Rapid and specific detection of thiabendazole: enzymatic digestion-enabled fluorescent aptasensor

Thiabendazole, a widely used broad-spectrum fungicide in agriculture, poses risks to human health. To monitor its presence in water, we propose a fluorescent aptasensor utilizing Escherichia coli exonuclease I (Exo I). The findings demonstrate a linear correlation between thiabendazole concentrations and digestion percentage, with a detection limit (LOD) exceeding 1 µM and a determination coefficient (R2) of 0.959. This aptamer-based fluorescence spectroscopy detection system holds promise for a rapid, specific, and sensitive analysis of thiabendazole in environmental waters and food matrices.

Antifungal drugs in the aquatic environment: A review on sources, occurrence, toxicity, health effects, removal strategies and future challenges

Fungal infections pose a significant global health burden, resulting in millions of severe cases and deaths annually. The escalating demand for effective antifungal treatments has led to a rise in the wholesale distribution of antifungal drugs, which consequently has led to their release into the environment, posing a threat to ecosystems and human health. This article aims to provide a comprehensive review of the presence and distribution of antifungal drugs in the environment, evaluate their potential ecological and health risks, and assess current methods for their removal. Reviewed studies from 2010 to 2023 period have revealed the widespread occurrence of 19 various antifungals in natural waters and other matrices at alarmingly high concentrations. Due to the inefficiency of conventional water treatment in removing these compounds, advanced oxidation processes, membrane filtration, and adsorption techniques have been developed as promising decontamination methods.In conclusion, this review emphasizes the urgent need for a comprehensive understanding of the presence, fate, and removal of antifungal drugs in the environment. By addressing the current knowledge gaps and exploring future prospects, this study contributes to the development of strategies for mitigating the environmental impact of antifungal drugs and protecting ecosystems and human health.

Highly efficient adsorption and mechanism of alkylphenols on magnetic reduced graphene oxide

The influence of alkylphenols to environment cannot be ignored, as they are common product from chemical industries and potential threat to human health. Some alkylphenols are listed as persistent toxic substances (PTS) by the United Nations Environment Programme (UNEP). In this study, the optimized magnetic reduced graphene oxide (MrGO) was synthesized by a facile solvothermal method, and investigated for adsorption of three typical alkylphenols. In neutral condition, MrGO showed extremely high adsorption capacity of three typical alkylphenols, 4-heptylphenol (4-HP), 4-tert-octylphenol (4-OP), and 4-nonylphenol (4-NP), which could reach 938.9 mg g^-1 (40 °C), 987.8 mg g^-1 (40 °C), and 989.7 mg g^-1 (20 °C), respectively. This study revealed that the adsorption process was a heterogeneous multi-layer physical adsorption, and the adsorption rates were related to the number of unoccupied vacancies on the adsorbent surface. From batch experiments and density functional theory (DFT) calculations, the main adsorption interactions between MrGO and alkylphenols were deduced to be π-π, hydrogen-bond, and hydrophobic interactions. What's more, the different affinities of MrGO towards different targets were further distinguished and explained in detail. The wonderful stability and recyclability of MrGO made it a promising cost-effective remediation candidate.

Fluorescence enhancement of fungicide thiabendazole by van der Waals interaction with transition metal dichalcogenide nanosheets for highly specific sensors

Many molecules quench their fluorescence upon adsorption on surfaces. Herein we show that the interaction of thiabendazole, a widespread used fungicide of the benzimidazole family, with nanosheets of transition metal dichalcogenides, particularly of WS2, leads to a significant increase, more than a factor of 5, of the fluorescence yield. This surprising effect is rationalized by DFT calculations and found to be related to the inhibition of the intramolecular rotation between the benzimidazole and thiazole groups due to a bonding rigidization upon interaction with the MoS2 surface. This non-covalent adsorption leads to a redistribution of the molecular LUMO that blocks the non-radiative energy dissipation channel. This unusual behaviour does not operate either for other molecules of the same benzimidazole family or for other 2D materials (graphene or graphene oxide). Moreover, we found that a linear dependence of the emission with the concentration of thiabendazole in solution, which combined with the specificity of the process, allows the development of a highly sensitive and selective method towards thiabendazole determination that can be applied to real river water samples. An excellent detection limit of 2.7 nM, comparable to the best performing reported methods, is obtained with very good accuracy (Er ≤ 6.1%) and reproducibility (RSD ≤ 4.1%) in the concentration range assayed.

Interaction Between Metarhizium anisopliae (Met.) and the Insecticides Used for Controlling House Fly (Diptera: Muscidae) in Poultry Farm of Malaysia

The potential of integrating the mycoinsecticide, Metarhizium anisopliae (Met.), into house fly control programs is tremendous. However, the interaction between the fungus and insecticide, when applied at poultry farms, remains poorly understood. This study investigated the interaction between M. anisopliae and two selected insecticides, cyromazine and ChCy (a mixture of chlorpyrifos and cypemethrin), with three objectives: to assess the compatibility of M. anisopliae and the insecticides by measuring fungal vegetative growth and conidia production in the presence of insecticides; to evaluate the effect of M. anisopliae on these insecticides by analyzing insecticidal residue using ultra performance liquid chromatography; and to study the synergistic effects of M. anisopliae and the insecticides by applying sublethal concentrations of insecticides with M. anisopliae to house fly larvae. Metarhizium anisopliae was more tolerant to ChCy than to cyromazine, as M. anisopliae showed significantly more growth when grown with this insecticide. The M. anisopliae + ChCy combination resulted in significantly less chlorpyrifos residues compared to the ChCy plate, and 62-72% house fly larva mortality occurred when M. anisopliae and sublethal concentrations of ChCy were combined, implicating synergistic effects of the fungus with low concentrations of ChCy. Integrating M. anisopliae with compatible chemical at right concentration is crucial for poultry farm house fly control programs.

