidenamino)-thiophenol (AMT) ionic liquid (CuO NPs/ILs) was developed for atrazine (ATR) analysis. Firstly, the CuO NPs/ILs modified surface was investigated by using transmission electron microscopy (TEM), X-ray diffraction (XRD), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and energy dispersive X-ray analysis (EDX). The linearity range and the detection limit (LOD) of the prepared sensor were calculated as 1.0×10−11–2.0×10−9 and 2.0×10−12M, respectively. Voltammetric sensor was also applied to wastewater samples with high recovery.

A highly sensitive impedimetric aptasensor for the selective detection of acetamiprid and atrazine based on microwires formed by platinum nanoparticles

A novel impedimetric biosensor was developed for the detection of the two extensively used pesticides, acetamiprid and atrazine. By employing the sputtering and e-beam lithography techniques, platinum nanoparticles (Pt NPs) were deposited in a bridge-like arrangement, in between interdigitated electrodes (IDEs). The resulting Pt NP microwires were chemically functionalized to allow the covalent immobilization of aptamers against the two target analytes onto the sensor surfaces. The biosensing platform facilitated charge transfer through the microwire-bridged IDEs, while upon analyte binding to the immobilized aptamers electron transfer was hindered, resulting in an increase of the electrochemical cell's impedance. The combination of Pt NPs microwires and aptamers allowed the sensitive and highly selective detection of acetamiprid with a linear range of response in the range of 10pM to 100nM with a limit of detection (LoD) at 1pM, and of atrazine with a linear range of responses from 100pM to 1μM and a LoD at 10pM respectively. Its performance was tested against a number of other commonly used pesticides as well as in real water samples.

Toxicity, degradation and analysis of the herbicide atrazine

Excessive use of pesticides and herbicides is a major environmental and health concern worldwide. Atrazine, a synthetic triazine herbicide commonly used to control grassy and broadleaf weeds in crops, is a major pollutant of soil and water ecosystems. Atrazine modifies the growth, enzymatic processes and photosynthesis in plants. Atrazine exerts mutagenicity, genotoxicity, defective cell division, erroneous lipid synthesis and hormonal imbalance in aquatic fauna and nontarget animals. It has threatened the sustainability of agricultural soils due to detrimental effects on resident soil microbial communities. The detection of atrazine in soil and reservoir sites is usually made by IR spectroscopy, ELISA, HPLC, UPLC, LC–MS and GC–MS techniques. HPLC/LC–MS and GC–MS techniques are considered the most effective tools, having detection limits up to ppb levels in different matrices. Biodegradation of atrazine by microbial species is increasingly being recognized as an eco-friendly, economically feasible and sustainable bioremediation strategy. This review presents the toxicity, analytical techniques, abiotic degradation and microbial metabolism of atrazine.

Electrochemical Detection of Atrazine by Platinum Nanoparticles/Carbon Nitride Nanotubes with Molecularly Imprinted Polymer

In this Article, a new electrochemical sensor based on molecular imprinting polymer (MIP) and platinum nanoparticles (Pt NPs)/carbon nitride nanotubes (C3N4 NTs) nanocomposite was developed for atrazine (ATR) analysis. First, the structures of prepared nanocomposites and surfaces were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDX). After the characterization studies, ATR-imprinted glassy carbon electrode (GCE) based on Pt NPs/C3N4 NTs nanocomposite was developed by 100 mM phenol containing 25 nM ATR. The linearity range and the detection limit of the molecular imprinted sensor were calculated as 1.0 × 10–12–1.0 × 10–10 and 1.5 × 10–13 M, respectively. In addition, the voltammetric sensor was applied to wastewater samples with high recovery.

A new electrochemical platform for ultrasensitive detection of atrazine based on modified self-ordered Nb2O5 nanotube arrays

In this work, one dimensional self-ordered Nb2O5 nanotube arrays were grown from Nb substrate by anodization method and were modified with optimum amounts of chitosan (CS) and carboxyl-Fe3O4 nanoparticles. These nanocomposites were characterized by SEM, XRD, and XPS and used as electrode materials for the direct detection of atrazine traces in aqueous solution. The test signals were obtained from the interaction between anti-atrazine monoclonal antibody and atrazine and recorded using via differential pulse voltammetric (DPV) method in electrochemical system. These modified one-dimensional Nb2O5 nanotube arrays showed the linear detection ranges of 0.04ng/mL–0.6ng/mL and a detection limit of 0.018ng/mL for atrazine under the optimized conditions. These above results indicate that these Nb2O5 nanotube arrays are promising candidates for electrochemical sensors.

