The surface-enhanced Raman scattering (SERS) spectra of maleic (cis; 2-butaneoic acid) and fumaric (trans; 2-butaneoic acid) acids adsorbed on aqueous silver sol particles are reported. These two acids form two groups of isomers which differ only in the relative positions of the two carboxylate groups. The photochemistry of maleic and fumaric acids adsorbed on the surface of silver colloids...

We show how to create arrays of biosensors by in situ assembly of colloidal particles onto micropatterned electrodes. Latex microspheres from suspension are collected via dielectrophoresis in the micrometer-sized gaps between planar electrodes. The assembled particulate patches are fixed by changing the colloidal interactions to induce coagulation. Immuno-active sites on the latex surfaces bind...

We report the results of treating a dense, chemically produced silver colloidal suspension with high-power laser pulses and with exposure to supercritical water (SCW) conditions. The initial colloid has a mean particle diameter measured by transmission electron microscopy to be 28.4 nm and exhibits a broad absorption band in the visible region with a small maximum near 420 nm. Both treatments r...

Background: Nanoparticles have been applied to medicine, hygiene, pharmacy and dentistry, and will bring significant advances in the prevention, diagnosis, drug delivery and treatment of disease. Green synthesis of metal nanoparticles has a very important role in nanobiotechnology, allowing production of non-toxic and eco-friendly particles.Objectives: Gr...

Pulsed laser ablation (PLA) has become a promising method for the synthesis of nanoclusters for photonics, electronics and medicine. In this work PLA in pressurized CO2 has been applied for fabrication of gold and silver nanoparticles. Laser ablation was performed with an excitation wavelength of 532 nm under various pressures (0.1–20MPa), temperatures (40–80 C) of CO2 medium and ablation times...

Multimetal deposition is a versatile technique of detecting latent fingerprints on porous items, for example, fabric tape, masking tape, cardboard; on semi-porous items, for example, expanded polystyrene, latex gloves, waxed paper; as well as on non-porous items, for example, metals and plastics. It is so named because it is a two-step process, the first involves deposition of gold and the seco...

In 1884, Metchnikoff (1) presented his studies of phagocytosis and concluded that the process was a general reaction that removed particulate matter from the circulation. Highly mobile cells, the polymorphonuclear leukocytes, were observed to ingest microorganisms and other particulate matter, such as pus, corpuscular elements of extravasated blood, and foreign cells. In addition to these circu...