Metal-based nanoparticles (NPs) (e.g., silver, zinc oxide, titanium dioxide, iron oxide) are being widely used in the nanotechnology industry. Because of the release of particles from NP-containing products, it is likely that NPs will enter the soil compartment, especially through land application of sewage sludge derived from wastewater treatment. This review presents an overview of the literature dealing with the fate and effects of metal-based NPs in soil. In the environment, the characteristics of NPs (e.g., size, shape, surface charge) and soil (e.g., pH, ionic strength, organic matter, and clay content) will affect physical and chemical processes, resulting in NP dissolution, agglomeration, and aggregation. The behavior of NPs in soil will control their mobility and their bioavailability to soil organisms. Consequently, exposure characterization in ecotoxicological studies should obtain as much information as possible about dissolution, agglomeration, and aggregation processes. Comparing existing studies is a challenging task, because no standards exist for toxicity tests with NPs. In many cases, the reporting of associated characterization data is sparse, or missing, making it impossible to interpret and explain observed differences in results among studies.

https://setac.onlinelibrary.wiley.com/doi/epdf/10.1002/etc.1880

Metal-based nanoparticles in soil: fate, behavior, and effects on soil invertebrates.

Nanomaterials, including metal-based nanoparticles, are used for various biological and medical applications. However, metals affect immune functions in many animal species including humans. Different physical and chemical properties induce different cellular responses, such as cellular uptake and intracellular biodistribution, leading to the different immune responses. The goals of this review are to summarize and discuss the innate and adaptive immune responses triggered by metal-based nanoparticles in a variety of immune system models.

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Metal-Based Nanoparticles and the Immune System: Activation, Inflammation, and Potential Applications

Biosynthesis of Ag nanoparticles (AgNPs) by Cacumen Platycladi extract was investigated. The AgNPs were characterized by ultraviolet–visible absorption spectroscopy (UV–vis), transmission electron microscopy (TEM), selected-area electron diffraction (SAED), and X-ray diffraction (XRD). The results showed that increasing the initial AgNO3 concentration at 30 or 60 °C increased the mean size and widened the size distribution of the AgNPs leading to red shift and broadening of the Surface Plasmon Resonance absorption. The conversion of silver ions was determined by atomic absorption spectroscopy (AAS) and to discuss the bioreductive mechanism, the reducing sugar, flavonoid, saccharide, protein contents in the extract, and the antioxidant activity were measured using 3,5-dinitrosalicylic acid colorimetric; Coomassie brilliant blue; phenol-sulfuric acid; rutin-based spectrophotometry method; and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging assay methods. The results showed that the reducing sug...

Biogenic Silver Nanoparticles by Cacumen Platycladi Extract: Synthesis, Formation Mechanism, and Antibacterial Activity

Antibacterial cotton fabric with enhanced durability prepared using silver nanoparticles and carboxymethyl chitosan

As nanotechnology is expanding to several commercial fields, there is a need of ecofriendly and energy-efficient methods for the synthesis of nanoparticles. Algae have been discovered to reduce metal ions and subsequently for the biosynthesis of nanoparticles. Since algae-mediated biosynthesis of nanoparticles is an ecofriendly, economical, high-yielding, expeditious and energy-efficient method, a large number of studies have been published in the last few years. This review article therefore is focused on recent progress on the utilization of algae of various classes, viz., Cyanophyceae, Chlorophyceae, Phaeophyceae, Rhodophyceae, etc. for the synthesis of nanoparticles, their characterization and the possible mechanisms involved.

Algae as crucial organisms in advancing nanotechnology: a systematic review

A novel nano-silver colloidal solution was prepared in one step by mixing AgNO3 aqueous solution and an amino-terminated hyperbranched polymer (HBP-NH2) aqueous solution under vigorous stirring at room temperature. All results of Dynamic Light Scattering (DLS), Transmission Electron Microscopy (TEM) and UV/Visible Absorption Spectrophotometry indicated that silver nanoparticles had been formed in colloidal solution. Cotton fabric was treated with nano-silver colloid by an impregnation method to provide the cotton fabric with antibacterial properties. The whiteness, silver content, antibacterial activity and washing durability of the silver-treated fabrics were determined. The results indicated that the silver-treated cotton fabric showed 99.01 % bacterial reduction of Staphylococcus aureus and 99.26 % bacterial reduction of Escherichia coli while the silver content on cotton was about 88 mg/kg. The antimicrobial activity of the silver-treated cotton fabric was maintained at over 98.77 % reduction level even after being exposed to 20 consecutive home laundering conditions. In addition, the results of scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) confirmed that silver nanoparticles have been fixed and well dispersed on cotton fabrics’ surface and the major state of the silver presented on the surface was Ag0.

