Search Results (6)

On a daily basis, a wide range of materials including inorganic nanoparticles (NPs) inadvertently find their way into the environment. Meanwhile, intentionally used NPs, such as the new generation of nanofertilizers (NFs) are designed to enhance agronomic production. However, their physicochemical properties and not-so-well understood effects raise potential risks to the plant reproductive cycle, specifically pollen development, a subject largely absent in academic research. Even slight contamination, deformation, or aberration of pollen could have enormous impacts on the ecosystem. Thus, our objective was to evaluate the influence of various metal-based NPs on sunflower pollen morphology and its yield. Nano-formulations were applied during the 2019–2021 agronomic seasons on two sunflower hybrids, Neostar and Edison, in Dolná Malanta, near Nitra, Slovak Republic. Pollen morphology findings indicated that conventional ZnSO₄ had the most positive impact on the size of pollen grains compared to ZnO-NPs, Fe₃O₄-NPs, and the NP-free control. Gold-NPs on SiO₂ mesoporous silica (AuSi-NPs) showed a statistically insignificant impact, while the use of TiO₂-NPs in agriculture remained a topic of debate. Surprisingly, pollen characteristics did not fully correspond to crop yields. Despite causing a reduction in pollen grain size, the TiO₂-NPs consistently showed the highest yield compared to other variants. Employing low concentrations of NFs did not notably alter pollen morphology, reinforcing our commitment to eco-friendly, precise, and sustainable agriculture. Full article

In environmental and agronomic settings, even minor imbalances can trigger a range of unpredicted responses. Despite the widespread use of metal-based nanoparticles (NPs) and new bio-nanofertilizers, their impact on crop production is absent in the literature. Therefore, our research is focused on the agronomic effect of spray application of gold nanoparticles anchored to SiO₂ mesoporous silica (AuSi-NPs), zinc oxide nanoparticles (ZnO-NPs), and iron oxide nanoparticles (Fe₃O₄-NPs) on sunflowers under real-world environments. Our findings revealed that the biosynthetically prepared AuSi-NPs and ZnO-NPs were highly effective in enhancing sunflower seasonal physiology, e.g., the value of the NDVI index increased from 0.012 to 0.025 after AuSi-NPs application. The distribution of leaf trichomes improved and the grain yield increased from 2.47 t ha⁻¹ to 3.29 t ha⁻¹ after ZnO-NPs application. AuSi-NPs treatment resulted in a higher content of essential linoleic acid (54.37%) when compared to the NPs-free control (51.57%), which had a higher determined oleic acid. No NPs or residual translocated metals were detected in the fully ripe sunflower seeds, except for slightly higher silica content after the AuSi-NPs treatment. Additionally, AuSi-NPs and NPs-free control showed wide insect biodiversity while ZnO-NPs treatment had the lowest value of phosphorus as anti-nutrient. Contradictory but insignificant effect on physiology, yield, and insect biodiversity was observed in Fe₃O₄-NPs treatment. Therefore, further studies are needed to fully understand the long-term environmental and agricultural sustainability of NPs applications. Full article

In this paper, a core-shell based on the Fe₃O₄@SiO₂@Au nanoparticle amplification technique for a surface plasmon resonance (SPR) sensor is proposed. Fe₃O₄@SiO₂@AuNPs were used not only to amplify SPR signals, but also to rapidly separate and enrich T-2 toxin via an external magnetic field. We detected T-2 toxin using the direct competition method in order to evaluate the amplification effect of Fe₃O₄@SiO₂@AuNPs. A T-2 toxin–protein conjugate (T2-OVA) immobilized on the surface of 3-mercaptopropionic acid-modified sensing film competed with T-2 toxin to combine with the T-2 toxin antibody–Fe₃O₄@SiO₂@AuNPs conjugates (mAb-Fe₃O₄@SiO₂@AuNPs) as signal amplification elements. With the decrease in T-2 toxin concentration, the SPR signal gradually increased. In other words, the SPR response was inversely proportional to T-2 toxin. The results showed that there was a good linear relationship in the range of 1 ng/mL~100 ng/mL, and the limit of detection was 0.57 ng/mL. This work also provides a new possibility to improve the sensitivity of SPR biosensors in the detection of small molecules and in disease diagnosis. Full article

