Concentrations Of Profenofos Research Articles

Efficient removal of the organophosphate pesticide, profenofos using polymer-stabilized microporous Fe2O3-ZnO nanocomposite: Kinetic and thermodynamic analysis

In the contemporary landscape of scientific research, the development of inhibitors for acetylcholinesterase (AChE) holds significance due to their dual application as chemical warfare agents (CWAs) and pesticides. These compounds, whether intentionally deployed for malicious purposes, used in agriculture to combat pests, or accidentally released, pose a substantial threat to humanity. Consequently, there is a dire need to create efficient nanocatalysts capable of eliminating organophosphate toxic substances. This study focuses on the synthesis of a nanocomposite catalyst comprised of polymer-stabilized Fe2O3-ZnO, characterized as porous oval-shaped clusters that exhibit exceptional proficiency in the degradation of the pesticide profenofos (PF). This degradation process is remarkably swift, occurring within a short timeframe under both dark and light conditions. Porosity enhancement was achieved through the combination of polymeric stabilizing agents, namely polyvinylpyrrolidone (PVP) and methyl cellulose (MC). Notably, the highest concentration of profenofos (1825 mg/L) was directly introduced to the Fe2O3-ZnO nanocomposite catalyst. Remarkably, 100 % degradation was achieved within just 60 min in the absence of light, highlighting the feasibility of dark treatment as an effective degradation pathway. The kinetics of the reaction were evaluated using Lagergren pseudo-first order and Ho/McKay pseudo-second order kinetic models, employing varying catalyst doses and profenofos concentrations. The results indicated that the reaction predominantly follows second-order kinetics. Furthermore, thermodynamic parameters, including the change in Gibbs free energy (ΔG), entropy (ΔS), and enthalpy (ΔH), were assessed, revealing the spontaneous and exothermic nature of the reaction. Additionally, a proposed degradation pathway for the chemical warfare agent stimulant, profenofos, was elucidated. To our knowledge, this is the inaugural documentation showcasing the remarkable efficiency of a polymer-stabilized Fe2O3-ZnO nanocomposite catalyst in degrading the organophosphate pesticide, profenofos, achieving rapid degradation rates even under dark conditions. The findings contribute to the advancement of catalytic materials for environmental remediation and provide important insights into the kinetics, thermodynamics, and degradation pathways of organophosphate compounds.

An ultra-sensitive photoelectrochemical biosensing platform based on the AgVO3/BiOI heterojunction for an enzyme activity inhibition reaction.

An ultra-sensitive photoelectrochemical sensing platform for profenofos detection based on the inhibition of catalase activity was prepared in this work. First, the novel functional nanocomposite material AgVO3/BiOI was prepared by a hot solvent method and successive ion layer adsorption reaction. Then, chitosan was employed as a dispersion medium to disperse and immobilize the catalase. Under visible light irradiation, the prepared CAT/CS/AgVO3/BiOI/ITO nanocomposite electrode generates a stable low photocurrent in hydrogen peroxide solution. When this electrode is immersed in a phosphate buffer solution containing profenofos, the activity of the catalase is inhibited, resulting in an increase in the photocurrent. Under the optimized experimental conditions, the profenofos concentration and increase in photocurrent are linearly related in the concentration range of 1 × 10-10 to 5.0 × 10-8 mol L-1, and the limit of detection is 1.0 × 10-11 mol L-1. This biosensor shows good selectivity for detecting profenofos in fruits and vegetables, and the determination results of profenofos are satisfactory.

Highly Efficient Adsorption Characteristics and Mechanism of Nutshell Biochars for Aromatic Organophosphorus Insecticides

