Aqueous electrophoretic deposition of citric-acid-stabilized copper nanoparticles

Soil and foliar exposure of soybean (Glycine max) to Cu: Nanoparticle coating-dependent plant responses

In this study, we investigated the effects of citric acid (CA) coated copper oxide nanoparticles (CuO NPs) and their application method (foliar or soil exposure) on the growth and physiology of soybean (Glycine max). After nanomaterials exposure via foliar or soil application, Cu concentration was elevated in the roots, leaves, stem, pod, and seeds; distribution varied by plant organ and surface coating. Foliar application of CuO NPs at 300 mg/L and CuO-CA NPs at 75 mg/L increased soybean yield by 169.5% and 170.1%, respectively. In contrast, foliar and soil exposure to ionic Cu with all treatments (75 and 300 mg/L) had no impact on yield. Additionally, CuO-CA NPs at 300 mg/L significantly decreased Cu concentration in seeds by 46.7%, compared to control, and by 44.7%, compared to equivalent concentration of CuO NPs. Based on the total Cu concentration, CuO NPs appeared to be more accessible for plant uptake, compared to CuO-CA NPs, inducing a decrease in protein content by 56.3% and inhibiting plant height by 27.9% at 300 mg/kg under soil exposure. The translocation of Cu from leaf to root and from the root to leaf through the xylem was imaged by two-photon microscopy. The findings indicate that citric acid coating reduced CuO NPs toxicity in soybean, demonstrating that surface modification may change the toxic properties of NPs. This research provides direct evidence for the positive effects of CuO-CA NPs on soybean, including accumulation and in planta transfer of the particles, and provides important information when assessing the risk and the benefits of NP use in food safety and security.

Copper nanoparticles induced, trimesic acid grafted cellulose-an effective, non-hazardous processing approach for multifunctional textile with low chemical induction

ABSTRACT

Cross-linkers have great importance in textile due to the widespread utilization of cellulosic fibers for clothing. Unfortunately, the acute toxicity of formaldehyde-based resins and the poor performance of non-formaldehyde resins still keep the research door open for scientists in this area. Herein, we demonstrated copper nanoparticles induced trimesic acid grafted cellulose as a sustainable solution for multifunctional easy-care clothing. Our treated fabric presents crease recovery angle value of 248° comparable to that of most promising citric acid-based cross-linkers at the chemical concentration of trimesic acid as low as 2% with a sweeping improvement of around 30% in strength retention, not reported earlier. The relatively low fabric stiffness, without any yellowing, is contributing to the comfort and aesthetic demand while nanoparticles induction promoting utmost antimicrobial need. For the first time, the superiority of the development was validated by interlacing the fabric/finish traits with sustainability building blocks that provide the step forward for rapid industrialization. Furthermore, environmental, health, and safety mapping comparison provides a better understanding of the intensity of hazards that different finishing crosslinkers pose on the environment and public health. With improved performance and superior sustainability, such fabric can act as a preferable alternative to the multifunctional easy-care fabric market.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s10570-021-04251-5.

Comparable antibacterial effects and action mechanisms of silver and iron oxide nanoparticles on Escherichia coli and Salmonella typhimurium

The current research reports the antibacterial effects of silver (Ag) and citric acid coated iron oxide (Fe₃O₄) NPs on Escherichia coli wild type and kanamycin-resistant strains, as well as on Salmonella typhimurium MDC1759. NPs demonstrated significant antibacterial activity against these bacteria, but antibacterial effect of Ag NPs is more pronounced at low concentrations. Ag NPs inhibited 60–90% of S. typhimurium and drug-resistant E. coli. The latter is more sensitive to Fe₃O₄ NPs than wild type strain: the number of bacterial colonies is decreased ~ 4-fold. To explain possible mechanisms of NPs action, H⁺-fluxes through the bacterial membrane and the H⁺-translocating F_OF₁-ATPase activity of bacterial membrane vesicles were studied. N,N′-Dicyclohexylcarbodiimide (DCCD)-sensitive ATPase activity was increased up to ~ 1.5-fold in the presence of Fe₃O₄ NPs. ATPase activity was not detected by Ag NPs even in the presence of DCCD, which confirms the bactericidal effect of these NPs. The H⁺-fluxes were changed by NPs and by addition of DCCD. H₂ yield was inhibited by NPs; the inhibition by Ag NPs is stronger than by Fe₃O₄ NPs. NPs showed antibacterial effect in bacteria studied in concentration-dependent manner by changing in membrane permeability and membrane-bound enzyme activity. The F_OF₁-ATPase is suggested might be a target for NPs.