There has been an increasing demand for rapid and sensitive techniques for the detection of heavy metal ions that are harmful to the human body in traditional Chinese medicine (TCM). However, the complex chemical composition of TCM makes the quantitative detection of heavy metal ions difficult. In this study, the magnetic Fe₃O₄@SiO₂@AuNPs nanoparticles combined with a probe molecule DMcT were used for the specific enrichment and detection of Hg²⁺ in the complex system of licorice. The core of Fe₃O₄ was bonded with SiO₂ to increase its stability. A layer of AuNPs was deposited to produce a “core–shell” Raman substrate with high surface-enhanced Raman spectroscopy (SERS) activity, which was surface modified by DMcT probe molecules with sulfhydryl groups. In the presence of Hg²⁺, Hg²⁺ binds to N on the amino group of DMcT to form N-Hg²⁺-N complexes, which induces Fe₃O₄@SiO₂@AuNPs-DMcT clustering to enhance SERS signal. The Raman probe molecule DMcT showed an excellent linear relationship (R² = 0.9709) between the SERS signal at 1416 cm⁻¹ and the Hg²⁺ concentration (0.5~100 ng/mL). This method achieved a good recovery (89.10~111.00%) for the practical application of detection of Hg²⁺ in licorice extracts. The results demonstrated that the functional Fe₃O₄@SiO₂@AuNPs-DMcT performed effective enrichment and showed high sensitivity and accurate detection of heavy metal ions from the analytes. Full article

A surface-enhanced Raman scattering (SERS) tag is proposed for high-sensitivity detection of gibberellin A₃ (GA₃). Silver nanoparticles (AgNPs) were synthesized using citrate reduction. 4-Mercaptobenzoic acid (MBA) was used for the Raman-labeled molecules, which were coupled to the surface of the AgNPs using sulfydryls. MBA was coated with silica using the Stöber method to prevent leakage. GA₃ antibodies were attached via the active functional groups N-Hydroxysuccinimide (NHS) and N-Ethyl-N’-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) to construct a novel immuno-AgNPs@SiO₂ SERS tags. The captured SERS substrates were fabricated through Fe₃O₄ nanoparticles and gold nanoparticles (AuNPs) using chemical methods. These nanoparticles were characterized using ultraviolet-visible spectroscopy (UV–Vis), dynamic light scattering, Raman spectroscopy, transmission electron microscope (TEM), and X-ray diffraction (XRD). This immuno-AgNPs@SiO₂ SERS tags has a strong SERS signal based on characterizations via Raman spectroscopy. Based on antigen-antibody reaction, the immuno-Au@Fe₃O₄ nanoparticles can capture the GA₃ and AgNPs@SiO₂ SERS tags. Due to the increasing number of captured nanoprobes, the SERS signal from MBA was greatly enhanced, which favored the sensitive detection of GA₃. The linear equation for the SERS signal was y = −13635x + 202211 (R² = 0.9867), and the limit of detection (LOD) was 10⁻¹⁰ M. The proposed SERS tags are also applicable for the detection of other food risk factors. Full article

Background and objectives: Although studies have elucidated the significant biomedical potential of biogenic metallic nanoparticles (MNPs), it is very important to explore the hazards associated with the use of biogenic MNPs. Evidence indicates that genetic toxicity causes mutation, carcinogenesis, and cell death. Materials and Methods: Therefore, we systematically review original studies that investigated the genotoxic effect of biologically synthesized MNPs via in vitro and in vivo models. Articles were systematically collected by screening the literature published online in the following databases; Cochrane, Web of Science, PubMed, Scopus, Science Direct, ProQuest, and EBSCO. Results: Most of the studies were carried out on the MCF-7 cancer cell line and phytosynthesis was the general approach to MNP preparation in all studies. Fungi were the second most predominant resource applied for MNP synthesis. A total of 80.57% of the studies synthesized biogenic MNPs with sizes below 50 nm. The genotoxicity of Ag, Au, ZnO, TiO₂, Se, Cu, Pt, Zn, Ag-Au, CdS, Fe₃O₄, Tb₂O₃, and Si-Ag NPs was evaluated. AgNPs, prepared in 68.79% of studies, and AuNPs, prepared in 12.76%, were the two most predominant biogenic MNPs synthesized and evaluated in the included articles. Conclusions: Although several studies reported the antigenotoxic influence of biogenic MNPs, most of them reported biogenic MNP genotoxicity at specific concentrations and with a dose or time dependence. To the best of our knowledge, this is the first study to systematically evaluate the genotoxicity of biologically synthesized MNPs and provide a valuable summary of genotoxicity data. In conclusion, our study implied that the genotoxicity of biologically synthesized MNPs varies case-by-case and highly dependent on the synthesis parameters, biological source, applied assay, etc. The gathered data are required for the translation of these nanoproducts from research laboratories to the clinical market. Full article