Search Results (32)

Luminescent metal–organic frameworks (MOFs) are used for the detection of organophosphorus pesticides (OPs) due to their large surface area and pore volume as well as their special optical properties. However, most self-luminescent MOFs are not only complex to synthesize and unstable in water but also feature a “turn-off” sensing system, which has highly restricted their practical applications in OP detection. Herein, a “turn-on” fluorescence sensor based on the guest-induced luminescence MOF Ru(bpy)₃²⁺@UiO-66 was constructed, which realized the sensitive detection of OPs through a dual-enzyme system for the first time. Compared with self-luminescent MOFs, Ru(bpy)₃²⁺@UiO-66 was not only more easily synthesized but also had higher chemical and photostability in water. In this strategy, by means of the hydrolysis of AChE and ChOx, H₂O₂ will be produced, which can oxidize Fe²⁺ to Fe³⁺, thereby quenching the fluorescence of Ru(bpy)₃²⁺@UiO-66. In the presence of OPs, the activity of AChE can be inhibited, resulting in the inability to generate H₂O₂ and Fe³⁺, which will turn on the fluorescence signal of Ru(bpy)₃²⁺@UiO-66. As a result, the Ru(bpy)₃²⁺@UiO-66 sensing system not only had high sensitivity for OPs detection but also possessed a satisfactory detection recovery rate for parathion-methyl in real samples, which provides a new approach for OP detection in food safety as well as environmental monitoring. Full article

In this study, we present a novel surface-enhanced Raman scattering (SERS) substrate based on porous silicon microcavities (PSiMCs) decorated with silver nanoparticles (AgNPs) for ultra-sensitive molecule detection. This substrate utilizes a dual enhancement mechanism: the localized surface plasmon resonance (LSPR) of AgNPs and the optical resonance of the PSiMC structure, which together create intense electromagnetic hot spots and prolong photon–molecule interactions. The porous architecture provides a large surface area for uniform nanoparticle distribution and efficient analyte adsorption. The AgNP/PSiMC substrate demonstrates an impressive detection limit of 1.0 × 10⁻¹³ M for rhodamine101 and 1.0 × 10⁻¹⁰ M for methyl parathion, outperforming many previously reported SERS platforms. Furthermore, the substrate exhibits excellent signal uniformity (RSD ≈ 6.14%) and long-term stability, retaining over 50% signal intensity after 28 days. These results underscore the potential of AgNP/PSiMCs as highly efficient, reproducible, and scalable SERS platforms for trace-level chemical and environmental sensing applications. Full article

In this study, C18-functionalized magnetic silica nanoparticles (Fe₃O₄@SiO₂@C18) were used as adsorbents for the magnetic solid-phase extraction (MSPE) of organic contaminants commonly applied to aquaculture water (organic booster biocides, herbicides, and insecticides) followed by Gas Chromatography coupled to Mass Spectrometry (GC–MS). The extraction conditions and efficiency of the nanoparticles for the determination of ten pesticides (atrazine, ethoxyquine, chlorothalonil, chlorpyriphos methyl, methyl parathion, chlorpyriphos, resmethrin, λ-cyhalothrin, permethrin, and irgarol) were thoroughly investigated. Several experimental parameters affecting the extraction efficiency such as the amount of sorbent, extraction time, and elution time were optimized by employing experimental designs as response surface methodology. Validation experiments showed that the average recoveries of target analytes were in the range of 60% to 99%. The optimized method exhibited good linearity (R² > 0.9901) and satisfactory precision (Relative Standard deviations, RSDs < 15%). The method detection limits ranged between 1.9 ng L⁻¹ and 62 ng L⁻¹. Finally, the MSPE method was successfully applied to aquaculture water samples collected from the Thesprotia region (N.W. Greece), Thermaikos Gulf (N. Greece) and Butrint (S.W. Albania). Full article

Widespread use of pesticides in agriculture causes adverse impacts on non-target organisms and environmental pollution. Efficient and sustainable pesticide removal alternatives must be developed to reduce pesticide environmental impacts. Recently, bioremediation based on immobilized microorganisms has been proposed as an environmentally friendly and cost-effective approach for pesticide degradation in water. Agro-industrial wastes are produced in large quantities in crop fields; their high availability, low cost, and potential for reuse make them ideal support materials for microbial immobilization. This systematic review, conducted through the PRISM 2020 methodology, compiles recent research on using agro-industrial waste to immobilize microorganisms for pesticide degradation. The identified studies highlight corn straw as the most studied agro-industrial waste, while the organophosphorus insecticides, chlorpyrifos, and methyl parathion were the most representative pesticides; in the identified studies, pesticide degradation was conducted mainly by bacteria of the Acinetobacter, Bacillus, and Pseudomonas genera. Overall, microbial immobilization significantly enhanced pesticide degradation, rendering it a viable bioremediation strategy for pesticide-contaminated water. Full article

