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A new methodology toward biodefense and threat surveillance by water-dispersible, bactericidal, paramagnetic nanoparticles is presented. The nanoparticles consist of magnetite clusters (~70 nm) modified by polyethyleneimine (PEI) and poly(hexamethylene biguanide) (PHMBG) and are prepared by a two-step procedure at an acceptable cost. The cationic nanoparticles are colloidally stable in water at pH [less than or equal to] 10, where they sequester DNA or whole microbes. The nanoparticles and bound DNA are captured by high-gradient magnetic separation. Methods of efficient extraction and quantification of the DNA by real-time PCR are developed. Broad bactericidal activity of the nanoparticles is demonstrated at concentrations far below cytotoxicity levels for mammalian cells. The levels of the DNA detection sensitivity obtained in our experiments allow us to project the applicability of the developed method for the detection of DNA molecules of various germs.

The photoresponsive interaction of light-sensitive azobenzene surfactants with bovine serum albumin (BSA) at neutral pH is investigated as a means to control protein folding with light irradiation. The results demonstrate that the visible-light form of the surfactant causes a greater degree of protein unfolding than the UV-light form, providing a means to control protein folding with light that, within the resolution of small-angle neutron-scattering (SANS), appears to be completely reversible.

The enzyme xanthine oxidase, which is stable and active close to many surface interfaces and water, is used for analyzing reversed micellar enzymatic activity. The partitioning of charged substrates effects the enzymatic reactivity in reversed micelles, and it gives the differences between the enzyme kinetics of water and micellar systems. The specificity ratio decreases, in comparison to water, for three surfactant systems with interfaces of different polarity.

N-vinylpyrrolidone/styrene (NVPS) can be use in enhancing the solubilization of several model hydrophobic aromatic compounds in aqueous solutions. Results of a study investigating the viability of using NVPS as an alternative to the carbon adsorption and solvent extraction methods of liquid waste concentration indicate that organic solubilization in water is enhanced to a greater degree by NVPS than other miscellar surfactants. This shows the feasibility of using NVPS and other similar copolymer surfactants in environmental remediation applications.

We report two fluorophores, N-(1-pyrenylmethyl)-1-pyrenebutanamide and N-(1-pyrenylmethyl)-1-pyreneacetamide, that exhibit temperature-dependent emission spectra over the temperature range of 25620-100 [degrees] C. The fluorophores are readily synthesized via a one-pot process and can be used in dilute form (

Scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy were employed to study the polymer substrates functionalized with a metal-organic frameworks (MOF) material (MIL-47) as a function of microwave irradiation. The findings provides route for the development of a new class of hybrid MOF-polymer materials that would extend the applications of MOFs to fields such as membrane separations, filtration and protective textiles.

Patterned engineered surfaces are used for crystallizing glycine with a lateral dimension below 200 nm in a confined volume while controlling supersaturation. Individual crystals are characterized with AFM and Raman spectroscopy and the solubility enhancement is measured as a function of crystal size.

Janus magnetic nanoparticles are prepared by grafting either polystyrene sodium sulfonate (PSSNa) or polydimethylamino ethylmethacrylate (PDMAEMA) to the exposed surfaces of negatively charged poly(acrylic acid) (PAA)-coated magnetite nanoparticles. The addition of small amounts of PAA-coated magnetic nanoparticles to the Janus nanoparticle suspension results in the increase in the final cluster area.

In this paper, an amino-functionalized adsorbent for CO2 capture was synthesized by impregnating 3-aminopropyltriethoxysilane (APTES) on mesoporous silica. Amino functional groups were chemically bonded to silica support. Because of chemical bonds, the thermal stability of this adsorbent (205 °C) was greater than that of an adsorbent prepared by impregnating polyethylenimine on the same mesoporous silica (160 °C). The cyclic CO2 loading capacity was improved by increasing adsorption temperature, reaching a maximum of 89.3 mg CO2/g at 100 °C and then reduced at temperatures above 100 °C. Optimum regeneration temperature was determined at 120 °C. The adsorbent was stable for multiple adsorption-regeneration cycles operating at adsorption temperature of 100 °C in pure CO2 and regeneration temperature of 120 °C in atmosphere, respectively. The amino-functionalized mesoporous silica is a thermally stable adsorbent with relatively high CO2 loading capacity and high optimum adsorption and regeneration temperatures. These characteristics make the adsorbent suitable for CO2 capture application. [ABSTRACT FROM AUTHOR]

The photoactivated inherent fluorescence resonance energy transfer (FRET) properties of a hard-and-soft hybrid nanosystem comprising poly(1'-(2-methacryloxyethyl)-3',3'-dimethyl-6-nitrospiro-(2H-1-benzopyran-2,2'-indoline))- co-poly[2-(dimethylamino)ethyl methacrylate] (PSPMA-co-PDMAEMA) random copolymer brushes on silica nanoparticles are described. This unique FRET process is switched on by the simultaneous generation of isomer X and merocyanine (MC), which are bipolar in nature and comprise donor-acceptor dyads, from a single spiropyran (SP) chromophore upon UV irradiation. These X-MC species exhibit sufficient lifetimes to allow the read-out of the FRET process. The phenomenon is gradually switched off because of the thermal relaxation of the bipolar chromophores. This inherent property of the nanoemitters is employed in the development of biosensors of high specificity by monitoring variations in the FRET efficiency and lifetime of the hybrids in the presence of biological substances. More specifically, bovine serum albumin (BSA) augments the formation of MC species and retards the MC photobleaching process, leading to the enhancement of the FRET efficiency and lifetime, respectively. On the other hand, amino acid l-histidine further retards the MC thermal relaxation and prolongs the FRET process. We envisage that this platform opens new perspectives in the development of novel, optical nanosensors for applications in various fields including healthcare products and environmental monitoring. [ABSTRACT FROM AUTHOR]