Details

Autor(en) / Beteiligte

• Kumar-Krishnan, Siva
• Prokhorov, Evgen
• Hernández-Iturriaga, Monserrat
• Mota-Morales, Josué D.
• Vázquez-Lepe, Milton
• Kovalenko, Yuri
• Sanchez, Isaac C.
• Luna-Bárcenas, Gabriel

Titel

Chitosan/silver nanocomposites: Synergistic antibacterial action of silver nanoparticles and silver ions

Ist Teil von

• European polymer journal, 2015-06, Vol.67, p.242-251

Ort / Verlag

Elsevier Ltd

Erscheinungsjahr

2015

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Chitosan–Ag nanocomposites; the optimum concentration of AgNP’s for the inhibition of microorganism’s growth is close to the percolation threshold of ca. 1wt.% (a1, a2). Note Ag concentration shifts to ca. 2wt.% for chitosan–Ag ion films (b1, b2). [Display omitted] •A green chemistry approach to produce chitosan–Ag nanocomposites.•Electrical, structural and antibacterial properties are highly correlated.•Bactericide potency studied against S. aureus and E. coli.•Chitosan–Ag films (<10nm) exhibited highest bactericide potency. In the present work chitosan–silver (CS/Ag) nanocomposites, either in the form of nanoparticles (AgNP) or as ionic dendritic structures (Ag+), are synthesized by a simple and environmentally friendly in situ chemical reduction process. The antibacterial activity of the resulting nanocomposites in the form of films is studied against two bacteria, Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. The relationship between electrical, structural and antibacterial properties of CS/AgNP and CS/Ag+ nanocomposites are studied by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction, and UV–Vis, impedance, infrared and X-ray photoelectron spectroscopies. The results demonstrate that in contrast to CS/Ag+ ion films, the CS/AgNP composites films (average particle size less than 10nm) showed a significantly higher antibacterial potency. The collective action of AgNP and Ag+ ions facilitate the enhancement and synergetic antibacterial activity below certain critical concentration. The bactericide activity of both CS/AgNP and CS/Ag+ ion composite films increases by increasing the concentration of Ag. The composites containing 1wt.% of silver nanoparticles and about of 2wt.% of silver ions exhibit a maximum antibacterial activity, which is close to their electrical percolation threshold. The concentration of AgNP and Ag+ ions above the threshold level greatly diminish the antibacterial potential.