TiO₂ thin film coatings significantly improve catalyst separation in photocatalytic processes. They can be applied in heterogeneous photocatalysis under sunlight by mixing TiO₂ with other oxides, such as CeO₂, for the removal of pollutants in water. Here, TiO₂-CeO₂ thin films deposited on borosilicate slides were analyzed and applied in solar heterogeneous photocatalysis for the oxidation of pesticides. The films were synthesized by the sol-gel method with spin coating. The waste solutions from the synthesis were used to prepare TiO₂ and TiO₂-CeO₂ powders. These were analyzed by XRD and XPS to explain the behavior of the films. The thin films were characterized by UV-Vis spectroscopy with transmittance, UV-Vis spectroscopy with RDS, profilometry, AFM and SEM. The addition of CeO₂ to TiO₂ caused a decrease in the average crystal size and an increase in the strain index. The addition of a second layer made the TiO₂-CeO₂ thin films thinner. The CeO₂ created surface and electronic defects in the titania films, which enhanced their photocatalytic properties under sunlight in the mineralization of diuron and methyl parathion. The TiO₂-CeO₂-5.0% single-layer thin film samples were the most active in this study and will undoubtedly be applied in larger-scale reaction systems. Full article

In this study, we tested the insectistatic and insecticidal effects of the ethanolic extract of stems and bark of Ficus petiolaris Kunth (Moraceae) in laboratory bioassays with an artificial diet against newly hatched larvae of the fall armyworm, Spodoptera frugiperda Smith (Lepidoptera: Noctuidae). The extract was evaluated at five different concentrations (500, 1000, 1500, 2000, and 2500 ppm). The 2500 ppm extract had the strongest inhibitory effects on larval (89%) and pupal (20%) weight as well as the highest mortality (80%). The positive control, methyl parathion (Methyl Parathion^®) at 1%, eliminated 100% of the fall armyworm, and the negative control (artificial diet) had a mortality of only 5%. Chemical fractionation of F. petiolaris stem and bark extract produced five fractions of FpR1-5, each of which was evaluated at 250, 500, 750, 1000, and 1250 ppm. FpR4 presented the strongest inhibitory effect, reducing the weight of the larva and pupa by 35% and 18%, while FpR2 had the strongest insecticidal effect, with 90% mortality at 1250 ppm. The pure 8-Methoxypsoralen compound extracted from this fraction was even more effective, with 100% S. frugiperda mortality at 100 ppm. The 50% lethal concentration (LC₅₀) of 8-Methoxypsoralen was 67.68 ppm. Our results indicate that the F. petiolaris extract showed toxic activity against the fall armyworm, and its compound 8-Methoxypsoralen showed strong insecticidal activity at low concentrations. Full article

Gd/Fe-SnO₂ nanopowders as novel photocatalysts for the active removal of Rose Bengal dye and methyl parathion pesticide were synthesized with a low-cost coprecipitation route. The X-ray diffraction analysis of SnO₂, Sn_0.96Gd_0.02Fe_0.02O₂ and Sn_0.94Gd_0.02Fe_0.04O₂ nanopowders proved the formation of a tetragonal phase of tin oxide with average crystallite sizes in the range of 13–18 nm. The Fourier transform infrared (FTIR) spectra of all samples displayed the characteristic absorption bands of SnO₂. The nanopowder of the pure SnO₂ sample, as seen in its transmission electron microscope (TEM) image, contains spherical-like particles of variable sizes. The TEM images of the Sn_0.96Gd_0.02Fe_0.02O₂ and Sn_0.94Gd_0.02Fe_0.04O₂ powders revealed the synthesis of fine spherical nanoparticles. Based on the TEM images, the average particle size of the pure, (Gd, 2 wt% Fe) and (Gd, 4 wt% Fe) codoped SnO₂ nanopowders was estimated to be 14, 10 and 12 nm, respectively. After the addition of (Gd, 2 wt% Fe) and (Gd, 4 wt% Fe) to the SnO₂ structure, the band gap energy of SnO₂ was reduced from 3.4 eV to 2.88 and 2.82 eV, respectively. Significantly, the Sn_0.96Gd_0.02Fe_0.02O₂ nanocatalyst exhibited a high removal efficiency of 98 and 96% for Rose Bengal dye and methyl parathion pesticide after activation by sunlight for 35 and 48 min, respectively. Furthermore, this catalyst has shown perfect mineralization as well as high stability properties for the treatment of Rose Bengal dye and methyl parathion pesticide. These results suggest the suitability of the Sn_0.96Gd_0.02Fe_0.02O₂ nanocatalyst for the treatment of agriculture and industrial effluent under sunlight light energy. Full article