/pdf/application-of-silver-nanoparticles-to-cotton-fabric-as-an-35am06xxka.pdf

Application of silver nanoparticles to cotton fabric as an antibacterial textile finish

The invention relates to an antibacterial treatment method for textiles, in particular to a finishing method for nano-silver antibacterial textiles, belonging to the textile after finishing technical field. The method comprises the following steps that: a textile is dipped in a nano-silver aqueous solution for 1-120 min, or a textile carrying amino-terminated overspending compound and quaternary ammonium salt thereof is dipped in a 0.01-0.5 mol/L silver nitrate solution for 1-120 min; after the textile is taken out, washed and air-dried, a nano-silver antibacterial textile is obtained; the nano-silver aqueous solution is obtained by mixing an amino-terminated overspending compound and quaternary ammonium salt aqueous solution having the mass percentage between 0.01 and 5 percent and a silver nitrate solution having the molality between 0.01 and 0.5 mol/L. The treatment method has the advantages of without needing additional dispersant, reductant or adhesive, simple process, convenient operation and excellently antibacterial performance of the obtained nano-silver antibacterial textile.

Nanometer silver antibiotic textile finishing method

The invention relates to a preparation method of nano-silver solution and belongs to the nanophase material field. The technical scheme is as following: the amino end group overspending compound water solution with the mass percentage of 0.01 percent to 5 percent is mixed with the silver nitrate solution with the mass molality of 0.01 to 0.5 mol/L, the mixture is stirred for 1 to 120 minutes at the temperature of 10 to 100 DEG C to obtain the nano-silver solution with the particle diameter of 1 to 100nm. The method has the advantages of simple technique and high efficiency, the nano-silver solution obtained by the method has the advantages of little impurity, high stability, small particle diameter and uniform dispersion, which can be widely used in the fields of electronic products, spinning, health and medical, food, painting and plastics, etc.

Method of preparing nano-silver water solution

Fiber-Optic Microfiber: Tracking Activity Enhancement and Suppression of Heterogeneous Photocatalysts

The use of light, which is s a powerful tool for imaging and sensing, has also become one of the most prospective strategies in tumor treatment. Optical microfibers, which have engineerable waveguiding properties, are highly attractive for optical sensing and photothermal therapy on the micro/nanoscale. However, for their real‐world application, the sensitivity limit needs to be addressed, as does the issue of improving the intrinsic photothermal performance of silica microfibers. Herein, a nanointerface consisting of triangular Au@Ag2S nanoplates and VO2 nanoparticles on an optical microfiber is designed to fabricate a structurally resilient hierarchical microfiber sensor with well‐distributed plasmonic hotspot enhancement. The nanointerface enhances the evanescent field with temperature tunability, adding a self‐photothermal modulation function to the sensor. The sensor exhibits a temperature‐tunable sensitivity to alpha‐fetoprotein with a limit of detection of 0.62 × 10−18 m. It differentiates hepatoma carcinoma cells from normal cells and provides photothermal therapy aimed at the former. Quantitative evaluation of the sensor indicates that photothermal therapy kills more than 82% of cancer cells using a lower power. This work provides a new opportunity for selective evanescent field modulation for evanescent biosensors as well as a potential approach to the integration of cellular diagnosis and therapy.

Xiaolan Wu

Papers

Application of silver nanoparticles to cotton fabric as an antibacterial textile finish

Nanometer silver antibiotic textile finishing method

Method of preparing nano-silver water solution

Fiber-Optic Microfiber: Tracking Activity Enhancement and Suppression of Heterogeneous Photocatalysts

Ultrasensitive Detection and Cellular Photothermal Therapy via a Self‐Photothermal Modulation Biosensor