The wide use of the insecticide profenofos in crop production has led to serious ecological water problems in agricultural fields. With the increasing global production of nuts, a large amount of nutshell waste has a serious impact on the environment. Turning nutshell waste into biochar to remove high levels of profenofos in water is a cost-effective treatment method. In this study, biochars made from nutshell waste are investigated for the adsorption of aromatic organophosphorus insecticide profenofos. The adsorption amount of nutshell biochar was 13-fold higher than crop stalk biochar in removing profenofos from water. The results indicated that the adsorption of profenofos by nutshell biochar was specific. Scanning electron microscope (SEM) and Brunauer–Emmett–Teller (BET) analysis showed that nutshell biochars had a larger specific surface area and more microporous structures. Meanwhile, nutshell biochars could exhibit a stable adsorption capacity at different initial concentrations of profenofos (10–40 mg/L), temperature (298–318 K), and pH (3–7). Desorption and reuse experiments showed that profenofos was firmly bound to nutshell biochars in water and could be extracted from the biochars with acetonitrile. Within 10 times of recycling, nutshell biochar had a stable and strong adsorption capacity for profenofos. The adsorption process of profenofos by nutshell biochar was pore diffusion and surface adsorption, which is consistent with the pseudo second-order kinetic model and the Freundlich isotherm model. Elemental and Fourier transform infrared spectroscopy (FTIR) analyses showed that the adsorption mechanism of profenofos on nutshell biochar was mainly through π-π and hydrophobic interactions. Nutshell biochar also showed strong adsorption capacity for other aromatic organophosphorus pesticides, and the adsorption rates of methyl parathion, isocarbophos and 2-chloro-4-bromophenol were 85%, 73% and 73%, respectively. Nutshell biochar can serve as an excellent material for removing aromatic organophosphorus insecticide pollution from water.

Toxicity bioassay and sub-lethal effects of profenofos-based insecticide on behavior, biochemical, hematological, and histopathological responses in Grass carp (Ctenopharyngodon idella)

Profenofos (organophosphate) is among the major toxicant polluting freshwater bodies, exerting a significant effect on fish health. The LC50 value of Profenofos (PRO) was resolved in Grass carp (Ctenopharyngodon idella) with average body weight (55.82 ± 5.42 g) and determined the 96 h LC50 value as 7.2 µg/L for the assay. Twenty-one-day exposures to 1.8 µg/ L and 3.6 µg/ L doses were conducted to evaluate the sub-lethal effects, and various toxicological endpoints were assessed on the 1st, 7th, 15th and 21st days of exposure. Acute toxic stress was observed with fish displaying behavioral toxicity. The most hematological change was extreme microcytic hypochromic anemia. Leucocyte count increased in experimented fish. Moderate neutrophilia, monocytosis and lymphocytosis were observed. Serum total protein, albumin, and globulin concentrations were significantly diminished. Overall, increments over control were recognized in serum urea, creatinine and acid phosphatase. However, serum glucose, total lipid, cholesterol, serum ALT and AST activity showed a significant decrease in fish exposed to both concentrations of PRO. Serum IgM concentrations insignificantly changed in treated fish except for on the 21st day of exposure to 3.6 µg/ L of PRO, while serum lysozyme significantly decreased. Furthermore, total protein, lipid and glycogen concentrations in muscles and the liver exhibited a decreasing trend at all concentrations. Moreover, histopathological alterations in the liver, kidney, and muscles occurred exclusively after treatment. From the obtained results, it is assumed that profenofos induced general toxic impacts under field conditions and might disturb ecologically relevant processes.

In vitro Degradation of Profenofos by Rice Grain Rinse Water Lactic Acid Bacteria (LAB)

Widely used in fermentation industry, lactic acid bacteria (LAB) are not only probiotic but also capable of degrading pesticides. We evaluated in the laboratory degradation of profenofos 50% EC by the LAB present in rice grain rinse water cultured in LAB-specific de Mann Rogosa Sharpe (MRS) medium. A single colony of the isolated LAB was inoculated in MRS broth, kept in shaker for 24 h before 10 ml broth was transferred to 25 ml test tube inoculated with profenofos 50% EC at 1 ppm and checked 24, 48 and 72 h after inoculation for its residue by liquid-liquid extraction and gas chromatographic analysis. The results revealed that profenofos concentration decreased to 0.75, 0.44 and 0.25 ppm at 24, 48 and 72h, respectively, indicating the degradation of profenofos by the rice rinse water LAB.