Seasonal detection of atrazine and atzA in man-made waterways receiving agricultural runoff in a subtropical, semi-arid environment (Hidalgo County, Texas, USA).

Atrazine is a widely-used herbicide that can impact non-target organisms in the environment but can be biologically degraded by several types of microorganisms. In this study, the gene atzA, which encodes for the initial step in bacterially-mediated atrazine degradation, was used as an indicator of atrazine pollution in agricultural canals located in Hidalgo County, Texas, USA. The concentration of atrazine and atzA were monitored once per month for 12 months during 2010-2011. Atrazine was measured using an enzyme-linked immunosorbent assay; atzA abundance was monitored using Quantitative Polymerase Chain Reaction (Q-PCR) analyses. Abundance of atrazine and atzA were compared with rainy versus dry months and during planting versus non-planting months. Results showed that atrazine levels varied from below detection to 0.43ppb and were not influenced by precipitation or planting season. Concentrations of the gene atzA were significantly different in rainy versus dry months; during planting versus non-planting times of the year; and in the interaction of precipitation and planting season. The highest concentration of atzA, approx. 4.57 × 108 gene copies ml-1, was detected in July 2010-a rainy, planting month in Hidalgo County, South Texas. However, atrazine was below detection during that month. We conclude that Q-PCR using atzA as an indicator gene is a potential method for monitoring low levels of atrazine pollution in environmental samples.

Inkjet-printed microtiter plates for portable electrochemical immunoassays

Herein, we present the large-scale fabrication of multiplexed three-electrode sensors used in a point-of-care device platform that couples a magnetic bead-based immunoassay strategy with amperometric detection for rapid and highly sensitive analysis. The multiplexed sensors consisted of eight independent electrochemical cells, each with a carbon nanotube (CNT) working electrode, CNT counter electrode and a silver-silver chloride quasi-reference electrode. The microchips were fabricated on flexible polyethylene terephthalate (PET) sheets by sequential multilayer inkjet printing (IJP) of silver, CNT and insulator inks that were either simultaneously or subsequently post-processed (e.g. through UV photo-polymerization or photonic curing). Finally, plastic wells were mounted on top of the inkjet-printed patterns to obtain an eight-well microtiter plate where each well had a solution capacity of 50μL. Due to the high precision of the IJP process, the microtiter plates showed high reproducibility among the individual electrochemical cells (1–2% of deviation). Furthermore, the microchips can be reusable for at least up to 20 times as demonstrated herein. In a customized multichannel potentiostat with eight implemented magnets matching the positions of the working electrodes, the electrochemical readout of magnetic bead based sandwich and competitive immunoassays was successfully realized for the detection of thyroid-stimulating hormone (TSH) and atrazine (ATR) in aqueous and urine samples, respectively. The achieved limits of detection for ATR (i.e. 0.01μg/L) and TSH (i.e. 0.5μIU/mL) demonstrated the potential of the IJP microtiter plates for the environmental and biological quantification of analytes in a very reliable high throughput platform. This work shows that IJP has certainly reached the status of a batch production tool for electroanalytical sensing platforms.

Plastic antibody based surface plasmon resonance nanosensors for selective atrazine detection

This study reports a surface plasmon resonance (SPR) based affinity sensor system with the use of molecular imprinted nanoparticles (plastic antibodies) to enhance the pesticide detection. Molecular imprinting based affinity sensor is prepared by the attachment of atrazine (chosen as model pesticide) imprinted nanoparticles onto the gold surface of SPR chip. Recognition element of the affinity sensor is polymerizable form of aspartic acid. The imprinted nanoparticles were characterized via FTIR and zeta-sizer measurements. SPR sensors are characterized with atomic force microscopy (AFM), scanning electron microscopy (SEM), Fourier transform infrared spectrophotometry (FTIR) and contact angle measurements. The imprinted nanoparticles showed more sensitivity to atrazine than the non-imprinted ones. Different concentrations of atrazine solutions are applied to SPR system to determine the adsorption kinetics. Langmuir adsorption model is found as the most suitable model for this affinity nanosensor system. In order to show the selectivity of the atrazine-imprinted nanoparticles, competitive adsorption of atrazine, simazine and amitrole is investigated. The results showed that the imprinted nanosensor has high selectivity and sensitivity for atrazine.

