Silver nano-particles: synthesis and characterization by using glucans extracted from Pleurotus ostreatus

Integrated deep eutectic system enrichment and AI-assisted high-throughput visual detection for Hg2+ in environmental samples

INTRODUCTION

Mercury ion (Hg2+), a prevalent heavy metal, is commonly found in environmental soils and waters. Its interaction with sulfhydryl groups in proteins and lipids can cause oxidative stress and disruption of calcium homeostasis. These lead to severe health issues, including digestive, nervous, and immune system damage. Conventional Hg2+ detection methods, such as ICP-MS and AAS, require complex procedures and bulky instruments, limiting their applicability for real-time, on-site analysis. Recently, AI-assisted detection methods have emerged as promising solutions, offering portability and rapid detection capabilities. Deep eutectic solvents (DESs), and in particularly hydrophobic DESs (HDESs), provide an environmentally friendly alternative for the enrichment and detection metal ions.

OBJECTIVES

This study aims to develop a portable, cost-effective, and environmentally friendly colorimetric sensing platform based on a silver nanoparticles hydrophobic deep eutectic system (AgNPs-HDES) for Hg2+ enrichment and detection.

METHODS

AgNPs-HDES was synthesized using silver nanoparticle-containing ethylene glycol (AgNPs-EG) as the hydrogen bond donor. Electrostatic potential maps (ESP) and density functional theory (DFT) were employed to elucidate its synthesis and enrichment mechanisms. Smartphone-based image acquisition combined with YOLOv8-based AI software enabled high-throughput colorimetric analysis for Hg2+ detection.

RESULTS

A progressive color change from brownish-yellow to colorless was observed with increasing Hg2+ concentration, thereby eliminating hydrophilic interference and improving sensitivity. The AgNPs-HDES platform demonstrated a linear detection range of 1-40 μmol·L-1 (R2 = 0.9889) and a detection limit of 0.23 μmol·L-1. Recovery rates in real samples, including lake water, soil, seawater and industrial sewage, ranged from 90.3% to 123%.

CONCLUSION

The established platform enables portable, rapid, and highly accurate Hg2+ detection across multiple environmental samples simultaneously. This AI-assisted, high-throughput detection system presents a valuable tool for environmental monitoring and pollutant tracking.

Determination of antibacterial and antioxidant potential of organic crude extracts from Malus domestica, Cinnamomum verum and Trachyspermum ammi

Plants are the rich source of biologically active compounds which can be obliging against various pathogenic microorganisms and cancerous diseases. The current study evaluated the antibacterial potential of aqueous, methanol, ethanol, and acetone extracts of Malus domestica (apple), Cinnamomum verum (cinnamon) and Trachyspermum ammi (ajwain) via agar well diffusion methods and minimum inhibitory concentration (MIC) in (mm) against Staphylococcus aureus (ATCC 25923) and Salmonella typhi (ATCC 19430). The antioxidant properties including total phenolic content (TPC), total flavonoid content (TFC), DPPH and reducing power was determined by UV/VIS spectrophotometery and all the results interpreted through one way ANOVA (STATISTICA). In the results, methanolic and acetonic extracts of C. verum has shown maximum zone of inhibition (22.3 ± 0.58 mm) against S. aureus while for C. verum and T. ammi, ethanolic extracts has expressed the maximum zone of inhibition (22.3 ± 0.58 mm) against S. typhi and for M. domestica the methanolic extracts has exhibited highest zone of inhibition (18 ± 0.56 mm) among all other extracts of M. domestica. The MIC values were comparable with antimicrobial activity. Among the antioxidant activity analysis, the highest level of TPC has observed in aqueous extract of M. domestica 72.15 ± 1.80 mg GAE/g, while highest TFC was observed in methanolic extracts of M. domestica 15.62 ± 0.25 µg CE/g. The DPPH assay showed maximum percentage inhibition 123% in the methanolic extract of M. domestica, while highest reducing potential 13.42 ± 1.15 nm was observed in aqueous extract of C. verum. This study has compared three potential medicinal plants with biological active and eco-friendly components which play crucial role in therapeutics.