Zn-ZrMOF containing Lewis acid-base catalytic sites for hydrolysis and visual detection of profenofos

A colorimetric method for the catalysis hydrolysis of profenofos (C11H15BrClO3PS) was designed based on Zn-ZrMOF. Zn-ZrMOF has the catalytic activity of organophosphorus hydrolase and contains Lewis acid-base catalytic sites, which can catalyze the cleavage of P-O bond of profenofos to obtain hydrolysate (4-bromo-2-chlorophenol). As a phenolic substance, 4-bromo-2-chlorophenol can react with the chromogenic agent 4-aminoantipyrine (4-AAP) and produce a pink product (4-((3-chloro-4-oxocyclohexa-2,5-dien-1-ylidene)amino)− 1,5-dimethyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one) in the presence of oxidizer K3[Fe(CN)6] under the weak alkalinity. The pink product has a strong UV absorption peak at 508 nm. The solution color gradually changed from colorless to pink with the increase of the concentration of profenofos. The concentration of profenofos could be semi-quantitatively analyzed by naked eye. The linear range of this method was 0.01–1000 μg mL−1, and the detection limit was 6.33 × 10−3 μg mL−1. Additionally, the method has good selectivity and accuracy for the determination of profenofos. This study provides a feasible strategy for the design of a metal-organic framework material with organophosphorus hydrolase-like catalytic activity for the determination of profenofos in vegetables.

Spectrophotometric Determination of Profenofos Using an Aptamer-Gold Nanorod (GNR)-Based Biosensor

A biosensor based on the optical signal of gold nanorods (GNRs) and an aptamer as the recognition element is reported to perform the rapid and selective spectrophotometric determination of profenofos. The GNR synthesized by the seed growth method have unique structures which binds with the aptamer through electrostatic adsorption and is well dispersed in a salt-containing solution. Upon the addition of profenofos, specific recognition caused aggregation of the GNRs. The optical signal therefore decreased and the response linearly related to the concentration of profenofos. The results demonstrate that ascorbic acid as the reducing agent plays an important role in the morphology of the GNRs. GNRs with the length-diameter ratio (L/D) of 12 stably combined with the aptamer. For the optimum conditions, spectrophotometric determination of profenofos was achieved using the biosensor with a linear relationship between the absorbance of GNR at 508 nm and the concentration of profenofos from 40 to 460 µg/L. The limit of detection of the method was 31.93 µg/L. In addition, this approach shows good selectivity for the analysis of fruits and vegetable. A valuable new method is reported for the determination of profenofos.

An efficient electrochemical sensing platform for profenofos detection

Profenofos is classified by the WHO as a moderately toxic pesticide (category II pesticide) for humans as it inhibits the acetylcholinesterase enzyme and causes respiratory distress. In this study, -NaCl-complexed crown ether was used to modify the Glassy Carbon Electrode (GCE) to detect the presence of profenofos in water at ultra-low level concentration. Differential pulse voltammetry was used to detect the target analyte at lower concentration with higher sensitivity. Suppression of charge transfer due to the ionic interaction between the positively charged sodium ion in NaCl-complexed crown ether and the negatively charged oxygen ion in O-ethyl S-propyl phosphorothioate results in the formation of NaCl•15-crown-5-O-ethyl S-propyl phosphorothioate. This in-turn inhibits the charge transfer process of [Fe(CN)6]3-/4-redox couple to the GCE, hence reducing the current density as a function of profenofos concentration. The profenofos sensor exhibits a wide linear range of 1.025–153.645 nM with a low detection limit of 0.341 nM and a sensitivity of 0.05 µA nM−1. And also, the developed sensor showed RSD, % of inhibition, and stability of <2.27%, <5%, 7 days, respectively. Owing to its stability, the sensor can be utilized for real-time testing of water quality.

