Green synthesis of bimetallic PdcoreAushell nanoparticles for enhanced solid-phase photodegradation of low-density polyethylene film

Bio-formulated chitosan nanoparticles enhance disease resistance against rice blast by physiomorphic, transcriptional, and microbiome modulation of rice (Oryza sativa L.)

Rice blast disease (RBD) caused by Magnaporthe oryzae, threaten food security by cutting agricultural output. Nano agrochemicals are now perceived as sustainable, cost-effective alternatives to traditional pesticides. This study investigated bioformulation of moringa chitosan nanoparticles (M-CsNPs) and their mechanisms for suppressing RBD while minimizing toxic effects on the microenvironment. M-CsNPs, sized 46 nm with semi-spherical morphology, significantly suppressed pathogen growth, integrity, and colonization at 200 mg L-1in vitro. Greenhouse tests with foliar exposure to the same concentration resulted in a substantial 77.7 % reduction in RBD, enhancing antioxidant enzyme activity and plant health. Furthermore, M-CsNPs improved photosynthesis, gas exchange, and the nutritional profile of diseased rice plants. RNA-seq analysis highlighted upregulated defense-related genes in treated rice plants. Metagenomic study showcased reshaping of the rice microbiome, reducing Magnaporthe abundance by 93.5 %. Both healthy and diseased rice plants showed increased microbial diversity, particularly favoring specific beneficial species Thiobacillus, Nitrospira, Nocardioides, and Sphingomicrobium in the rhizosphere and Azonexus, Agarivorans, and Bradyrhizobium in the phyllosphere. This comprehensive study unravels the diverse mechanisms by which M-CsNPs interact with plants and pathogens, curbing M. oryzae damage, promoting plant growth, and modulating the rice microbiome. It underscores the significant potential for effective plant disease management.

Theranostic aspects of palladium-based bimetallic nanoparticles in biomedical field: A state-of-the-art

The exploration of newer antibacterial strategies is driven by antibiotic-resistant microbes that cause serious public health issues. In recent years, nanoscale materials have developed as an alternative method to fight infections. Despite the fact that many nanomaterials have been discovered to be harmful, numerous researchers have shown a keen interest in nanoparticles (NPs) made of noble metals like silver, gold and platinum. To make environmentally safe NPs from plants, green chemistry and nanotechnology have been combined to address the issue of toxicity. The study of bimetallic nanoparticles (BNPs) has increased tremendously in the past 10 years. The production of BNPs mediated by natural extracts is straightforward, low cost and environmentally friendly. Due to their low toxicity, safety and biological stability, noble BNPs with silver, gold, platinum and palladium have the potential to be used in biomedical applications. They have a significant impact on human health and are used in medicine and pharmacy due to their biological characteristics, which include catalytic, antioxidant, antibacterial, antidiabetic, anticancer, hepatoprotective and regenerative activity.

Photocatalytic solid-phase degradation of polyethylene with fluoride-doped titania under low consumption ultraviolet radiation

Photodegradation of plastic in solid-phase requires the polymer to be composited with an efficient photocatalyst. We report herein the successful synthesis and characterization of fluoride-doped-TiO₂ and its applicability, for the first time, on solid-phase photodegradation of polyethylene films. Nearly half weight loss of polyethylene, containing only 2% of the photocatalyst, is eliminated after three weeks of ultraviolet A radiation using a low consumption light emitting diode lamp, defeating previously reported data. The half-life time of the plastic was around 3 weeks, highlighting the viability of this process for real applications. Results were compared to raw PE and PE composite with well-known TiO₂, resulting in, respectively, 0 and 26% of weight loss. The degradation process was monitored by optical microscopy, scanning electron microscopy, X-ray diffraction, thermogravimetric analysis, Fourier transform infrared and X-ray photoelectron spectroscopy, which revealed the formation of plastic cracks, loss of polyethylene crystallinity and thus stability, the oxidation of C-H bonds and the oxidized state of the surface compounds during photodegradation. The obtained results open a path for the future production of cleaner and self-photodegradable plastics, where the photocatalyst would be introduced in all the manufactured plastics, making possible the quicker photodegradation of the plastics that end up on the environment and the plastics reaching wastewater treatment plants.