A new catalyst, Sm₂NdSbO₇, was synthesized for the first time by solid-phase sintering. The study utilized X-ray diffraction, transmission electron microscope energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy to examine the structural characteristics of monocrystal BiDyO₃, monocrystal Sm₂NdSbO₇ and Sm₂NdSbO₇/BiDyO₃ heterojunction photocatalysts (SBHP) prepared by solid-phase sintering. The Sm₂NdSbO₇ photocatalyst owned a pyrochlorite structure, belonged to the face-centered cubic crystal system, possessed a space group of Fd3m and a bandgap width of 2.750 eV. After 145 min of visible light irradiation (145-VLIRD), the removal rate (RMR) of methyl parathion (MP) or total organic carbon of SBHP was 100% or 97.58%, respectively. After 145-VLIRD, the photocatalytic degradation rates of SBHP to MP were 1.13 times, 1.20 times, and 2.43 times higher than those of the Sm₂NdSbO₇ photocatalyst, the BiDyO₃ photocatalyst, and the nitrogen-doped TiO₂ catalyst, respectively. The experimental results showed that SBHP had good photocatalytic activity. After four cycles of cyclic degradation experiments with SBHP, the elimination rates of MP were 98.76%, 97.44%, 96.32%, and 95.72%, respectively. The results showed that SBHP had good stability. Finally, the possible degradation pathways and degradation mechanisms of MP were speculated. In this study, we successfully developed a high-efficiency heterojunction catalyst which responded to visible light and possessed significant photocatalytic activity. The catalyst could be used in photocatalytic reaction system for eliminating the harmful organic pollutants from wastewater. Full article

An unprecedented photocatalyst, Sm₂EuSbO₇, was successfully fabricated in this paper, through a high-temperature solid-state calcination method, which represented its first ever synthesis. Additionally, using the solvothermal method, the Sm₂EuSbO₇/ZnBiSbO₅ heterojunction photocatalyst (SZHP) was fabricated, marking its debut in this study. XRD analysis confirmed that both Sm₂EuSbO₇ and ZnBiSbO₅ exhibited pyrochlore-type crystal structures with a cubic lattice, belonging to the Fd3m space group. The crystal cell parameter was determined to be 10.5682 Å or 10.2943 Å for Sm₂EuSbO₇ or ZnBiSbO₅, respectively. The band gap width measured for Sm₂EuSbO₇ or ZnBiSbO₅ was 2.73 eV or 2.61 eV, respectively. Under visible light irradiation for 150 min (VLTI-150 min), SZHP exhibited remarkable photocatalytic activity, achieving 100% removal of parathion methyl (PM) concentration and 99.45% removal of total organic carbon (TOC) concentration. The kinetic constant (k) for PM degradation and visible light illumination treatment was determined to be 0.0206 min⁻¹, with a similar constant k of 0.0202 min⁻¹ observed for TOC degradation. Remarkably, SZHP exhibited superior PM removal rates compared with Sm₂EuSbO₇, ZnBiSbO₅, or N-doped TiO₂ photocatalyst, accompanied by removal rates 1.09 times, 1.20 times, or 2.38 times higher, respectively. Furthermore, the study investigated the oxidizing capability of free radicals through the use of trapping agents. The results showed that hydroxyl radicals had the strongest oxidative capability, followed by superoxide anions and holes. These findings provide a solid scientific foundation for future research and development of efficient heterojunction compound catalysts. Full article

In this study, a colorimetric sensor was developed for the detection of organophosphorus pesticides (OPs) using a heterogeneous nanozyme with phosphatase-like activity. Herein, this heterogeneous nanozyme (Au-pCeO₂) was obtained by the modification of gold nanoparticles on porous cerium oxide nanorods, resulting in synergistic hydrolysis performance for OPs. Taking methyl parathion (MP) as the target pesticide, the catalytic performance and mechanism of Au-pCeO₂ were investigated. Based on the phosphatase-like Au-pCeO₂, a dual-mode colorimetric sensor for MP was put forward by the analysis of the hydrolysis product via a UV-visible spectrophotometer and a smartphone. Under optimum conditions, this dual-mode strategy can be used for the on-site analysis of MP with concentrations of 5 to 200 μM. Additionally, it can be applied for MP detection in pear and lettuce samples with recoveries ranging from 85.27% to 115.87% and relative standard deviations (RSDs) not exceeding 6.20%, which can provide a simple and convenient method for OP detection in agricultural products. Full article

