A facile way for preparing tin nanoparticles from bulk tin via ultrasound dispersion

Sn-based film electrodeposited on Ag foil for selective electrochemical CO2 reduction to CO

Electrochemical CO2 reduction (ECR) to valuable chemicals and fuels using renewable energy is a promising way to reduce carbon emission. Herein, Sn-based films were electrodeposited on Ag foil surfaces (Sn/Ag-y) for selective ECR to CO, where y represented the concentration of SnCl2 in the electrodeposition bath. The Sn/Ag-20 electrode achieved a high CO faradaic efficiency of 96.0% with a current density of 69.3 mA cm-2. The enhanced catalytic performance could be attributed to appropriate superficial properties, large electrochemical active surface areas, low charge transfer resistance, efficient stabilization capacity of the CO2˙- intermediates, and suitable combination with electrolytes.

Formation of Metal Nanoparticles Directly from Bulk Sources Using Ultrasound and Application to E-Waste Upcycling

A method for creating nanoparticles directly from bulk metal by applying ultrasound to the surface in the presence of a two-part surfactant system is presented. Implosive collapse of cavitation bubbles near the bulk metal surface generates powerful microjets, leading to material ejection. This liberated material is captured and stabilized by a surfactant bilayer in the form of nanoparticles. The method is characterized in detail using gold, but is also demonstrated on other metals and alloys, and is generally applicable. It is shown that nanoparticles can be produced regardless of the bulk metal form factor, and the method is extended to an environmentally important problem, the reclamation of gold from an electronic waste stream.

β-Lactoglobulin microparticles obtained by high intensity ultrasound as a potential delivery system for bioactive peptide concentrate

This work attempted to assess the effect of high intensity ultrasound (HIUS) upon development of bio-based delivery systems, from β-lactoglobulin (β-Lg) gelled microparticles, for encapsulation of a bioactive peptide concentrate (PepC). Solutions of 150 g L^-1 of commercial β-Lg and 30 g L^-1 PepC, at various pH values (3.0, 4.0 and 5.5), were accordingly subjected to gelation for 30 min using a dry bath kept at 80 °C. The gelled systems were then exposed to HIUS at 0-4 °C, and the effect of processing time (2.5-20.0 min) was ascertained. Laser light scattering and confocal microscopy were used to characterize the particle size distribution, prior to and immediately after HIUS treatment. Gels obtained at pH 5.5 and 4.0 were harder than those obtained at pH 3.0. Ultrasound treatment of gels produced an important reduction in particle mean diameter as sonication time elapsed. Confocal microscopy indicated that application of HIUS led to almost round and monodispersed particles, at both pH 5.5 and 4.0. The peptide encapsulation efficiency was assessed by chromatography and accompanied by assay for bioactivity, after precipitation of the encapsulated material and analysis of the soluble peptides therein.

De novo design of chiral organotin cancer drug candidates: validation of enantiopreferential binding to molecular target DNA and 5'-GMP by UV-visible, fluorescence, (1)H and (31)P NMR

N,N-bis[(R-/S-)-1-benzyl-2-ethoxyethane] tin (IV) complexes were synthesized by applying de novo design strategy by the condensation reaction of (R-/S-)2-amino-2-phenylethanol and dibromoethane in presence of dimethyltin dichloride and thoroughly characterized by elemental analysis, conductivity measurements, IR, ESI-MS, (1)H, (13)C and (119)Sn, multinuclear NMR spectroscopy and XRD study. Enantioselective and specific binding profile of R-enantiomer 1 in comparison to S-enantiomer 2 with ultimate molecular target CT-DNA was validated by UV-visible, fluorescence, circular dichroism, (1)H and (31)P NMR techniques. This was further corroborated well by interaction of 1 and 2 with 5'-GMP.

Alhydrogel® adjuvant, ultrasonic dispersion and protein binding: a TEM and analytical study

Aluminium-based vaccine adjuvants have been in use since the 1920s. Aluminium hydroxide (alum) that is the chemical basis of Alhydrogel, a widely used adjuvant, is a colloid that binds proteins to the particular surface for efficient presentation to the immune system during the vaccination process. Using conventional TEM and cryo-TEM we have shown that Alhydrogel can be finely dispersed by ultrasonication of the aqueous suspension. Clusters of ultrasonicated aluminium hydroxide micro-fibre crystals have been produced (∼ 10-100 nm), that are significantly smaller than those present the untreated Alhydrogel (∼ 2-12 μm). However, even prolonged ultrasonication did not produce a homogenous suspension of single aluminium hydroxide micro-fibres. The TEM images of unstained and negatively stained air-dried Alhydrogel are very similar to those obtained by cryo-electron microscopy. Visualization of protein on the surface of the finely dispersed Alhydrogel by TEM is facilitated by prior ultrasonication. Several examples are given, including some of medical relevance, using proteins of widely ranging molecular mass and oligomerization state. Even with the smaller mass proteins, their presence on the Alhydrogel surface can be readily defined by TEM. It has been found that low quantities of protein tend to cross-link and aggregate the small Alhydogel clusters, in a more pronounced manner than high protein concentrations. This indicates that complete saturation of the available Alhydrogel surface with protein may be achieved, with minimal cross-linkage, and future exploitation of this treatment of Alhydrogel is likely to be of immediate value for more efficient vaccine production.

DNA interaction studies of new nano metal based anticancer agent: validation by spectroscopic methods

A new nano dimensional heterobimetallic Cu-Sn containing complex as a potential drug candidate was designed, synthesized and characterized by analytical and spectral methods. The electronic absorption and electron paramagnetic resonance parameters of the complex revealed that the Cu(II) ion exhibits a square pyramidal geometry with the two pyrazole nitrogen atoms, the amine nitrogen atom and the carboxylate oxygen of the phenyl glycine chloride ligand located at the equatorial sites and the coordinated chloride ion occupying an apical position. (119)Sn NMR spectral data showed a hexa-coordinated environment around the Sn(IV) metal ion. TEM, AFM and XRD measurements illustrate that the complex could induce the condensation of CT-DNA to a particulate nanostructure. The interaction of the Cu-Sn complex with CT-DNA was investigated by UV-vis absorption and emission spectroscopy, as well as cyclic voltammetric measurements. The results indicated that the complex interacts with DNA through an electrostatic mode of binding with an intrinsic binding constant K(b) = 8.42 x 10(4) M( - 1). The Cu-Sn complex exhibits effective cleavage of pBR322 plasmid DNA by an oxidative cleavage mechanism, monitored at different concentrations both in the absence and in the presence of reducing agents.

Preparation of In2S3 nanopraricle by ultrasonic dispersion and its tribology property

In this paper, we describe a facile and rapid method for preparing In2S3 nanoparticles via ultrasound dispersion. This method allows us to prepare In2S3 nanoparticles from bulk indium and sulfur with ease and without using expensive agents and in a short time. The possible growing mechanism of the In2S3 nanoparticles was presented. In addition, we provide detailed characterizations including TEM, XRD, TG-DTA, and XPS to study the shape, composition and structure of In2S3 nanoparticles. We also studied the tribology property of In2S3 nanoparticles made using this novel recipe.