Green synthesis of chitosan nanoparticles, optimization, characterization and antibacterial efficacy against multi drug resistant biofilm-forming Acinetobacter baumannii

Chitosan nanoparticles (CNPs) are promising versatile cationic polymeric nanoparticles, which have received growing interest over last few decades. The biocompatibility, biodegradability, environmental safety and non-toxicity of the chitosan nanoparticles makes it preferred for a wide range of biological applications including agriculture, medical and pharmaceutical fields. In this study, CNPs were biosynthesized by aqueous extract of Eucalyptus globulus Labill fresh leaves as bio-reductant. Box-Behnken design in 29 experimental runs was used for optimization of different factors affecting the production of CNPs. The maximum yield of CNPs was 9.91 mg/mL at pH of 4.5, chitosan concentration of 1%, incubation time of 60 min and temperature of 50 °C. The crystallinity, particle size and morphology of the biosynthesized CNPs were characterized. The CNPs possess a positively charged surface of 31.1 mV. The SEM images of the CNPs confirms the formation of spherical form with smooth surface. The TEM images show CNPs were spherical in shape and their size range was between 6.92 and 10.10 nm. X-ray diffraction indicates the high degree of CNPs crystallinity. FTIR analysis revealed various functional groups of organic compounds including NH, NH2, C-H, C-O, C-N, O-H, C-C, C-OH and C-O-C. The thermogravimetric analysis results revealed that CNPs are thermally stable. The antibacterial activity of CNPs was determined against pathogenic multidrug-resistant bacteria, Acinetobacter baumannii. The diameters of the inhibition zones were 12, 16 and 30 mm using the concentrations of 12.5, 25 and 50 mg/mL; respectively. When compared to previous studies, the biosynthesized CNPs produced using an aqueous extract of fresh Eucalyptus globulus Labill leaves have the smallest particle sizes (with a size range between 6.92 and 10.10 nm). Consequently, it is a promising candidate for a diverse range of medical applications and pharmaceutical industries.

A Survey on Analytical Methods for the Characterization of Green Synthesized Nanomaterials

Nowadays, nanotechnologies are well established and the uses of a great variety of nanomaterials show exponential growth. The development of green synthesis procedures experienced a great development thanks to the contribution of researchers of diverse origins. The versatility of green chemistry allows producing a wide range of organic and inorganic nanomaterials with numerous promising applications. In all cases, it is of paramount importance to carefully characterize the resulting nanomaterials because their properties will determine their correct performance to accomplish the function to which they were synthesized or even their detrimental effects like nanotoxicological behavior. This review provides an overview of frequently employed characterization methods and their applications for green synthesized nanomaterials. However, while several different nanoscale materials and their associated green construction methodology are being developed, other important techniques would be extensively incorporated into this field soon. The aim is to encourage researchers in the field to employ a variety of these techniques for achieving an exhaustive characterization of new nanomaterials and for contributing to the development of validated green synthesis procedures.

Biogenic synthesis of bimetallic nanoparticles and their applications

The current advancements in nanotechnology suggest a sustainable development in the green synthesis of bimetallic nanoparticles (BMNPs) through green approaches. Though challenging, nano phyto technology has versatile methods to achieve desired unique properties like optic, electronic, magnetic, therapeutic, and catalytic efficiencies. Bio-inspired, facile synthesis of bifunctional BMNPs is possible using abundant, readily available natural plant sources, bio-mass wastes and microorganisms. Synergistic effects of two different metals on mixing, bring new insight for the vast applications, which is not achievable in using monometallic NPs. By adopting bio-inspired greener approaches for synthesizing NPs, the risk of environmental toxicity caused by conventional physicochemical methods become negligible. This article hopes to provide the significance of cost-effective, one-step, eco-friendly and facile synthesis of noble/transition bimetallic NPs. This review article endows an overview of the bio-mediated synthesis of bimetallic NPs, classifications of BMNPs, current characterization techniques, possible mechanistic aspects for reducing metal ions, and the stability of formed NPs and bio-medical/industrial applications of fabricated NPs. The review also highlights the prospective future direction to improve reliability, reproducibility of biosynthesis methods, its actual mechanism in research works and extensive application of biogenic bimetallic NPs.