Development of surface plasmon resonance sensors based on molecularly imprinted nanofilms for sensitive and selective detection of pesticides

Pesticides have been utilized in agriculture for decades. However, their widespread use has increased multiple concerns due to their known and suspected toxicities on long-term human health risks in scientific and industrial communities. Thus, detecting pesticides will have a great impact on their management, as well as improve their toxicity effects over humans. Here, we fabricate molecularly imprinted nanofilms and integrate them with surface plasmon resonance (SPR) sensors for sensitive, selective, fast and real-time detection of multiple pesticides, including cyanazine (SNZ), simazine (SMZ) and atrazine (ATZ). The molecularly imprinted nanofilms onto the SPR gold surfaces are prepared via UV polymerization reactions, which consist of N-methacryloyl-l-phenylalanine methyl ester (MAPA) as a functional monomer, 1-vinylimidazole (VIM) as a co-monomer, and ethylene glycol dimethacrylate (EGDMA) as a cross-linker. The real-time measurements on SPR sensor provide a detection range from 0.10 to 6.64nM, as well as denote a limit of detection (LOD) values of 0.095, 0.031 and 0.091nM for SNZ, SMZ and ATZ, respectively. Furthermore, we perform selectivity test, where SNZ, SMZ and ATZ are examined as competitor agents. Overall, the pesticide imprinted SPR sensors have been found to be highly selective and sensitive. These SPR sensors also hold great potential to be used an alternative method for the existing pesticide monitoring approaches due to their reusability, fast response, and easy-to-use properties, as well as can be tailored to detect and real-time monitor of other pesticides.

Electrochemical Reduction of Atrazine at Carbon and Silver Cathodes

Since its introduction in the 1950s, atrazine (6-chloro-N2-ethyl-N4-(1-methylethyl)-1,3,5-triazine-2,4-diamine) has become one of the mostly widely used pesticides in the world. Although atrazine has been banned in the European Union since 2004, it is still applied extensively in the US, and can be detected in water sources, soil, and even air.1 Environmental persistence of atrazine and its metabolites has caused contamination to spread away from regions of herbicide application, and some studies have shown evidence of endocrine disruption in amphibians exposed to these chemicals.1 For these reasons, the degradation of atrazine to less environmentally harmful compounds is of great concern. In this study, we have employed electrochemical reduction for the degradation of atrazine at different cathode materials. Previous electrochemical studies of atrazine have been performed at mercury cathodes, and were successful in both the detection of atrazine by means of square-wave voltammetry and its degradation through controlled-potential (bulk) electrolyses.2-4 At mercury cathodes, long electrolyses resulted in both the breaking of the carbon–halogen bond and reduction of the triazine ring.4 To avoid the use of mercury, we have explored the use of carbon and silver cathodes; glassy carbon provides a simple, environmentally friendly alternative, whereas silver has been shown to be catalytic for the cleavage of carbon–halogen bonds. Reduction of atrazine at carbon and silver cathodes, respectively, in dimethylformamide (DMF) containing 0.050 M tetramethylammonium tetrafluoroborate (TMABF4), results in a single cyclic voltammetry peak at –1.77 or –1.62 V vs. a Cd(Hg) reference electrode. Investigations of the products arising from controlled-potential electrolysis by means of gas chromatography–mass spectrometry indicate the presence of dechlorinated atrazine (N2-ethyl-N4-(1-methylethyl)-1,3,5-triazine-2,4-diamine) after electrolyses at both carbon and silver cathodes.

Atrazine in public water supplies and risk of ovarian cancer among postmenopausal women in the Iowa Women's Health Study

BackgroundFew studies have evaluated environmental chemical exposures in relation to ovarian cancer. We previously found an increased risk of ovarian cancer among postmenopausal women in Iowa associated with higher nitrate...