Photodegradation of profenofos in aqueous solution by vacuum ultraviolet

Profenofos is a widely used organophophorous pesticide for several crops and is detected in drinking water sources. This study investigated the degradation of profenofos using vacuum ultraviolet (VUV) compared with ultraviolet (UV). The factors affecting the degradation performance including pH, profenofos concentration, bicarbonate, nitrate, nitrite, natural organic matter (NOM), and aeration were examined. Profenofos removal efficiencies were 84 % and 52 % by VUV and UV after 7 min of irradiation, respectively (Initial profenofos concentration of 2 mg/L). Degradation of profenofos by VUV were 3 times faster than UV. The degradation rates decreased with increasing initial profenofos concentration. Direct photolysis at 185 nm and OH• played major roles for profenofos removal by VUV. Aeration enhanced the profenofos degradation and mineralization by VUV but not UV. Bicarbonate inhibited the profenofos degradation while nitrate (≤50 mg-NO3-/L) acted as a photosensitizer enhancing profenofos degradation. NOM from groundwater and surface water sources also inhibited the profenofos removal by VUV as high as 39 % compared to deionized water. However, NOM promoted the profenofos removal by UV because degradation by OH• formed via NOM photolysis became the main degradation mechanism. The result of profenofos degradation under isolated NOM fractions elucidated that hydrophobic fractions had less inhibition compared to hydrophilic fractions. Identified products suggested that the pathway of profenofos photodegradation was the breaking of the OP bond and reduction of Br.

Determination of hormoligosis of organophosphate insecticides against Phenacoccus solenopsis.

Cotton mealybug is a highly invasive pest of agricultural crops worldwide. Major agriculturists most rely on the use of insecticides for the control of pesticides. So, the indiscriminate use of insecticides leads to resistance development in recent years. For this purpose, an experiment was conducted using different concentrations of the three insecticides (profenfos chlorpyrifos and triazophos) to check the hormoligosis effects against cotton mealybug (CMB) in laboratory conditions. Investigation of variations for % mortality of adults of CMB after three days revealed that all treatments had statistically significant (P ˂ 0.05). The highest mortality was observed at the highest concentrations of profenofos 2.4% (38.55%). After 7 days, all the treatments were significant with difference in means (P ˂ 0.05). The highest mortality was recorded at the highest dilution of pesticide profenofos 2.4% (77.11%). The values of fecundity and longevity exposed a valid difference among treatments (P ˂ 0.05). Maximum fecundity was observed at the concentration 2.4% (181.41%) and longevity showed (38.46%). The highest mortality was observed at a concentration of triazophos 4% (27.98%). For chlorpyriphos the highest mortality was examined at concentration 4% (24.79%). The fecundity showed a statistically significant difference for different concentrations of triazophos and chlorpyriphos (P ˂ 0.05). The results of the recent study provide valuable information regarding the selection of insecticides and hormoligosis effects. The study can be helpful in the implications of integrated pest management of P. solenopsis.

DEVELOPMENT AND OPTIMIZATION OF REACTION MEDIA AS AN EFFORT TO DETECT EXPOSURE TO PROFENOFOS TOXICITY WITH THE INDICATOR RHODAMINE 6G

Pesticides are potential chemicals widely used in the agricultural sector to tackle pests and plant diseases. However, pesticides, for instance, profenofos, can pose a risk of poisoning to farmers. It is necessary to prevent profenofos exposure through early detection using rhodamine 6G. The detection of the reaction between profenofos and rhodamine 6G requires an optimum medium. This study aimed to test the optimum medium to facilitate the reaction of profenofos and rhodamine 6G. Five media variations were utilized, including paper, hand plaster, panty liner, diaper, and hydrogel. The detection was performed by spraying profenofos at various concentrations, ranging from 100 to 400 ppm on respective media. The study adopted a rhodamine 6G and profenofos reaction sensitivity test on those five media. It applied both qualitative and quantitative analyses. The qualitative analysis aimed to observe various concentrations of profenofos based on the changes of colors on respective media, in which (+) marked the medium sensitivity while (-) indicated insensitivity. The quantitative analysis utilized a ultraviolet-visible spectrophotometry to measure the changes of colors based on the reaction of profenofos with rhodamine 6 G. Both qualitative and quantitative tests showed no changes of colors on paper, hand plaster, panty liner, and diaper. In contrast, hydrogel reflected the changes of colors based on the increasing concentrations of profenofos. The research recommends hydrogel as an optimum medium for the early detection of profenofos pesticide exposure.

Studying the effects of profenofos, an endocrine disruptor, on organogenesis of zebrafish.