Nature-Inspired Antimicrobial Agents: Cinnamon-Derived Copper Oxide Nanoparticles for Effective Aspergillus Niger Control

The emergence of resistant bacterial and fungal strains poses significant challenges in various industrial processes including food, medicines, and leather industry. It necessitates the development of novel and effective antimicrobial agents. In the present work, we have developed an ecofriendly and sustainable approach to synthesize silver-doped copper oxide nanoparticles by using cinnamon bark extract (C-CuO/Ag). The nanoparticles were characterized via UV-visible spectroscopy at 190-800 nm, FT-IR, SEM-EDAX, XRD, and further subjected to determine antimicrobial potential, minimum inhibitory concentration (MIC), and anti-biofilm potential against both bacterial and fungal species. UV-visible spectrum showed maximum absorption at 210 nm in ultraviolet range and 419 nm in visible range. Various strong and weak peaks were obtained in FT-IR spectra, which defined the presence of corresponding functional groups in C-CuO/Ag nanoparticles. SEM analysis revealed the tightly packed confirmation, while EDS confirmed the elemental analysis of C-CuO/Ag nanoparticles. XRD spectrum of C-CuO/Ag nanoparticles showed strong diffraction peaks at 2Ө of 31.92˚, 35.67˚, and 48.51˚, which confined with the plane indices of (-110), (111), and (- 202), respectively, while weak diffraction peaks at 2Ө of 56.31˚, 58.9˚, and 77.4˚, which leads to the crystal planes of (202), (- 220), and (311), respectively. Antimicrobial assays showed clear zones of inhibition against microbial strains as maximum inhibition diameter was observed against Aspergillus niger (31.5 ± 0.7 mm) followed by Escherichia coli (30.1 ± 0.3 mm) and Staphylococcus aureus (29.5 ± 0.7 mm). These findings provide support clear evidence that CuO nanoparticles can serve as potent antibacterial and antifungal compounds against highly resistive and pathogenic microbial strains.

Bioengineering of glucan coated silver nanoparticles as dynamic biomedical compound; in vitro and in vivo studies

The use of silver nanoparticles (AgNPs) gaining importance for the treatment of microbial infections and are in great demand due to their efficient broad antibacterial action but there is only one problem that silver nanoparticles can cause tissue damage. Therefore, the present study evaluated antimicrobial potential and intricacy of glucan coated silver nanoparticles in comparison with free silver nanoparticles. In this study, glucan coated silver nanoparticles (Glucan-AgNPs) by using Pleurotus spps. were characterized for their antimicrobial, minimum inhibitory concentration (MIC), biofilm inhibition, mutagenicity potential, hemolytic activities and histological examination through in vitro and in vivo analysis. The liver, kidney, intestine, and skin tissues were examined to gauge the adverse effects of the treatment method's toxicity by silver deposition. The results of this study have shown that mushroom's glucan extracted from Pleurotus spps. are excellent reducing agent and due to their best capping ability they reduce the toxicity of AgNPs and enhance their antimicrobial activities. The highest zone of inhibition was observed by Glucan-AgNPs from P. ostreatus (24 mm) against S. aureus while least zone of inhibition was resulted from Glucan-AgNPs from P. sapidus (14 mm) against B. subtilis. The results for biofilm inhibition showed excellent biofilm inhibition ability of Glucan-AgNPs. In results, maximum inhibition 95.2 % was observed by Glucan-AgNPs from P. ostreatus against S. aureus, while minimum inhibition 79.2 % by Glucan-AgNPs of P. sapidus against E. coli. Furthermore, Glucan-AgNPs treated mice showed no deposition and damage in the organs. Glucan-AgNPs has a higher efficacy in treating microbial infection.