Atrazine Detection in Liquid Using a Nanoimmunosensor Based on Chemically Modified Atomic Force Microscopy Tips

Atrazine Detection in Liquid Using a Nanoimmunosensor Based on Chemically Modified Atomic Force Microscopy Tips

Electrochemical Immunosensor for Detection of Atrazine Based on Polyaniline/Graphene

In this study, a novel layer-by-layer polyaniline/graphene (PANi/Gr) structure for electrochemical detection of atrazine was developed. Gr film was synthesized by thermal chemical vapor deposition (CVD) method and transferred onto the PANi-predeposited microelectrode. The properties of PANi/Gr film were thoroughly investigated by high-resolution transmission electron microscopy and Raman techniques. The most attractive feature of this system is a suitable microenvironment, which could provide an amplification of the conductive signal, thus may contribute to enhancing electron transfer and subsequently improve the sensitivity in electrochemical measurements. With low detection limit (∼ 43 × 10−12 g/L), acceptable stability and good reproducibility, the proposed electrochemical immunosensor could be advantageously extended for multiplexed detection of other agents of environmental pollution.

Polymeric Colloidal Nanostructures Fabricated via Highly Controlled Convective Assembly and Their Use for Molecular Imprinting.

In this work, the formation of various polystyrene (PS) colloidal structures on striped PS patterns is demonstrated based on a simple and novel convective assembly method that controls the electrostatic interactions between the PS colloidal particles and sodium dodecyl sulfate (SDS). Under the optimal conditions (different withdrawal speeds, channel dimensions, suspension concentrations, etc.), highly ordered structures such as highly close-packed, zigzag, and linear colloidal aggregates are observed. In addition, these colloidal arrangements are used for development of molecularly imprinted polymer (MIP) sensors with highly improved sensing properties. Using PDMS replicas, three hemispherical poly(methacrylic acid-ethylene glycol dimethacrylate) (poly(MAA-EGDMA)) MIP films, including planar MIP and non-imprinted polymer (NIP) films, are photopolymerized for detection of trace atrazine in an aqueous solution. From gravimetric quartz crystal microbalance (QCM) measurements, a non-close-packed MIP film exhibits highest sensing response (Δf = 932 Hz) to atrazine detection among hemispherical MIP films and shows 6.5-fold higher sensing response than the planar MIP film. In addition, the sensitivity of the MIP sensor is equivalent to -119 Hz/(mol L(-1)). From the ratio of slopes of the calibration curves for the hemispherical MIP and NIP films, the imprinting factor (If) is as high as 11.0. The hemispherical MIP film also shows excellent selectivity in comparison with the sensing responses of other analogous herbicides. As a result, this molecular surface imprinting using PS colloidal arrays is highly efficient for herbicide detection.

Surface plasmon resonance based optical fiber sensor for atrazine detection using molecular imprinting technique

We reported a successful effort for fabrication and characterization of surface plasmon resonance based fiber optic sensor to detect atrazine by molecular imprinted technique. The fabrication of sensing probe is done by coating a 40nm thick silver film over the unclad core of an optical fiber. Further, an over layer of molecular imprinted (MIP) polymer having atrazine as template molecule has been coated over Ag coated region. Spectral interrogation method has been used for characterization of the probe. A red shift of 38nm in resonance wavelength has been observed for atrazine concentration range of 0M–10−7M. Sensitivity of the sensor has been found to be 17.34nm/logM for atrazine concentration of 10−12M. The sensor has lowest detection limit of 1.92×10−14M and quantification limit of 7.61×10−14M. Sensor has been found to be highly selective as well as highly sensitive due to a combined approach of molecular imprinting and surface plasmon resonance. Besides them, sensor has numerous advantages such as low cost, fast response, immune to electromagnetic interface and capability of online monitoring and remote sensing.

Immunosensing of Atrazine with Antibody-Functionalized Cu-MOF Conducting Thin Films.