Profenofos is an endocrine-disrupting chemical that can enter into the aquatic ecosystem either through surface runoff or through percolation of a toxicant from the soil. In order to clarify the effect of profenofos on the developmental stages of zebrafish, the embryos were treated with serial dilutions of profenofos (0%, 10%, 25%, and 50% of LC50). Embryos were treated with profenofos for 7 days or until hatching. The toxic endpoints assessed include hatching time, survival, malformation, and heartbeats of the embryos. In a 96-h test on zebrafish embryos, the LC50 of profenofos was 0.057 mg/L. Profenofos considerably lowered survival, increased abnormalities at different ontogenetic stages, and developed malformations of different organs in a concentration-dependent fashion. The identified developmental malformations were fluid accumulation, impaired jaw, short tail, ruptured pectoral and caudal fin, curved body, thin yolk sac tube, and deformed heart. The way of looping arrangement of the heart at the early stage of embryos was significantly influenced by the higher concentration of profenofos. Heartbeat is also reduced significantly in a concentration-dependent fashion. The results show that the zebrafish are susceptible to profenofos even at lower concentrations in the initial stage. Therefore, when used in agricultural areas adjacent to the aquatic environment, endocrine-disrupting chemicals should be used in an appropriate manner.

Acute toxicity of organophosphate pesticide profenofos, pyrethroid pesticide λ cyhalothrin and biopesticide azadirachtin and their sublethal effects on growth and oxidative stress enzymes in benthic oligochaete worm, Tubifex tubifex

The present study was aimed to assess the acute toxicity of organophosphate pesticide, profenofos; synthetic pyrethroid pesticide, λ cyhalothrin and biopesticide, azadirachtin and their sublethal effects on growth rate and oxidative stress biomarkers in Tubifex tubifex in vivo. The results showed that 96 h LC50 value of profenofos, λ cyhalothrin and azadirachtin to Tubifex tubifex are 0.59, 0.13 and 82.15 mg L−1 respectively. Pesticide treated worms showed several behavioral abnormalities including increased mucus secretion, erratic movements, wrinkling activity and decreased clumping tendency during acute exposure. The percentage of autotomy increased significantly (p < 0.05) with the increasing concentration of the pesticides at 96 h of exposure. Sublethal concentrations of profenofos (0.059 and 0.118 mg L−1), λ cyhalothrin (0.013 and 0.026 mg L−1) and azadirachtin (8.2 and 16.4 mg L−1) caused significant alterations in growth rate and oxidative stress enzymes in T. tubifex during 14 days exposure period. The growth rate of the pesticide exposed worms decreased significantly (P < 0.05) in a concentration and duration-dependent manner. Superoxide dismutase (SOD), reduced glutathione (GSH), glutathione-s-transferase (GST) and glutathione peroxidase (GPx) demonstrated a noteworthy (p < 0.05) initial induction followed by a subsequent reduction, while catalase (CAT) and malondialdehyde (MDA) exhibited noteworthy induction (p < 0.05) all through the exposure time. Through principal component analysis, correlation matrix, and integrated biomarker response, the effects of profenofos, λ cyhalothrin and azadirachtin on T. tubifex were distinguished. These results indicate that exposure to profenofos, λ cyhalothrin and azadirachtin affect survivability, change the behavioral responses, reduce the growth rate and induce oxidative stress enzymes in T. tubifex.

Photoresponsive Surface Molecularly Imprinted Polymers for the Detection of Profenofos in Tomato and Mangosteen.

As a moderately toxic organophosphorus pesticide, profenofos (PFF) is widely used in agricultural practice, resulting in the accumulation of a high amount of PFF in agricultural products and the environment. This will inevitably damage our health. Therefore, it is important to establish a convenient and sensitive method for the detection of PFF. This paper reports a photoresponsive surface-imprinted polymer based on poly(styrene-co-methyl acrylic acid) (PS-co-PMAA@PSMIPs) for the detection of PFF by using carboxyl-capped polystyrene microspheres (PS-co-PMAA), PFF, 4-((4-(methacryloyloxy)phenyl)diazenyl) benzoic acid, and triethanolamine trimethacrylate as the substrate, template, functional monomer, and cross-linker, respectively. PS-co-PMAA@PSMIP shows good photoresponsive properties in DMSO/H2O (3:1, v/v). Its photoisomerization rate constant exhibits a good linear relationship with PFF concentration in the range of 0~15 μmol/L. PS-co-PMAA@PSMIP was applied for the determination of PFF in spiked tomato and mangosteen with good recoveries ranging in 94.4–102.4%.