Highly Selective Colorimetric Sensor of Mercury(II) Ions by Andrographolide-Stabilized Silver Nanoparticles in Water and Antibacterial Evaluation

Silver nanoparticles (AgNPs) are well known for their exceptional properties and versatility in various applications. This study used andrographolide as a biochemical stabilizer to synthesize AgNPs (andro-AgNPs). The andro-AgNPs were characterized by using UV-vis spectroscopy, revealing a surface plasmon resonance peak at 440 nm. Fourier transform infrared spectroscopy was also used to confirm the presence of AgNPs. Transmission electron microscopy was used to investigate the morphology of andro-AgNPs, which showed a spherical shape with an average diameter of 18.30 ± 5.57 nm (n = 205). Andro-AgNPs were utilized as a colorimetric sensor to detect mercury ions (Hg2+) in water, and the optimized detection conditions were evaluated using UV-vis spectroscopy with a linear range of 15-120 μM. The limit of detection and the limit of quantification for Hg2+ detection were found to be 11.15 and 37.15 μM, respectively. Furthermore, andro-AgNPs exhibited antibacterial properties against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. The results imply that andro-AgNPs hold promising potential for future biomedical applications.

Iron Oxide Nanoparticle Biosynthesis, Characterization, and Antimicrobial Activity Using Nigella sativa Seeds Extract

In the most recent few years, there has been a significant uptick in curiosity regarding the process of manufacturing metal oxide nanoparticles by making use of the extract of various plant components. The generated iron oxide nanoparticles demonstrate validity for use in biomedical applications. In the work that we are presenting here, we use the extract of Nigella sativa seeds to carry out an environmentally friendly iron oxide nanoparticle synthesis (Fe2O3 NPs). Advanced diagnostic tools such as scanning electron microscopy (SEM), Fourier transform infrared (FTIR) analysis, X-ray diffraction (XRD) investigation, and others were utilized in order to perform structural characterization on the generated Fe2O3 NPs. According to the preliminary findings, the particles have a semispherical form with an average particle size that falls between 15[Formula: see text]nm and 20[Formula: see text]nm. Phytochemicals, particularly polyphenols, are extremely important contributors to the production of iron oxide nanoparticles. Since the findings of the antimicrobial investigation were highly encouraging, the antimicrobial activity of the iron oxide particles that were created was investigated to see if they might inhibit the growth of specific bacterial and fungal pathogens.

Phytobioactive compounds as therapeutic agents for human diseases: A review

Phytobioactive compounds are plant secondary metabolites and bioactive compounds abundantly present in medicinal plants and have remarkable therapeutic potential. Oxidative stress and antibiotic resistance are major causes of present-day ailments such as diabetes, atherosclerosis, cardiovascular disorders, cancer, and inflammation. The data for this review were collected from Google Scholar, PubMed, Directory of Open Access Journals (DOAJ), and Science Direct by using keywords: "Medicinal plants, Phytobioactive compounds, Polyphenols, Alkaloids, Carotenoids etc." Several studies have reported the pharmacological and therapeutic potential of the phytobioactives. Polyphenols, alkaloids, terpenes, and polysaccharides isolated from medicinal plants showed remarkable antioxidant, anticancer, cytotoxic, anti-inflammatory, cardioprotective, hepatoprotective, immunomodulatory, neuroprotective, and antidiabetic activities. This literature review was planned to provide comprehensive insight into the biopharmacological and therapeutic potential of phytobioactive compounds. The techniques used for the extraction and isolation of phytobioactive compounds, and bioassays required for their biological activities such as antioxidant, antimicrobial, anti-inflammatory, and cytotoxic activities, have been discussed. Characterization techniques for the structural elucidation of phytobioactive compounds such as HPLC, TLC, FTIR, GC-MS/MS, and NMR have also been discussed. This review concludes that phytobioactive compounds may be used as potential alternative to synthetic compounds as therapeutic agents for the treatment of various diseases.

