Spectrometry researches on interaction and sonodynamic damage of riboflavin (RF) to bovine serum albumin (BSA).

In this paper, the riboflavin (RF) was used to study the interaction and sonodynamic damage to bovine serum albumin (BSA) by fluorescence and UV-vis spectroscopy. The results showed that the RF could efficiently bind to BSA in aqueous solution. Under ultrasonic irradiation, the RF could obviously damage the BSA. In addition, synchronous fluorescence spectroscopy revealed that the RF showed more accessible to tryptophan (Trp) residues than to tyrosine (Tyr) residues. Also, it damaged Trp residues more seriously than Tyr residues under ultrasonic irradiation. At last, the generation of reactive oxygen species (ROS) in sonodynamic process was estimated by the method of Oxidation-Extraction Spectrometry (OES). And then, several radical scavengers were used to determine the kind of ROS. It was found that at least the singlet oxygen ((1)O(2)) and hydroxyl radicals (*OH) were generated.

Preparation and characterization of an ultrathin carbon shell coating a silver core for shell-isolated nanoparticle-enhanced Raman spectroscopy.

A well-designed type of ultrathin carbon shell coating a silver core was prepared for the first time through an alternate adsorption and carbonization method. The obtained ultrathin carbon shell shows prominent advantages, including sufficient uniformity, better chemical stability than silica or alumina, biocompatibility, being free of pin-holes and low cost.

Directed calcium chloride coalescence method for preparation of silver nanocubes.

Controlling the size, shape, and structure of metal nanoparticles is very important because of the strong correlation between these parameters and their resulting optical, electrical, and catalytic properties. This paper describes a directed calcium chloride coalescence method, based upon incubating a silver colloid with an aqueous solution of CaCl(2), for preparation of silver nanocubes with a particle size of 270 to 950 nm. The method avoids the use of nonvolatile surfactants and polymers, which may be adsorbed onto the silver nanocubes and interfere with their possible applications in catalysis and analytical devices based on surface-enhanced Raman scattering (SERS) spectroscopy. The nanocubes show good SERS activity in the presence of adsorbed 4-mercaptobenzoic acid (4-MBA) with excitation at 632.8 nm, and the enhancement factor reaches approximately 7 x 10(5). The nanocubes are produced in a simple and cost-effective way, and they are expected to play an important role in the development of SERS-based analytical devices. The method may represent a novel route for preparation of metal nanocubes, which is a subject of intense interest.