The use of pesticides in agricultural practices raises concerns considering the toxic effects they generate in the environment; thus, their sustainable application in crop production remains a challenge. One of the frequently addressed issues regarding their application includes the development of a sustainable and ecofriendly approach for their degradation. Since the filamentous fungi can bioremediate various xenobiotics owing to their efficient and versatile enzymatic machinery, this review has addressed their performance in the biodegradation of organochlorine and organophosphorus pesticides. It is focused particularly on fungal strains belonging to the genera Aspergillus and Penicillium, since both are ubiquitous in the environment, and often abundant in soils contaminated with xenobiotics. Most of the recent reviews on microbial biodegradation of pesticides focus primarily on bacteria, and the soil filamentous fungi are mentioned only marginally there. Therefore, in this review, we have attempted to demonstrate and highlight the exceptional potential of aspergilli and penicillia in degrading the organochlorine and organophosphorus pesticides (e.g., endosulfan, lindane, chlorpyrifos, and methyl parathion). These biologically active xenobiotics have been degraded by fungi into various metabolites efficaciously, or these are completely mineralized within a few days. Since they have demonstrated high rates of degradation activity, as well as high tolerance to pesticides, most of the Aspergillus and Penicillium species strains listed in this review are excellent candidates for the remediation of pesticide-contaminated soils. Full article

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. Full article

The effects of the presence of perfluorocarbons (PFC) with a gas transport function in media with different phototrophic microorganisms on their growth rates and the accumulation of their biomass when using free and immobilized cells as inoculums were investigated. The significant increase in the average rate of biomass accumulation as well as levels of biomass accumulation in the presence of various PFCs were established for Chlorella vulgaris cells. When 1 g/L glycerol was introduced into the growth medium with PFCs and C. vulgaris cells, the increase in the rate of biomass accumulation was 9–32%. The maximum intracellular ATP concentrations corresponded to the combination of microalgae (Chlorella vulgaris) with bacterial cells (Pseudomonas esterophilus and Rhodoccus ruber) obtained with a mass ratio of 25:1. It provided for the formation of a consortium, which was able to accumulate the maximum amount of microalgae biomass for 3 days in the medium with PFCs and organophosphorus pesticide. The obtained data allow, on the one hand, predicting the growth of microalgae under environmental conditions in media with PFC pollution and, on the other hand, developing approaches to regulation of phototrophic microorganisms’ growth in order to obtain and use their high biomass yields for various purposes. Full article

Methyl parathion (MP) has been widely used as an organophosphorus pesticide for food preservation and pest management, resulting in its accumulation in the aquatic environment. However, the early developmental toxicity of MP to non-target species, especially aquatic vertebrates, has not been thoroughly investigated. In this study, zebrafish embryos were treated with 2.5, 5, or 10 mg/L of MP solution until 72 h post-fertilization (hpf). The results showed that MP exposure reduced spontaneous movement, hatching, and survival rates of zebrafish embryos and induced developmental abnormalities such as shortened body length, yolk edema, and spinal curvature. Notably, MP was found to induce cardiac abnormalities, including pericardial edema and decreased heart rate. Exposure to MP resulted in the accumulation of reactive oxygen species (ROS), decreased superoxide dismutase (SOD) activity, increased catalase (CAT) activity, elevated malondialdehyde (MDA) levels, and caused cardiac apoptosis in zebrafish embryos. Moreover, MP affected the transcription of cardiac development-related genes (vmhc, sox9b, nppa, tnnt2, bmp2b, bmp4) and apoptosis-related genes (p53, bax, bcl2). Astaxanthin could rescue MP-induced heart development defects by down-regulating oxidative stress. These findings suggest that MP induces cardiac developmental toxicity and provides additional evidence of MP toxicity to aquatic organisms. Full article

In this study, nanostructured gold was successfully prepared on a bare Au electrode using the electrochemical deposition method. Nanostructured gold provided more exposed active sites to facilitate the ion and electron transfer during the electrocatalytic reaction of organophosphorus pesticide (methyl parathion). The morphological and structural characterization of nanostructured gold was conducted using field-emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD), which was further carried out to evaluate the electrocatalytic activity towards methyl parathion sensing. The electrochemical performance of nanostructured gold was investigated by electrochemical measurements (cyclic voltammetry (CV) and differential pulse voltammetry (DPV)). The proposed nanostructured gold-modified electrode exhibited prominent electrochemical methyl parathion sensing performance (including two linear concentration ranges from 0.01 to 0.5 ppm (R² = 0.993) and from 0.5 to 4 ppm (R² = 0.996), limit of detection of 5.9 ppb, excellent selectivity and stability), and excellent capability in determination of pesticide residue in real fruit and vegetable samples (bok choy and strawberry). The study demonstrated that the presented approach to fabricate a nanostructured gold-modified electrode could be practically applied to detect pesticide residue in agricultural products via integrating the electrochemical and gas chromatography coupled with mass spectrometry (GC/MS-MS) analysis. Full article