Rapid biodegradation and biofilm-mediated bioremoval of organophosphorus pesticides using an indigenous Kosakonia oryzae strain -VITPSCQ3 in a Vertical-flow Packed Bed Biofilm Bioreactor.

The widespread use of pesticides has been one of the major anthropogenic sources of environmental pollution. Organophosphorus (OP) pesticides are predominantly used in agriculture due to their broad-spectrum insecticidal activity and chemical stability. The study was focused on the biodegradation of OP pesticides, Profenofos (PF) and Quinalphos (QP) in culture media using bacterium isolated from wetland paddy rhizosphere. The strain VITPSCQ3 showed higher pesticide tolerance, efficient biofilm formation and was capable of synthesizing organophosphate degrading enzymes. Based on the 16S rRNA gene sequencing the isolate exhibited maximum sequence similarity with Kosakinia oryzae (GenBank accession number: KR149275). Biodegradation assay with various concentrations of PF and QP (200, 400, 600 and 800mgL-1) showed maximum degradation up to 82% and 92% within 48h. The kinetic studies revealed the biodegradation rates (k) to be 0.0844 min-1 and 0.107 min-1 with half-lives (h) of 18h and 14.8h for PF and QP. The degradation products were identified by GCMS and possible degradation pathways were proposed using Insilico techniques. To the best of our knowledge, this is the first report on the biodegradation of PF and QP using Kosakonia oryzae. Bioremoval of PF and QP from aqueous solution was performed using the biofilm of VITPSCQ3 developed on selected substrates in a circulating Vertical-flow packed-bed biofilm (VFPBB) bioreactor. Charcoal, gravel and mushroom (Agaricus bisporus) were used as biofilm carriers. Mushroom showed strong biofilm formation with optimum biodegradation capacity of up to 96% for PF and 92% for QP within 120min reaction time.

Histopathological Changes in the Kidney of the Freshwater Bronze Featherback Fish, Notopterus notopterus (Pallas, 1769) Exposed to Profenofos

The impact of profenofos, an organophosphate pesticide on the kidney of Indian freshwater teleost fish Notopterus notopterus was evaluated. The experimental group was exposed to sublethal concentration of profenofos at 7, 14 and 21 days. Histopathological changes due to the toxicity of pesticide in experimental and control kidney of the fish were observed by killing the animal every 7, 14 and 21 days. The kidneys were fixed in Bouin’s solution, dehydrated in graded ethanol, infiltrated in xylene, sectioned at 4-6 µ and stained in haematoxylin and eosin. Haemorrhage, oedema, fragmented glomeruli and elongated kidney tubules in experimental fish, and no effect were however observed in control fishes. It is concluded that profenofos is significantly toxic to the fish.

Degradation of pesticide residue in ‘Mahajanaka’ mango fruit during storage at different conditions

The degradation of pesticide in mango 'Mahajanaka' from Wiang Nong Long district, Lumphun province, was studied. Profenofos and carbaryl residue of mango fruits was measured after dip in profenofos + carbaryl in 500 and 850 mg L-1, respectively. The results found that at 25°C profenofos degraded faster than at 5 and 13°C. The concentrations of profenofos were 0.23, 0.29 and 0.46 mg kg-1 after dip in pesticide at 6, 15 and 18 days, respectively. The carbaryl residue was non-detectable in the mango stored at 13 and 25°C for 3 days, while in the stored mango in 5°C, 0.13 mg kg-1 of the residue was still detected, which is lower than the MRL of Thai Agricultural Standard, established by the National Bureau of Agricultural Commodity and Food Standards.