Fast determination of pesticides and other contaminants of emerging concern in treated wastewater using direct injection coupled to highly sensitive ultra-high performance liquid chromatography-tandem mass spectrometry

It is well known that wastewater treatment plant (WWTP) effluents usually contain micropollutants such as pharmaceuticals (or their transformation products, TPs) or pesticides, which is a major issue when evaluating their possible reuse (e.g. for irrigation in agriculture). In search for an improved accuracy and simplicity, methods based on the direct injection of the sample (DI) represent a recent trend taking advantage of the increasing sensitivity of new mass spectrometry (MS) instruments. Thus, the present study shows the development and validation of a DI-based method by ultra-high-performance liquid chromatography quadrupole-linear ion trap analyser (UHPLC-QqLIT-MS/MS). The proposed method was applied to the monitoring of 115 organic microcontaminants (including pharmaceuticals, TPs and pesticides) at the ngL^-1/μgL^-1 level in wastewater effluents from urban WWTPs. Sample pre-treatment was reduced to acetonitrile addition and filtration of the mixture previous to LC-MS analysis. Total analysis time was <15min. A subsequent validation protocol was carried out in treated WW (TWW), following indications of SANTE and Eurachem Guidelines. Linearity and matrix effect were evaluated in the range of 10-1000ngL^-1. 70% of the analytes showed a moderate matrix effect (≤25%). Trueness (expressed as recovery) and precision (calculated as relative standard deviation, RSD) were evaluated at four concentration levels (20, 50, 500 and 1000ngL^-1) in TWW samples. The LODs ranged from 1 to 357ngL^-1 and the LOQs from 10 to 500ngL^-1. 92% of the compounds showed limits of quantification ≤100ngL^-1. In most cases, mean recoveries were in the range 70-120%, and RSD values were ≤20%. The validated method was successfully applied to the analysis of 10 TWW samples, demonstrating the occurrence of 67 target compounds at concentration levels from 26705ngL^-1 (4-aminoantipyrine) to 10ngL^-1 (tebuconazole and bezafibrate).

Degradation of Insecticides in Poultry Manure: Determining the Insecticidal Treatment Interval for Managing House Fly (Diptera: Muscidae) Populations in Poultry Farms

It is crucial to understand the degradation pattern of insecticides when designing a sustainable control program for the house fly, Musca domestica (L.), on poultry farms. The aim of this study was to determine the half-life and degradation rates of cyromazine, chlorpyrifos, and cypermethrin by spiking these insecticides into poultry manure, and then quantitatively analyzing the insecticide residue using ultra-performance liquid chromatography. The insecticides were later tested in the field in order to study the appropriate insecticidal treatment intervals. Bio-assays on manure samples were later tested at 3, 7, 10, and 15 d for bio-efficacy on susceptible house fly larvae. Degradation analysis demonstrated that cyromazine has the shortest half-life (3.01 d) compared with chlorpyrifos (4.36 d) and cypermethrin (3.75 d). Cyromazine also had a significantly greater degradation rate compared with chlorpyrifos and cypermethrin. For the field insecticidal treatment interval study, 10 d was the interval that had been determined for cyromazine due to its significantly lower residue; for ChCy (a mixture of chlorpyrifos and cypermethrin), the suggested interval was 7 d. Future work should focus on the effects of insecticide metabolites on targeted pests and the poultry manure environment.

Use of micellar liquid chromatography for rapid monitoring of fungicides post harvest applied to citrus wastewater

A method based on micellar liquid chromatography has been developed to simultaneously monitor four pesticides largely post-harvest applied to citrus: thiabendazole, pyrimethanil, o-phenylphenol and imazalil. Water samples were filtered and directly injected without other treatment, thus avoiding extraction steps. The composition of the mobile phase was optimized using a chemometrical approach to achieve and excellent resolution to 0.07 mol/L SDS/5%, V/V 1-pentanol buffered at pH3. Mobile phase run through a C18 column at 1 mL/min at room temperature. The detection was performing by UV-Visible absorbance using a wavelength program: 0-10 min, 305 nm (for thiabendazole); 10-12; 265 nm (for pyrimethanil) and 12-18, 220 nm (o-phenylphenol and imazalil). The developed method was validated following the guidelines of the US Environmental Protection Agency in terms of: quantitation range, (0.5-4 to 15 μg/mL), linearity (r(2)>0.9995), sensitivity (LOD, 0.18-1.4 μg/mL), precision (<9.2%), trueness (93.9%-103.7%), and ruggedness (<9.9%). It was found that the fungicides remain up to eight days in surface water at outdoor conditions. The method was used to screen the presence of the analytes in several waste water samples, and was proved to be useful in routine analysis.

Electrochemical sensors of octylphenol based on molecularly imprinted poly(3,4-ethylenedioxythiophene) and poly(3,4-ethylenedioxythiophene–gold nanoparticles)

Two molecularly imprinted electrochemical sensors are fabricated by using EDOT and EDOT–AuNPs as monomers, respectively. The sensors show good analytical performance for OP sensing. Note: graphene nanoribbons (GNRs), 3,4-ethylenedioxythiophene (EDOT), 4-tert-octyl-phenol (OP).