The antibacterial activity of various nanoparticles is gaining increasing interest due to its potential medical applications. In this work, we presented the synthesis of copper oxide nanoparticles prepared by chemical reduction from aqueous solutions of copper sulfate (CuSO 4) with sodium borohydride (NaBH 4) and hydrazine hydrate (N 2 H 4) as reductant and polyvinylpyrrolidone (PVP) as stabilizer. The X-ray diffraction spectra showed the formation of tenorite (CuO) and cuprite (Cu 2 O) nanoparticles when different ratios of CuSO 4 /NaBH 4 and CuSO 4 /N 2 H 4 were used. Photographs obtained by transmission electron microscopy (TEM) showed agglomerates of grains with a narrow size distribution (from 20 to 70 nm), whereas the radii of the individual particles were between 2 and 20 nm. Smaller nanoparticles and narrower particle size distributions were obtained when NaBH 4 was used. The results of antibacterial activity using the Kirby-Bauer method showed that nanoparticles obtained with NaBH 4 presented a reasonable bactericidal activity. Pseudomonas aureginosa and Staphylococcus aureus were more susceptible to the particle size than Escherichia coli. In addition, with small amounts of Cu 2 O in samples of CuO nanoparticles, the antibacterial susceptibility against Pseudomonas aureginosa was improved. Finally, nanoparticles of CuO incorporated into cotton by applying ultrasound waves remained impregnated after five washes.

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A procedure for the determination of chromium in wine by differential pulse adsorptive stripping voltammetry (DPAdSV), using different complexing agents (TTHA, DTPA and Cupferron), has been optimized. The selection of the experimental conditions was made using experimental design methodology. Under these conditions the calibrations were made and the detection limit was determined for each complexing agent. The lowest detection limit (4.68610 À10 mol dm À3) was obtained with DTPA and for this reason it was selected for the determination of the concentration of chromium in different wine samples, after having conducted a previous optimization of the experimental factors.