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In this study, a colorimetric discrimination of Pd2+ and Hg2+ ions in the solvent and solid film states in a silver nanoparticle (AgNP) sensing system is presented. First, silver nanoparticles were prepared by reducing AgNO3 with sodium borohydride in the presence of chitosan and different organic acids, including acetic acid, propanedioic acid, and citric acid. The addition of different organic acids allowed for the surface plasmon resonance (SPR) intensity and size distribution of the AgNPs to be adjusted. Chitosan acts as a stabilizer and complexing agent, endowing AgNPs with excellent film-forming properties. Then, the chitosan-stabilized AgNPs in the solvent and solidfilm state are used to detect metal ions. In the presence of Hg2+ and Pd2+ ions, the color of the AgNP solution changed rapidly from pale yellow to colorless and light brown, respectively. The characteristic SPR peaks of the AgNPs also disappeared completely, and the solid films of AgNPs with a yellowish-brown color also changed rapidly to colorless and dark brown with the addition of Hg2+ and Pd2+ ions, respectively. The discrimination of Hg2+ and Pd2+ ions can be clearly observed in both the solvent and the solid film state. However, the addition of other metal ions cannot change the color of the AgNPs. [ABSTRACT FROM AUTHOR]

Scopolamine and promethazine can be used as a substitute for heroin. It is relatively fast and simple to use surface-enhanced Raman spectroscopy (SERS) for the detection and monitoring of drug usage. Silver nanosol is an enhanced substrate that is commonly used in the SERS technique; the Raman signal of the sample is amplified by the substrate. However, for the detection of mixtures, the competitive adsorption of different components relative to the substrate will result in difficult qualitative identification of spectra. By taking advantage of this defect, the adsorbed components of a mixture were separated from silver nanoparticles by centrifugation, thus changing the mixing ratio of the two components in the mixture. As a result, the proportion of the components with strong adsorption in the mixture is relatively reduced. Thus, the components with weak adsorption can be displayed in the spectrum of the mixed solution. [ABSTRACT FROM AUTHOR]

In this article, we demonstrate a sensitive surface-enhanced Raman spectroscopy (SERS) substrate for trace dimethoate detection. The substrate is composed of a silver nanopartide-probe-smooth gold film stack configuration. The nanogap formed by a silver nanopartide and a macroscopically flat gold film is one kind of "hot site" that will dramatically increase the total "hot spots" number. [ABSTRACT FROM AUTHOR]

The article focuses on research related to formation of silver nanoparticles from bacteria encapsulin by researchers Pamela A. Silver and Tobias W. Giessen. It mentions use of silver nanoparticles in antimicrobial coatings for bandages and clothing. It presents views of professor Todd O. Yeates on use of microbes for large-scale manufacture needing less toxic chemicals.

The article features an application note to test how well surface enhanced Raman spectroscopy (SERS) substrates of Ocean Optics can detect traces of cocaine, heroin, methamphetamine, and tetrahydrocannabinol (THC). For the measurements, gold and silver nanoparticles and a 785 nanometer (nm) laser for Raman excitation were used. The resulting Raman spectra showed that using Ocean Optics SERS substrates can detect illicit drugs.

The article reports on the study led by Peter Kopittke, senior lecturer in soil science at the University of Queensland School of Agriculture and Food Sciences, which suggests the increase risk posed by silver nanoparticles in saline soils and in soils irrigated with poor quality water.

The article focuses on chemistry-related research published in 2015 issues of various journals. Topics include a study by researchers Susana C.M. Fernandes and Vincent Bulone on use of materials containing ultraviolet-absorbing molecules found in algae and reef-fish mucus in sunscreens; research by researcher Hongbing Fu on organic infrared lasers; and a study by researchers Pedro J.J. Alvarez and Yu Yang on effectiveness of concentrations of silver nanoparticles in microbes' resilience.

The article reports on a lawsuit filed by a coalition of environmental and public health groups against the U.S. Environmental Protection Agency for failing to assess risks to humans and the environment in approving the use of Nanosilva, a nanosilver-based pesticide, in textiles and plastics.

In this article, the author focuses on harmful effects of biofilms including lupus, catheter infections and urinary tract infections and mentions a research which reveals that silver nanoparticles (AgNPs) exposure can lead to enhanced biofilm development.

The article reports on the installation of arsenic water treatment tanks using nanocomposite granules developed at the Indian Institute of Technology (IIT), Madras for the low-cost and point-of-use water treatment to provide clean water to the community. Topics discussed include nanocomposites made from ferric oxyhydroxide and chitosan, a biopolymer, funding for the experiment given by the government, and impregnation of nanacomposites with silver nanoparticles to remove microbes.

The article discusses a study from the University of Fribourg, Switzerland led by Katharina Fromm entitled "One-pot synthesis and catalytic properties of encapsulated silver nanoparticles in silica nanocontainers" on a method to improve biomedical implants to prevent microbial biofilm growth.

The article focuses on a study by Vivek Subramanian and Tsu-Jae King Liu, researchers at the University of California, who printed microelectromechanical systems (MEMS) switches using silver nanoparticle inks as of October 2013.

The article reports on a study by Xiao (Matthew) Hu, a scientist at Nanyang Technological University, and colleagues, published in the journal "Environmental Science & Technology," in which they developed a porous gel embedded with silver nanoparticles that kills bacteria and disinfects water.

The article discusses a study published in "Proceedings of the National Academy of Sciences" about Indian Institute of Technology Madras chemists' development of an affordable silver nanoparticle water filter that could be used by households with no access to clean water.

The article reports that Iranian chemical engineers have claimed that silver nanoparticles can be used to improve methane hydrate formation for the transportation of natural gas.

The article presents information on a study regarding the mechanism behind killing of bacteria by silver nanoparticles found in consumer products. According to the study, the silver ions emitted from the nanoparticles are responsible for the killing of bacteria. Manufacturers of consumer products use silver nanoparticles in the cosmetics and clothing to kill germs.

The article presents information about the reviewing of pesticides with silver nanoparticles by the U.S. Environmental Protection Agency in order to check the environmental aspects of physical and chemical properties of the silver.

The article reports on a law suit filed by the Natural Resources Defense Council (NRDC) to obstruct the U.S. Environmental Protection Agency's (EPA) conditional approval of nanosilver antimicrobial materials.

The article focuses on the microbicidal silver nanoparticles prepared by the researchers led D. Matthew Eby and Glenn R. Johnson of the U.S. Air Force Research Laboratory at Tyndall Air Force Base in Florida. The antimicrobial solution was prepared by exposing to light the combined enzyme lysozyme from chicken egg whites and silver acetate in methanol. Assays revealed that the antimicrobial solution can control the growth of Escherichia coli, Staphylococcus aureus, and Bacillus anthracis.

The article highlights the results of a study on how nanoparticles are released from commercially available clothing. According to researchers Troy M. Benn and Paul Westerhoff at Arizona State University, socks impregnated with odor-fighting silver nanoparticles release the nanoparticles when washed. They explain that the sock manufacturing process may control how much silver is released during washing because the amounts varied widely among the socks they tested.

Reports on the antibiotic activity of nanocomposite fibers formed by incorporating silver nanoparticles into surfaces of polypropylene strands.