Green synthesis of Ag and Pd nanoparticles for water pollutants treatment

Bio fabricated palladium nano particles using phytochemicals from aqueous cranberry fruit extract for anti-bacterial, cytotoxic activities and photocatalytic degradation of anionic dyes

The low cost and ecological compatibility of green technology makes it superior to chemical approaches in the generation of metal nanoparticles. The current study shows the use of cranberry fruit extract in the environmentally friendly green production of palladium nanoparticles. It is well known that the fruit extract from cranberries has a rich phytochemical composition that makes it a useful bio reducing agent for the formation of PdNPs. Several spectroscopic techniques, including ultraviolet-visible spectroscopy (UV-vis), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDX), were used to characterize the palladium nanoparticles (PdNPs). The diffractogram of the XRD analysis shows significant reflections at 39.98° (111), 46.49° (200), and 67.95° (220), which indicate the face-centered cubic (FCC) structure of PdNPs and demonstrate the crystallinity of the produced nanoparticles from the green method. The SEM and TEM structural and morphological analyses reveal that the synthesized nanoparticles have a spherical shape with size ranging between 2 nm to 50 nm. In addition, the synthesized PdNPs demonstrated possible antibacterial activity on both Gram-positive and Gram-negative bacteria as well as a cytotoxic effect on the MCF-7 breast cancer cell line. The degradation of Indigo Carmine (IC) and Sunset Yellow (SY) dyes can be effectively catalyzed by biogenic PdNPs, according to the results.

Inhibition performance of almond shell hydrochar-based fish oil emulsion gel on Klebsiella pneumonia inoculated fish skin and its characteristics

In this study, the inhibition potential against Klebsiella pneumoniae (K. pneumoniae) and the characterization of fish oil (FO) emulsion gel (EGE) containing almond shell hydrochar (AH) were investigated. Oily water of mullet liver was emulsified using tween 80, then gelled using gelatin and finally immobilized into hydrochar using an ultrasonic homogenizer. Characteristics and surface analysis of hydrochar-based emulsion gel (HEGE) were examined using FTIR and SEM. Stability, particle size distribution and zeta potential of HEGE were measured. In this study, a zeta potential of -18.46 indicated that HEGE was more stable than EGE (35.7 mV). The addition of hydrochar to the emulsion gel containing micro-droplets enabled the structure to become fully layered and stable. Time-dependent inactivation of K. pneumoniae exposed to HEGE and fixed in 6 mm-fish skin was evaluated for the first time in this study. While the highest log reduction and percent reduction in the bacterial count were achieved within 5 min with 0.87 CFU/cm2 and 86.60% with EGE, the lowest log reduction and percent reduction were achieved with 0.003 CFU/cm2 and 0.082% with HEGE in 30 min. In conclusion, the almond shell hydrochar-immobilized emulsion gel is a functional adsorbent that can inhibit K. pneumonia, and its stability and performance make it a unique candidate for further studies in this field.

Silver-based gels for oral and skin infections: antimicrobial effect and physicochemical stability

Aim: To systematically evaluate the literature on silver (Ag) gels and their antimicrobial efficacy and physicochemical stability. Materials & methods: A search was performed in PubMed/MEDLINE, LILACS, Web of Science, Scopus, Embase and Google Scholar. Results: Gels were formulated with Ag nanoparticles, Ag oxynitrate and colloidal Ag and showed antimicrobial activity for concentrations ranging from 0.002 to 30%. Gels showed stability of their chemical components, and their physicochemical properties, including viscosity, organoleptic characteristics, homogeneity, pH and spreadability, were suitable for topical application. Conclusion: Ag-based gels show antimicrobial action proportional to concentration, with higher action against Gram-negative bacteria and physicochemical stability for oral and skin infection applications.

Recent insights into metallic nanoparticles in shelf-life extension of agrifoods: Properties, green synthesis, and major applications

Nanotechnology emerged as a revolutionary technology in various fields of applied sciences, such as biomedical engineering and food technology. The pivotal roles of nanocompounds have been explored in various fields, such as food protection, preservation, and enhancement of shelf life. In this sequence, metallic nanoparticles (MNPs) are proven to be useful in developing products with antimicrobial activity and subsequently improve the shelf life of agrifoods. The major application of MNPs has been observed in the packaging industry due to the combining ability of biopolymers with MNPs. In recent years, various metal nanoparticles have been explored to formulate various active food packaging materials. However, the method of production and the need for risk evaluation are still a topic of discussion among researchers around the world. In general, MNPs are synthesized by various chemical and physical means, which may pose variable health risks. To overcome such issues, the green synthesis of MNPs using microbial and plant extracts has been proposed by various researchers. In this review, we aimed at exploring the green synthesis of MNPs, their properties and characterization, various ways of utilizing MNPs to extend their shelf life, and, most importantly, the risk associated with these along with their quality and safety considerations.

Green Synthesis of Pd Nanoparticles for Sustainable and Environmentally Benign Processes

Among transition metal nanoparticles, palladium nanoparticles (PdNPs) are recognized for their high catalytic activity in a wide range of organic transformations that are of academic and industrial importance. The increased interest in environmental issues has led to the development of various green approaches for the preparation of efficient, low-cost and environmentally sustainable Pd-nanocatalysts. Environmentally friendly solvents, non-toxic reducing reagents, biodegradable capping and stabilizing agents and energy-efficient synthetic methods are the main aspects that have been taken into account for the production of Pd nanoparticles in a green approach. This review provides an overview of the fundamental approaches used for the green synthesis of PdNPs and their catalytic application in sustainable processes as cross-coupling reactions and reductions with particular attention afforded to the recovery and reuse of the palladium nanocatalyst, from 2015 to the present.

Green Synthesis of Metallic Nanoparticles: Applications and Limitations

The past decade has witnessed a phenomenal rise in nanotechnology research due to its broad range of applications in diverse fields including food safety, transportation, sustainable energy, environmental science, catalysis, and medicine. The distinctive properties of nanomaterials (nano-sized particles in the range of 1 to 100 nm) make them uniquely suitable for such wide range of functions. The nanoparticles when manufactured using green synthesis methods are especially desirable being devoid of harsh operating conditions (high temperature and pressure), hazardous chemicals, or addition of external stabilizing or capping agents. Numerous plants and microorganisms are being experimented upon for an eco–friendly, cost–effective, and biologically safe process optimization. This review provides a comprehensive overview on the green synthesis of metallic NPs using plants and microorganisms, factors affecting the synthesis, and characterization of synthesized NPs. The potential applications of metal NPs in various sectors have also been highlighted along with the major challenges involved with respect to toxicity and translational research.