Detection of oxidative stress and DNA damage in freshwater snail Lymnea leuteola exposed to profenofos

Extensive production and use of organophosphate pesticide in agriculture, has risen concerned about its ecotoxicity and risk assessment of insecticides, which are more important. Therefore, the present investigation was aimed to study the induction of oxidative stress and DNA damage by organophosphate insecticide profenofos (PFF) in freshwater snail Lymnea luteola (L. luteola). The median lethal value (96 h LC50) of PFF was estimated as 1.26 mg/L for L. luteola in a semi-static system and on the basis of LC50 value three concentrations viz., 0.126 (1/10 of LC50, Sublethal I), 0.63 (1/2 of LC50, Sublethal II) and 0.84 mg/L (2/3 of LC50, Sublethal III) were determined. Snails were exposed to above-mentioned concentrations of PFF along with solvent control (acetone) and negative control for 96 h. The haemolymph was collected at 24 and 96 h of after treatment. In heamolymph of PFF exposed snail, lipid peroxide, glutathione reduced glutathione S transferase and superoxide dismutase activities at the tested concentrations significantly differ from those in the control. The genotoxicity induced in hemocytes of treated snails was measured by alkaline single cell gel electrophoresis assay. The data of this experiment demonstrated significantly enhancement of oxidative stress and DNA damage in the treated snails as compared to controls. Also, we observed statistically significant correlations of ROS with DNA damage (% tail DNA) (R2 = 0.9708) for 24 h and DNA damage (R2 = 0.9665) for 96 h. Results of the current experiment can be useful in risk evaluation of PFF among aquatic organisms. The study confirmed the use of comet assay for in vivo laboratory experiments using freshwater snail for selecting the toxic potential of industrial chemicals and environmental contaminants.

Aptamer-based microcantilever-array biosensor for profenofos detection

Profenofos, a highly poisonous organophosphorus pesticide, has been widely used in agricultural production. These pesticide residues have seriously influenced food security and threatened human health, and new methods with high sensitivity are greatly needed to detect profenofos. Here, we developed an aptamer-based microcantilever-array sensor operated in stress mode to detect profenofos, with advantages of being a label-free, highly sensitive, one-step immobilization method capable of quantitative and real-time detection. The microcantilevers were functionalized with a profenofos-specific aptamer (SS2-55), and then the specific binding of profenofos to aptamer induced a deflection of the microcantilever, which was monitored using an optical method in a real-time manner. The microcantilever deflection showed a positive relationship with profenofos concentration, and the detection limit was low to 1.3 ng mL−1 (3.5 nM) for profenofos, which was much lower than other aptamer-based detection methods. The selectivity of the sensor was verified with another organophosphorus pesticide. Additionally, we successfully detected profenofos dissolved in vegetable-soak solution. Our results showed that this aptamer-based microcantilever-array sensor is a convenient and label-free method for detecting profenofos in small amounts and has great potential for food-security applications.

Extractive separation of Profenofos as an organophosphorous insecticide from wastewater and plant samples using molecular imprinted cellulose

A new selective molecular imprinted polymer (MIP) for solid phase extraction of profenofos (PFF) from aqueous solutions was synthesized by acrylonitrile grafted cotton fibers with hydrazine hydrate in presence of PFF as a template and glutraldhyde as a cross linker. The properties and structure of MIP was confirmed using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and elemental analysis (EA). Furthermore, the extracted PFF was detected by gas chromatography (GC). Various parameters such as (pH, contact time, temperature, initial concentration of PFF and also washing eluent composition) affecting the extraction efficiency was evaluated to investigate the selectivity and preconcentration from different matrices. Kinetic studies revealed that pseudo second order kinetic equation is the best model describes the adsorption behavior of PFF on MIP. Moreover, the obtained thermodynamic parameters (ΔG0<0, ΔH0>0, ΔS0>0) indicated a spontaneous and endothermic reaction. Furthermore, the maximum sorption capacity was 17.24mgg−1. Under the experimental work conditions, limit of detection and limit of quantification were found to be 0.294mgL−1 and 0.98mgL−1, respectively. Finally, the proposed imprinted polymer was successfully applied for the extraction of PFF from wastewater and commercial plant samples. The recoveries of PFF were in the range between 94 and 104% with relative standard deviations (RSD) less than 5.0%.