This work reports the assembly of thin films of a silica (SiO2)-modified copper-metal organic framework, Cu3(BTC)2 [Cu3(BTC)2@SiO2, BTC = benzene-1,3,5-tricarboxylic acid] on a conducting substrate of NH2-BDC [NH2-BDC = 2-aminobenzene-1,4-dicarboxylic acid] doped polyaniline (PANI). Assembled Cu3(BTC)2@SiO2/BDC-PANI thin films displayed electrical conductivity in the range of 35 μA. These thin films were conjugated with antiatrazine antibodies to create a novel immunosensing platform. Various structural and spectral characteristics of the synthesized material and its bioconjugate were investigated. The developed immunosensor was used for the conductometric sensing of atrazine. The detection of atrazine was achieved with a high sensor sensitivity (limit of detection = 0.01 nM) and specificity in the presence of diverse pesticides (e.g., endosulfan, parathion, paraoxon, malathion, and monochrotophos).

Inhibition-based biosensor for atrazine detection

This work presents an inhibition-based biosensor for the fast, simple and inexpensive determination of atrazine. The method is based on the inhibition of the enzyme tyrosinase from mushrooms (Tyr), immobilized on screen printed electrodes (SPEs). To optimize the biosensor performances several carbon based SPEs: graphite (G), graphene (GP), and multiwalled carbon nanotubes (MWCNTs) and immobilization techniques (physical and chemical) have been tested. Tyrosinase was immobilized on the electrode surface by either polyvinyl alcohol with styrylpyridinium groups (PVA-SbQ) as cross-linking agent or Nafion membranes as physical entrapment or bovine serum albumin with glutaraldehyde as chemical immobilization. In the presence of catechol as substrate, atrazine can be determined thanks to its inhibition activity towards the enzyme which catalyzes the oxidation of catechol to o-quinone. Under optimum experimental conditions, the best performance in terms of catalytic efficiency has been demonstrated by MWCNTs screen printed electrode with PVA-SbQ as immobilization method. The developed inhibition biosensor displays a linearity range towards atrazine within 0.5–20ppm, a LOD of 0.3ppm and acceptable repeatability and stability. This analysis method was applied to spiked drinking water samples with recoveries close to 95% respect to measurements carried out in PBS buffer. The low cost of this device and its good analytical performances suggest its application for the screening and monitoring of atrazine in real matrices.

Label-free disposable immunosensor for detection of atrazine

This work reports the construction of a fast, disposable, and label-free immunosensor for the determination of atrazine. The immunosensor is based on a field effect transistor (FET) where a network of single-walled carbon nanotubes (SWCNTs) acts as the conductor channel, constituting carbon nanotubes field effect transistors (CNTFETs). Anti-atrazine antibodies were adsorbed onto the SWCNTs and subsequently the SWCNTs were protected with Tween 20 to prevent the non-specific binding of bacteria or proteins. The principle of the immunoreaction consists in the direct adsorption of atrazine specific antibodies (anti-atrazine) to SWCNTs networks. After exposed to increasing concentrations of atrazine, the CNTFETs could be used as useful label-free platforms to detect atrazine. Under the optimal conditions, a limit of detection as low as 0.001ngmL−1 was obtained, which is lower than that of other methods for the atrazine detection, and in a working range between 0.001 and 10ngmL−1. The average recoveries obtained for real water samples spiked with atrazine varied from 87.3% to 108.0%. The results show that the constructed sensors display a high sensitivity and could be useful tools for detecting pesticides like atrazine at low concentrations. They could be also applied to the determination of atrazine in environmental aqueous samples, such as seawater and riverine water.

Microfluidic platform for environmental contaminants sensing and degradation based on boron-doped diamond electrodes.

We have developed a lab-on-a-chip (LOC) platform for electrochemical detection and degradation of the pesticide atrazine (Atz). It is based on boron-doped diamond (BDD) electrodes and a competitive magneto-enzyme immunoassay (EIA) that enables high sensitivity. To detect the enzymatic reaction, we employed a BDD electrode modified with platinum nanoparticles (PtNPs), as a highly conductive catalytic transducer. Chronoamperometry revealed a limit of detection (LOD) of 3.5 pM for atrazine, which, to the best of our knowledge, is one of the lowest value published to date. Finally, we degraded Atz in the same platform, using a bare BDD electrode that features remarkable corrosion stability, a wide potential window, and much higher O2 overvoltage as compared to conventional electrodes. These characteristics enable the electrode to produce a greater amount of HO• on the anode surface than do conventional electrodes and consequently, to destroy the pollutant more rapidly. Our new LOC platform might prove interesting as a smart system for detection and remediation of diverse pesticides and other contaminants.