β-Glucan-Functionalized Nanoparticles Down-Modulate the Proinflammatory Response of Mononuclear Phagocytes Challenged with Candida albicans

Systemic fungal infections are associated with significant morbidity and mortality, and Candida albicans is the most common causative agent. Recognition of yeast cells by immune cell surface receptors can trigger phagocytosis of fungal pathogens and a pro-inflammatory response that may contribute to fungal elimination. Nevertheless, the elicited inflammatory response may be deleterious to the host by causing excessive tissue damage. We developed a nanoparticle-based approach to modulate the host deleterious inflammatory consequences of fungal infection by using β1,3-glucan-functionalized polystyrene (β-Glc-PS) nanoparticles. β-Glc-PS nanoparticles decreased the levels of the proinflammatory cytokines TNF-α, IL-6, IL-1β and IL-12p40 detected in in vitro culture supernatants of bone marrow-derived dendritic cells and macrophage challenged with C. albicans cells. Moreover, β-Glc-PS nanoparticles impaired the production of reactive oxygen species by bone marrow-derived dendritic cells incubated with C. albicans. This immunomodulatory effect was dependent on the nanoparticle size. Overall, β-Glc-PS nanoparticles reduced the proinflammatory response elicited by fungal cells in mononuclear phagocytes, setting the basis for a targeted therapy aimed at protecting the host by lowering the inflammatory cost of infection.

Green Synthesis of Nanoparticles by Mushrooms: A Crucial Dimension for Sustainable Soil Management

Soil is the main component in the agroecosystem besides water, microbial communities, and cultivated plants. Several problems face soil, including soil pollution, erosion, salinization, and degradation on a global level. Many approaches have been applied to overcome these issues, such as phyto-, bio-, and nanoremediation through different soil management tools. Mushrooms can play a vital role in the soil through bio-nanoremediation, especially under the biological synthesis of nanoparticles, which could be used in the bioremediation process. This review focuses on the green synthesis of nanoparticles using mushrooms and the potential of bio-nanoremediation for polluted soils. The distinguished roles of mushrooms of soil improvement are considered a crucial dimension for sustainable soil management, which may include controlling soil erosion, improving soil aggregates, increasing soil organic matter content, enhancing the bioavailability of soil nutrients, and resorting to damaged and/or polluted soils. The field of bio-nanoremediation using mushrooms still requires further investigation, particularly regarding the sustainable management of soils.

Green Biotechnology of Oyster Mushroom (Pleurotus ostreatus L.): A Sustainable Strategy for Myco-Remediation and Bio-Fermentation

The field of biotechnology presents us with a great chance to use many organisms, such as mushrooms, to find suitable solutions for issues that include the accumulation of agro-wastes in the environment. The green biotechnology of mushrooms (Pleurotus ostreatus L.) includes the myco-remediation of polluted soil and water as well as bio-fermentation. The circular economy approach could be effectively achieved by using oyster mushrooms (Pleurotus ostreatus L.), of which the substrate of their cultivation is considered as a vital source for producing biofertilizers, animal feeds, bioenergy, and bio-remediators. Spent mushroom substrate is also considered a crucial source for many applications, including the production of enzymes (e.g., manganese peroxidase, laccase, and lignin peroxidase) and bioethanol. The sustainable management of agro-industrial wastes (e.g., plant-based foods, animal-based foods, and non-food industries) could reduce, reuse and recycle using oyster mushrooms. This review aims to focus on the biotechnological applications of the oyster mushroom (P. ostreatus L.) concerning the field of the myco-remediation of pollutants and the bio-fermentation of agro-industrial wastes as a sustainable approach to environmental protection. This study can open new windows onto the green synthesis of metal-nanoparticles, such as nano-silver, nano-TiO2 and nano-ZnO. More investigations are needed concerning the new biotechnological approaches.